Re: [time-nuts] Li-ion Battreries

[William H. Fite]

Whatever makes you feel safe, Mark. The internet has a plenitude of horror
stories, some of which would make you think that the only prudent course
was to store them in an underground bunker.

Our study used several hundred batteries, all stored in surplus cal .50
ammunition cases in manufacturers' packaging. We had no explosions, no
fires, no spontaneous combustions, no drama at all.

But do what makes you feel safe, by all means.



On Sunday, January 22, 2017, Mark Sims  wrote:

> They can be if you store them in something like an ammo box.   If they "go
> off" in the sealed box the pressure builds,  the reaction rate increases
> exponentially,  and voila... shrapnel time.   There's a video out there
> showing the results.
>
> Most people recommend storing them in nomex/kevlar "cell bags".   I keep
> mine, bagged,  in an unused/unplugged oven!  If one goes off,  hopefully
> the flames won't spread to the rest of the property and the hinged oven
> door allows pressure to escape.
>
> Hobby RC packs are one of the most dangerous type of rechargeable lithium
> cells out there... even from "reputable" sources and brands.   A local
> hobby shop twice had  brand new name brand packs sitting on the shelf go
> off.  A friend of mine had the same thing happen carrying a just purchased
> pack home in his car.
>
> 
>
> > They aren't bombs, guys.  Use sensible precautions and get on with it
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-- 
If you gaze long into an abyss, your coffee will get cold.
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Re: [time-nuts] Li-ion Battreries

[MLewis]

Those hobby packs are typically LiPO, chosen for the energy density, and 
they often (usually?) run them with minimal protection circuits to 
reduce weight. Not recommended practice for building devices.


BMS
When I built a 12 cell series 10Ah pack, I went with LiFePO4 and a 
custom-configured Battery Management System (BMS). The BMS doesn't 
balance the charge after charging (which consumes time & energy), but 
runs a separate lead to each junction between cells so it can monitor 
each cell to vary each cell's charging to bring each to cell Vmax 
without going over. Those leads also allow each cell to be monitored 
against under voltage (cell Vmin). The cheap alternate is to rely upon 
monitoring pack Vmax and pack Vmin protection, but this is a recipe for 
killing a cell, as a cell may go over or under voltage while the pack 
voltage appears within the safe range.


The LiFePO4 cell I chose is interesting for its self-containment. 
Headway 38120, which was recommended as the cell is built encased within 
a containment shell with a threaded terminal on each end. The negative 
end's terminal is entirely sealed. The positive end's terminal is also 
sealed, but there are air holes spaced around the cap-to-container join 
and the true seal is an inner cap under that terminal cap (visible 
through those holes). When the cell fails, rather than pressure causing 
a leak, the inner sealing cap can expand into the space under the 
terminal cap thereby relieving a critical level of pressure. Or so it's 
claimed; I've never had an incident to test that.


Michael


On 22/01/2017 9:25 PM, Mark Sims wrote:

Hobby RC packs are one of the most dangerous type of rechargeable lithium cells 
out there...


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Re: [time-nuts] purpose of time of day display units

[Chris Albertson]

I do stuff like that too.   I always like to use an I2C connected LCD
display while developing code on any micro processor project.  I might take
the actual LCD off at the end but I always leave the signal pins in place.
I might need to debug the device again some time and then I can find
another display.  I see a lot of this in commercial products, for example a
USB connection on the back of my TV, only for diagnostic use.

Same with "heartbeat" LEDs, they let you know the device is cycling through
its main pressing loop and not hung.

On Sun, Jan 22, 2017 at 4:26 PM, Hal Murray  wrote:

>
>
> Is there a term similar to "eye candy" for geeks?
>
> Many years ago, I designed network gear.  That was back when a controller
> was
> a board full of small and medium sized chips rather than a single big chip.
> I always put a few LEDs on the board wired up where the microcode could get
> at them.  Most of the time they were just eye candy.  But occasionally I
> would borrow one and hack the microcode so a LED would be interesting on a
> scope.
>
>
>
>
> --
> These are my opinions.  I hate spam.
>
>
>
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> and follow the instructions there.
>



-- 

Chris Albertson
Redondo Beach, California
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[time-nuts] galileo-atomic-clock-failures

[Arnold Tibus]

Perhaps of general interest for time-nuts:

http://spaceflight101.com/galileo-atomic-clock-failures/
https://www.spaceintelreport.com/galileo-clocks

kind regards

Arnold, DK2WT


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[time-nuts] Li-ion Battreries

[Mark Sims]

They can be if you store them in something like an ammo box.   If they "go off" 
in the sealed box the pressure builds,  the reaction rate increases 
exponentially,  and voila... shrapnel time.   There's a video out there showing 
the results.   

Most people recommend storing them in nomex/kevlar "cell bags".   I keep mine, 
bagged,  in an unused/unplugged oven!  If one goes off,  hopefully the flames 
won't spread to the rest of the property and the hinged oven door allows 
pressure to escape.

Hobby RC packs are one of the most dangerous type of rechargeable lithium cells 
out there... even from "reputable" sources and brands.   A local hobby shop 
twice had  brand new name brand packs sitting on the shelf go off.  A friend of 
mine had the same thing happen carrying a just purchased pack home in his car.



> They aren't bombs, guys.  Use sensible precautions and get on with it
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Re: [time-nuts] purpose of time of day display units

[Ruslan Nabioullin]

On 01/22/2017 07:26 PM, Hal Murray wrote:

Many years ago, I designed network gear.  That was back when a controller was
a board full of small and medium sized chips rather than a single big chip.
I always put a few LEDs on the board wired up where the microcode could get
at them.  Most of the time they were just eye candy.  But occasionally I
would borrow one and hack the microcode so a LED would be interesting on a
scope.


Ah, just like those status LEDs on PCBs, subsystems, and modules in 
properly-engineered equipment (both old and modern minicomputers, 
aerospace equipment, VME and VXI systems, some other servers [some of 
HP's small servers, at least, even feature a neat diagram on the front 
panel, with status LEDs indicating the status of key subsystems or 
components thereof], etc.)  Apple's hardware obviously is an offender in 
this regard---I remember once having to service an iMac (or some other 
modern Apple PC), and I seriously could not figure out how to turn it 
on, and when I had to temporarily shut off the power distribution 
system, I could not figure out what the PC's power state was (to ensure 
a graceful shutdown of the system).


-Ruslan
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Re: [time-nuts] purpose of time of day display units

[Jeremy Nichols]

I have done something similar to one of my cars so that, for example, an
LED that tells me when the a/c compressor's electric clutch cycles on and
off. Things like this are partly eye candy, partly educational (things
don't always work quite like I assume they do), and partly a valuable
diagnostic tool when something breaks.

Jeremy


On Sun, Jan 22, 2017 at 6:01 PM Hal Murray  wrote:

> jim...@earthlink.net said:
>
> > 3) It's a crude visual check - your eye/brain is pretty good at
> catching  a
>
> > change in the pattern of blinky lights.  IN this situation, you'd  expect
>
> > all the displays to change simultaneously.
>
>
>
> Is there a term similar to "eye candy" for geeks?
>
>
>
> Many years ago, I designed network gear.  That was back when a controller
> was
>
> a board full of small and medium sized chips rather than a single big chip.
>
> I always put a few LEDs on the board wired up where the microcode could get
>
> at them.  Most of the time they were just eye candy.  But occasionally I
>
> would borrow one and hack the microcode so a LED would be interesting on a
>
> scope.
>
>
>
>
>
>
>
>
>
> --
>
> These are my opinions.  I hate spam.
>
>
>
>
>
>
>
> ___
>
> time-nuts mailing list -- time-nuts@febo.com
>
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>
> and follow the instructions there.
>
> --
Sent from Gmail Mobile
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Re: [time-nuts] purpose of time of day display units

[Scott Stobbe]

There is a lot to be said about a tool that just works. In the advent of a
piece of gear failing whether that be a firmware bug or a cooling fan, or
more severe, having a known diagnostic tool during that time is priceless
(well maybe not priceless but extremely nice to have).

On Sun, Jan 22, 2017 at 1:31 AM, Ruslan Nabioullin 
wrote:

> Hi, looking at pictures of various time metrology equipment setups for
> best practices and inspiration, I have commonly seen time of day display
> unit(s) installed in racks containing processing or time transfer
> equipment, e.g., http://www.xyht.com/wp-content/uploads/2015/05/Powers_
> Master_Clock.jpg. All that these units do is merely display the time of
> day and sometimes the date, typically by means of seven segment LED
> displays, of the time code inputted to them (typically IRIG-B, I'm
> guessing).  Any ideas why such a unit is necessary when one can simply look
> at the time displayed by timing receivers and time code generators (and
> even some standards), and the interface of some fusor, defined in this
> context as a system which performs timing data fusion (by implementing a
> paper clock or a more primitive algorithm) and timekeeping, either by means
> of a direct shell, or via something like NTP?
>
> Thanks in advance,
> Ruslan
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Re: [time-nuts] HP 5061A/B Cesium tube conundrum

[paul swed]

Corby
Curious if you ever received any other comments or had success?
Regards
Paul
WB8TSL

On Mon, Jan 16, 2017 at 5:07 PM, paul swed  wrote:

> Corby thats a heck of a puzzle. I am trying to think about how you could
> prove it. I have some thoughts that are not at all well formed. It comes
> from my experiments on Frankenstein temp control.
>
> If you could please tell me what you might expect the alternate bridge
> resistors to be overall I will look through my various bits to see if there
> is anything.
>
> Regards
> Paul
> WB8TSL
>
> On Mon, Jan 16, 2017 at 3:58 PM,  wrote:
>
>> I've been doing some work on testing some HP 5061A/B tubes
>> and came across something that's not making any sense!
>> The R11 and R12 values marked on the tubes for use with the
>> new style A11 are supposed to reflect a parallel value
>> that is 10X larger than the thermistor reading.
>> This to agree with the ratio of the bridge resistors in the
>> A11 module.
>> For instance a 3112A prefix tube shows values of 3.83K
>> and 42.2K. This gives a parallel value of 3.511K which when
>> divided by 10 gives 351.1 Ohm. The value marked on the tube
>> was 352 Ohm. That all makes sense!
>> Now I have three 3232A prefix tubes and they all do not
>> reflect this ratio.
>> For instance one has values of 51.1K and 5.11K which gives
>> 4.65K. This divided by ten gives 465 Ohms. However the
>> Thermistor value marked on the tube is 915 Ohms!
>> I tested all three tubes and they come up to the proper
>> temperature with the thermistor value marked on the tube.
>> Did HP make a change to the A11 bridge resistor ratio, and
>> if so where did they document it!
>> If not and you used the R11 and R12 values you would
>> seriously overheat the tube!
>>
>> Cheers,
>>
>> Corby
>>
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>>
>
>
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Re: [time-nuts] purpose of time of day display units

[Hal Murray]

jim...@earthlink.net said:
> 3) It's a crude visual check - your eye/brain is pretty good at catching  a
> change in the pattern of blinky lights.  IN this situation, you'd  expect
> all the displays to change simultaneously. 

Is there a term similar to "eye candy" for geeks?

Many years ago, I designed network gear.  That was back when a controller was 
a board full of small and medium sized chips rather than a single big chip.  
I always put a few LEDs on the board wired up where the microcode could get 
at them.  Most of the time they were just eye candy.  But occasionally I 
would borrow one and hack the microcode so a LED would be interesting on a 
scope.




-- 
These are my opinions.  I hate spam.



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[time-nuts] Manual and Software for R (Meinberg) ED170MP GPS Receiver?

[Dave Hallidy]

All-

I just acquired a Rohde & Schwarz (actually a Meinberg) ED170MP GPS Receiver
(and antenna) and I'd like to get it going.

Can someone here point me to the manual and any software for it?

 

Thanks!

 

Dave K2DH

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[time-nuts] Li-ion Battreries

[William H. Fite]

In the days prior to my recent retirement, when I was directing research at
a large VA Medical Center, one of our projects used inordinate quantities
of 18650 Li-ion batteries. We found in short order that buying from Amazon
or eBay was penny wise and pound foolish. Rather than flogging the internet
for deals, trying to save a few bucks, just buy Panasonic, Duracell, Sanyo,
Samsung Sony or LG directly from an authorized dealer.

As Chris pointed out, ammo boxes work are excellent for storage. We found
the manufacturer''s packaging perfectly adequate. They aren't bombs, guys.
Use sensible precautions and get on with it.


On Sunday, January 22, 2017, Chris Albertson > wrote:

> I'm using Lithium batteries too.   Button for everything.   For stationary
> lab bench use where AC mains is available and all I want is back up our the
> lead/acid gel cells work fine.  They are cheap, large and heavy and will
> take abuse and don't normally catch fire.
>
> For the mobile devices that I like to build nothing beats Lithium
> batteries.   I've been using the kind sold for use on remote controlled
> drone aircraft.   They have incredible power density and low cost.  Their
> biggest down side (an advantage to me) is their lack of consumer
> appropriate packaging.  The cells are only shrink wrapped and are easy to
> damage.  I change them with a programable "balanced" charger that is
> commonly used by hobbyists.
>
> I have found that YES you can start a fire from carelessly handing Lithium
> batteries.  You do have to understand how to use them and keep them
> packaged such that they remain safe even if they fail or (more likely) you
> make some mistake.   I keep them in fire proof glass fiber/silicone
> envelopes then inside a tightly close steel "ammo box". When in use
> they are installed in the mobil device I built in a metal compartment (I
> use those old fashion Japanese lunch boxes, they are like Tupperware but
> made completely of metal)
>
> Get these batteries at any of the Hobby supply outlets (NOT eBay, lots of
> fakes there.)
> Here is just one example of the last set I bought
> https://hobbyking.com/en_us/zippy-flightmax-4000mah-4s1p-20c.html
>
>
>
> On Sun, Jan 22, 2017 at 9:13 AM, Adrian Godwin 
> wrote:
>
> > Recovered cells aren't only sold through ebay parts adverts - they're
> also
> > used for production. I recently bought a few cell phone boosters which
> > consist of an 18650, a charge circuit and a voltage booster to 5V.
> >
> > They were low cost and nicely made with an extruded aluminium case and
> they
> > worked very well in my application. But on taking one apart, it was
> > apparent that they'd used a recovered cell.
> >
> > I've no complaints given the price, but be aware that the cell phone
> packs
> > may not be new either.
> >
> >
> > On Sun, Jan 22, 2017 at 4:48 PM, Didier Juges 
> wrote:
> >
> > > Well worth mentioning that you have found a reputable vendor. I may
> give
> > > them a try.
> > >
> > > A while back, I bought a dozen 18650 inexpensive(<$5 each) cells from 3
> > > vendors picked at semi-random on eBay (4 from each) for evaluation and
> I
> > > tested each one of them with a data logger.
> > > The best one had about half the advertised capacity, the others went
> down
> > > from there. Important to observe that none of the set I bought were
> even
> > > remotely matched, a crucial consideration if you are going to put them
> in
> > > series (a balancer will only ensure your pack is no better than the
> worst
> > > cell in the pack).
> > > Many of the 18650 cells you find on eBay (and maybe other places) are
> > > actually coming from old laptop battery packs that normally should have
> > > been discarded/recycled.
> > >
> > > In my anticipated application, I only needed one cell (to be followed
> by
> > a
> > > small boost converter), so the issue of balance and matched set was not
> > > important, but simply I needed the capacity and none were remotely
> > > satisfactory. I ended up using cell phone booster packs, since I needed
> > 5V
> > > anyway.
> > >
> > >
> > > On Sun, Jan 22, 2017 at 9:44 AM, Bert Kehren via time-nuts <
> > > time-nuts@febo.com> wrote:
> > >
> > > > I use 4 cell balancing and protection circuits, cost a couple of $
> more
> > > but
> > > >  well worth it, I use holders because of  limited availability of
> cells
> > > > with  straps, but rest assured they are held down (discarded PCB)'s,
> > > > I on purpose did not get into technical details I was only trying to
> > > share
> > > > reliable sources, based on disappointing past experiences.
> > > > Bert Kehren
> > > >
> > > >
> > > > In a message dated 1/22/2017 10:00:45 A.M. Eastern Standard Time,
> > > > att...@kinali.ch writes:
> > > >
> > > > Hoi  Bert,
> > > >
> > > > On Sat, 21 Jan 2017 08:08:22 -0500
> > > > Bert Kehren via time-nuts   wrote:

Re: [time-nuts] Li-ion Battreries

[Chris Albertson]

On Sun, Jan 22, 2017 at 9:36 AM, Mark Sims  wrote:

> I have a LOT of experience in testing and using 18650 cells.   It is a
> horrible place for the un-initiated to be.  The market is so saturated with
> dangerous fakes and inferior, over-speced cells that finding a genuine cell
> is a vanishingly small probability.  Hopefully the seller mentioned before
> pans out and sticks around.


I agree, many fakes.  But you CAN buy through reputable distributes like
Amazon.com  for maybe $16 per cell.

When I buy a battery packs the cells are already shrink wrapped and who
knows what is really inside, so I test the pack.  I charge it up and then
discharge it through a dummy load and track the power over time (actually
my programable charger can do this for me) then I recharge it ti to "stage
age voltage" and check that the self-discharge rate is reasonable.  I've
not had a problem with hobby type drone batteries and if I did I'd be
covered by even a 30 day warranty or failing that by PayPall's chargeback
policy.

I'd 100% recommend that anyone who buys a lithium battery place it inside a
fire proof enclosure then run it through a few charge/discharge cycles and
very the seller's specifications.   If you are not set up to do this kind
of acceptance testing don't buy lithium.

I can say first hand that once the lion battery fails, boiling electrolyte
and white smoke will continue to come out of the battery no batter what you
do, just take it outdoors and set it on the concrete and let it finish,
dropping the assembly in a bucket of water will not help, they will
generate a few hundred watts of heat until they run out of energy.  One
started it is a positive feedback loop.  But not dangerous if you thought
ahead to place the thing inside some metal container.  Just carry the
smoking mess outdoors and leave it there for a while.(I tried salvaging
lithium cells for Milwaukee power tools with only about 50% success rate)


-- 

Chris Albertson
Redondo Beach, California
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Re: [time-nuts] Li-ion Battreries

[Bert Kehren via time-nuts]

The reason I made the post is after bad experiences I found a vendor with  
genuine product and willingness to send you data sheets and my tests confirm 
 data within 3%. Can not ask for more. Can tell all the stories mentioned, 
been  there done it, that is why I felt it will be useful for time nuts. 
The Samsung data sheet is 752K otherwise I would attach. Claim 3350mA and  
100% at 0.2C that is what I tested and got 3327mA well with inn my test  
setup. 
 
Bert Kehren
 
 
In a message dated 1/22/2017 12:45:41 P.M. Eastern Standard Time,  
hol...@hotmail.com writes:

I have a  LOT of experience in testing and using 18650 cells.   It is a  
horrible place for the un-initiated to be.  The market is so saturated  with 
dangerous fakes and inferior, over-speced cells that finding a genuine  cell 
is a vanishingly small probability.  Hopefully the seller mentioned  before 
pans out and sticks around.

You can be pretty much assured that  any no-name Chinese cell will be 
dangerous crap.   Buy a 3000 mAh  cell that is really 500 mAh and charge it at 
the 3000 mAh 1C rate and  KERBLOOIE!   If you want to buy decent cells from a 
reputable maker  (Samsung, Sony, Panasonic, etc) you have to be certified 
that you know how to  properly build with and use them...  and also the 
minimum order quantity  can be over 100,000 pieces.

Shop around and you can find sellers of  18650 shrink wrap sleeves for all 
the major/reputable cells.   I  have yet to test a Chinese cell that comes 
even close to its advertised specs.  Also probably 90+% of what is offered as 
genuine name brand cells are  fakes.

Your best bet for finding a decent cell is to get them from  GENUINE laptop 
packs.  That is easier said than done...  counterfeit  packs are the norm.  
 Also, most newer laptops use packs with pouch  cells.  18650's are on the 
way out for modern  machines.
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Re: [time-nuts] Allan Variance with an HP53132a counter

[Magnus Danielson]

Hi,

There is two types of errors done when using this type of counters,

First, the delta-estimator of frequency filtering will skew the Allan 
deviation, mostly in the white phase noise region but the effect wears 
of at the length of the averaging windown of the counter. Correct 
interleave factor and processing lets the prefiltering be extended into 
modified Allan deviation.


Second, the moving average is a form of interleaved estimation producing 
a higher reading rate than the length of the avereage, giving a improved 
response compared to traditional non-interleaved behavior. However, 
processing such values as non-interleaved values will skew the Allan 
deviation response. Correctly handle it as interleaved values removes 
this bias effect.


You can do the same with Omega counters, considering you do things 
properly for PDEV. I've got a paper to complete on that topic.


Cheers,
Magnus

On 01/22/2017 03:52 PM, Gilles Clement wrote:

Hi,

I am new to this list and have been following it for a while with great interest. I am 
afraid I am getting contaminated with the "TN" virus… !

I developed a home-brewed OCXO crystal oscillator disciplined with a long wave 
radio station signal (162 kHz). Its working quite well with a long term 
stability that is « probably » better than 10E-8 which I am actually looking 
forward to better understand. I am considering using an HP53132 counter for 
this purpose, although I understand that it may not be the most recommended 
approach….

Please find hereafter the rationale:
- The HP53132 implements a triangular averaging algorithm (Delta averaging) in 
its standard frequency or period measurement mode of operation
- This feature provides a pretty high resolution (up to 0.5*10E-12 if I am 
correct) which should be appropriate at least to get a first idea of the 
oscillator performance
- But it comes with the drawback that an Allan Variance computed directly from such 
frequency (or period) readings, would be distorted with respect to the 
"standard" Allan Variance (which assumes a PI averaging instead of a Delta 
averaging algorithm to compute the fractional frequencies)
- However, from the Australian paper titled : « Considerations on the 
Measurement of the Stability of Oscillators with Frequency Counters » I noticed 
that:
When I look at OCXO crystals oscillator stability discussions in the 
literature, White Frequency, Flicker Frequency and Random Walk Frequency seem 
to be the dominant noise factors considered (ex: in phase noise spectral 
density graphics)
The distortion from Allan Variance to Delta Variance is limited for White 
Frequency, Flicker Frequency and Random Walk Frequency noises (though it can be 
several orders of magnitudes for White Phase and Flicker Phase noises)
Moreover formulas are provided in the paper to evaluate the amount of such 
distortions. The impact appears to be a simple multiplier of 1.33, 1.30 and 
1.15 for the three corresponding noises, the slopes of the curves are not 
impacted (i.e: tauE-1 ; tauE+0 and tauE+1)
- So the idea is the following: start with a simple bench test, reading the standard mode of 
Periods measurement, calculate the "naive" Triangular Variance from these data, 
identifying the noise types (according to the slope of the curve sections), and applying the 
corresponding offset correction, hopefully leading to an estimate of the "standard" Allan 
Variance.
- This approach would have the great advantage to be simple and cost effective, 
as one can find nowadays second hand 53132’s at reasonable cost even with the 
(mandatory) OCXO option.

Comments welcomed,
Best,
Gilles.
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Re: [time-nuts] purpose of time of day display units

[Chris Albertson]

I used to work at a place that used a lot of those LED time displays that
were hooked up to IRIG.   Why were they there?  Because everyone hates to
toss out nice working equipment.  The displays were bought ages ago and
still work just fine. Many of those racks you see were assembled 15 or
more years ago.

Today my cell phone has a time display that is just as accurate as a GPS
controlled LED display because the bottle neck for displays is human
perception, We just can't see better than about 1/20th of a second.

Sometimes however we'd run the equipment with the time of day not set to
the actual time of day, say for re-playing historic data.  THEN the display
is nice to have if for nothing else to verify the setup is working and you
are in fact sync's up to recored IRIG from some 20 year old database or
even tape.But even for real time, the display verifies the system is
running.  If it matches your iPhone then all is good.

In short the best use of these displays is confidence that things are
working.  Because you know they display is driven by IRIRG and not by a
realtime clock, so if you are getting IRIG data, you are up and running to
at least some degree.



On Sat, Jan 21, 2017 at 10:31 PM, Ruslan Nabioullin 
wrote:

> Hi, looking at pictures of various time metrology equipment setups for
> best practices and inspiration, I have commonly seen time of day display
> unit(s) installed in racks containing processing or time transfer
> equipment, e.g., http://www.xyht.com/wp-content/uploads/2015/05/Powers_
> Master_Clock.jpg. All that these units do is merely display the time of
> day and sometimes the date, typically by means of seven segment LED
> displays, of the time code inputted to them (typically IRIG-B, I'm
> guessing).  Any ideas why such a unit is necessary when one can simply look
> at the time displayed by timing receivers and time code generators (and
> even some standards), and the interface of some fusor, defined in this
> context as a system which performs timing data fusion (by implementing a
> paper clock or a more primitive algorithm) and timekeeping, either by means
> of a direct shell, or via something like NTP?
>
> Thanks in advance,
> Ruslan
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>



-- 

Chris Albertson
Redondo Beach, California
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Re: [time-nuts] Li-ion Battreries

[Chris Albertson]

I'm using Lithium batteries too.   Button for everything.   For stationary
lab bench use where AC mains is available and all I want is back up our the
lead/acid gel cells work fine.  They are cheap, large and heavy and will
take abuse and don't normally catch fire.

For the mobile devices that I like to build nothing beats Lithium
batteries.   I've been using the kind sold for use on remote controlled
drone aircraft.   They have incredible power density and low cost.  Their
biggest down side (an advantage to me) is their lack of consumer
appropriate packaging.  The cells are only shrink wrapped and are easy to
damage.  I change them with a programable "balanced" charger that is
commonly used by hobbyists.

I have found that YES you can start a fire from carelessly handing Lithium
batteries.  You do have to understand how to use them and keep them
packaged such that they remain safe even if they fail or (more likely) you
make some mistake.   I keep them in fire proof glass fiber/silicone
envelopes then inside a tightly close steel "ammo box". When in use
they are installed in the mobil device I built in a metal compartment (I
use those old fashion Japanese lunch boxes, they are like Tupperware but
made completely of metal)

Get these batteries at any of the Hobby supply outlets (NOT eBay, lots of
fakes there.)
Here is just one example of the last set I bought
https://hobbyking.com/en_us/zippy-flightmax-4000mah-4s1p-20c.html



On Sun, Jan 22, 2017 at 9:13 AM, Adrian Godwin  wrote:

> Recovered cells aren't only sold through ebay parts adverts - they're also
> used for production. I recently bought a few cell phone boosters which
> consist of an 18650, a charge circuit and a voltage booster to 5V.
>
> They were low cost and nicely made with an extruded aluminium case and they
> worked very well in my application. But on taking one apart, it was
> apparent that they'd used a recovered cell.
>
> I've no complaints given the price, but be aware that the cell phone packs
> may not be new either.
>
>
> On Sun, Jan 22, 2017 at 4:48 PM, Didier Juges  wrote:
>
> > Well worth mentioning that you have found a reputable vendor. I may give
> > them a try.
> >
> > A while back, I bought a dozen 18650 inexpensive(<$5 each) cells from 3
> > vendors picked at semi-random on eBay (4 from each) for evaluation and I
> > tested each one of them with a data logger.
> > The best one had about half the advertised capacity, the others went down
> > from there. Important to observe that none of the set I bought were even
> > remotely matched, a crucial consideration if you are going to put them in
> > series (a balancer will only ensure your pack is no better than the worst
> > cell in the pack).
> > Many of the 18650 cells you find on eBay (and maybe other places) are
> > actually coming from old laptop battery packs that normally should have
> > been discarded/recycled.
> >
> > In my anticipated application, I only needed one cell (to be followed by
> a
> > small boost converter), so the issue of balance and matched set was not
> > important, but simply I needed the capacity and none were remotely
> > satisfactory. I ended up using cell phone booster packs, since I needed
> 5V
> > anyway.
> >
> >
> > On Sun, Jan 22, 2017 at 9:44 AM, Bert Kehren via time-nuts <
> > time-nuts@febo.com> wrote:
> >
> > > I use 4 cell balancing and protection circuits, cost a couple of $ more
> > but
> > >  well worth it, I use holders because of  limited availability of cells
> > > with  straps, but rest assured they are held down (discarded PCB)'s,
> > > I on purpose did not get into technical details I was only trying to
> > share
> > > reliable sources, based on disappointing past experiences.
> > > Bert Kehren
> > >
> > >
> > > In a message dated 1/22/2017 10:00:45 A.M. Eastern Standard Time,
> > > att...@kinali.ch writes:
> > >
> > > Hoi  Bert,
> > >
> > > On Sat, 21 Jan 2017 08:08:22 -0500
> > > Bert Kehren via time-nuts   wrote:
> > >
> > > > purchased  _2x   Samsung 35E 3500mAh 10A 18650 High Drain
> Rechargeable
> > > Battery
> > > >  INR18650-35E_
> > > >
> > > (http://www.ebay.com/itm/112173495496?_trksid=p2060353.
> > > m2749.l2649=STRK:MEBIDX:IT)   for two reason 10 A load  and
> > > good price. These
> > > > cells have no  protection, which I want, since I will for  our
> > > applications
> > > > stack 4 with a 4  cell controller and in two application also
> parallel
> > > cells
> > > > for a total of  8.  I have now completed my  tests  and concentrate
> my
> > > > battery work on using these   cells.
> > > > After having tested 26650 cells with disappointing   results my focus
> > is
> > > on
> > > > 18650. I am sure there will be 26650 cells  available, but  right now
> > our
> > > > focus is on 18650.
> > > > I have  no connection in any way with these two sources,  but think
> it
> > > may
> > > > be helpful for those that look for batteris and do not want to   go
> 

[time-nuts] Torpey Controls/Torpey Time CLK-5 Master Clock manual or schematic.

[Merchison Burke via time-nuts]

Hello all,

I'm looking for a manual with schematics or at least an electronic copy 
of the schematics.


Thank you,

Merchison

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Re: [time-nuts] Li-ion Battreries

[Chuck Harris]

One of my hats is working with a recycler to help them
best utilize their input stream of recycled electronics.

To that end, I take a lot of things apart, looking for
failure mechanisms.  This allows me to discover common
problems, and to suggest which items are economical to
repair, and which aren't.  In the course of that activity,
I have observed a lot of failed lithium battery packs.

The most common failure is due to the pack being allowed
to discharge too deeply.  The protection electronics is happy
to disconnect individual cells when they have reached a
safe lowest voltage, which is good, but it doesn't do a very
good job of protecting cells that are then left for weeks,
months, or years in that discharged state.

Eventually the cells self discharge (fueled by the protection
circuitry's monitoring circuits) to a point where the
protection circuitry won't allow them to be charged anymore.

If you catch the packs quickly enough, you can bypass the
protection circuitry, and pump some charge directly into the
cells to restore function.

If you wait too long before restoring the cell, they will
often get hot, swell up, catch fire, and sometimes explode.

They will also do this if you physically abuse the cells by
denting them, heating them too hot, or bending them too far.

You have been warned!

Once you have a cell that functions properly, but maybe
at a reduced capacity, it will continue to work reliably,
and will continue to slowly lose capacity, just as a new
cell would.

-Chuck Harris

Adrian Godwin wrote:
> Recovered cells aren't only sold through ebay parts adverts - they're also
> used for production. I recently bought a few cell phone boosters which
> consist of an 18650, a charge circuit and a voltage booster to 5V.
> 
> They were low cost and nicely made with an extruded aluminium case and they
> worked very well in my application. But on taking one apart, it was
> apparent that they'd used a recovered cell.
> 
> I've no complaints given the price, but be aware that the cell phone packs
> may not be new either.
> 
> 
> On Sun, Jan 22, 2017 at 4:48 PM, Didier Juges  wrote:
> 
>> Well worth mentioning that you have found a reputable vendor. I may give
>> them a try.
>>
>> A while back, I bought a dozen 18650 inexpensive(<$5 each) cells from 3
>> vendors picked at semi-random on eBay (4 from each) for evaluation and I
>> tested each one of them with a data logger.
>> The best one had about half the advertised capacity, the others went down
>> from there. Important to observe that none of the set I bought were even
>> remotely matched, a crucial consideration if you are going to put them in
>> series (a balancer will only ensure your pack is no better than the worst
>> cell in the pack).
>> Many of the 18650 cells you find on eBay (and maybe other places) are
>> actually coming from old laptop battery packs that normally should have
>> been discarded/recycled.
>>
>> In my anticipated application, I only needed one cell (to be followed by a
>> small boost converter), so the issue of balance and matched set was not
>> important, but simply I needed the capacity and none were remotely
>> satisfactory. I ended up using cell phone booster packs, since I needed 5V
>> anyway.
>>
>>
>> On Sun, Jan 22, 2017 at 9:44 AM, Bert Kehren via time-nuts <
>> time-nuts@febo.com> wrote:
>>
>>> I use 4 cell balancing and protection circuits, cost a couple of $ more
>> but
>>>  well worth it, I use holders because of  limited availability of cells
>>> with  straps, but rest assured they are held down (discarded PCB)'s,
>>> I on purpose did not get into technical details I was only trying to
>> share
>>> reliable sources, based on disappointing past experiences.
>>> Bert Kehren
>>>
>>>
>>> In a message dated 1/22/2017 10:00:45 A.M. Eastern Standard Time,
>>> att...@kinali.ch writes:
>>>
>>> Hoi  Bert,
>>>
>>> On Sat, 21 Jan 2017 08:08:22 -0500
>>> Bert Kehren via time-nuts   wrote:
>>>
 purchased  _2x   Samsung 35E 3500mAh 10A 18650 High Drain Rechargeable
>>> Battery
  INR18650-35E_

>>> (http://www.ebay.com/itm/112173495496?_trksid=p2060353.
>>> m2749.l2649=STRK:MEBIDX:IT)   for two reason 10 A load  and
>>> good price. These
 cells have no  protection, which I want, since I will for  our
>>> applications
 stack 4 with a 4  cell controller and in two application also  parallel
>>> cells
 for a total of  8.  I have now completed my  tests  and concentrate my
 battery work on using these   cells.
 After having tested 26650 cells with disappointing   results my focus
>> is
>>> on
 18650. I am sure there will be 26650 cells  available, but  right now
>> our
 focus is on 18650.
 I have  no connection in any way with these two sources,  but think it
>>> may
 be helpful for those that look for batteris and do not want to   go
>>> through
 the process I went through.
>>>
>>>
>>> Some  small remarks: 18650 is by far the most common 

Re: [time-nuts] purpose of time of day display units

[Bob Bownes]

#5) Everyone likes blinkenlights. 



> On Jan 22, 2017, at 08:55, jimlux  wrote:
> 
>> On 1/21/17 10:31 PM, Ruslan Nabioullin wrote:
>> Hi, looking at pictures of various time metrology equipment setups for
>> best practices and inspiration, I have commonly seen time of day display
>> unit(s) installed in racks containing processing or time transfer
>> equipment, e.g.,
>> http://www.xyht.com/wp-content/uploads/2015/05/Powers_Master_Clock.jpg.
>> All that these units do is merely display the time of day and sometimes
>> the date, typically by means of seven segment LED displays, of the time
>> code inputted to them (typically IRIG-B, I'm guessing).
> 
> There's a few reasons I can think of:
> 1) the display is also a distribution amplifier of some sort - one time 
> source going into rack, distributed to things in the rack (or the next rack)
> 
> 2) as phk commented, it lets you know that your time code isn't broken (i.e. 
> someone got in behind the rack and disconnected the wrong cable)
> 
> 3) It's a crude visual check - your eye/brain is pretty good at catching a 
> change in the pattern of blinky lights.  IN this situation, you'd expect all 
> the displays to change simultaneously.
> 
> 4) the equipment configuration "just growed" from a collection of smaller 
> ones, each with its own display.
> 
> We put displays like this in all of our ground support equipment (GSE) racks 
> when doing spacecraft or subsystem tests, mostly for reason #2 and #4.
> 
> You might have a GSE rack or two in the lab when you're building up the 
> subsystem.  Someone else's subsystem has their rack, also with a timecode 
> display.   When you bring the two subsystems together for integration, you 
> bring the racks with them, and it's not worth it to reconfigure.
> 
> 
> 
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[time-nuts] Li-ion Battreries

[Mark Sims]

I have a LOT of experience in testing and using 18650 cells.   It is a horrible 
place for the un-initiated to be.  The market is so saturated with dangerous 
fakes and inferior, over-speced cells that finding a genuine cell is a 
vanishingly small probability.  Hopefully the seller mentioned before pans out 
and sticks around.

You can be pretty much assured that any no-name Chinese cell will be dangerous 
crap.   Buy a 3000 mAh cell that is really 500 mAh and charge it at the 3000 
mAh 1C rate and KERBLOOIE!   If you want to buy decent cells from a reputable 
maker (Samsung, Sony, Panasonic, etc) you have to be certified that you know 
how to properly build with and use them...  and also the minimum order quantity 
can be over 100,000 pieces.

Shop around and you can find sellers of 18650 shrink wrap sleeves for all the 
major/reputable cells.   I have yet to test a Chinese cell that comes even 
close to its advertised specs. Also probably 90+% of what is offered as genuine 
name brand cells are fakes.

Your best bet for finding a decent cell is to get them from GENUINE laptop 
packs.  That is easier said than done...  counterfeit packs are the norm.   
Also, most newer laptops use packs with pouch cells.  18650's are on the way 
out for modern machines.
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Re: [time-nuts] Li-ion Battreries

[Adrian Godwin]

Recovered cells aren't only sold through ebay parts adverts - they're also
used for production. I recently bought a few cell phone boosters which
consist of an 18650, a charge circuit and a voltage booster to 5V.

They were low cost and nicely made with an extruded aluminium case and they
worked very well in my application. But on taking one apart, it was
apparent that they'd used a recovered cell.

I've no complaints given the price, but be aware that the cell phone packs
may not be new either.


On Sun, Jan 22, 2017 at 4:48 PM, Didier Juges  wrote:

> Well worth mentioning that you have found a reputable vendor. I may give
> them a try.
>
> A while back, I bought a dozen 18650 inexpensive(<$5 each) cells from 3
> vendors picked at semi-random on eBay (4 from each) for evaluation and I
> tested each one of them with a data logger.
> The best one had about half the advertised capacity, the others went down
> from there. Important to observe that none of the set I bought were even
> remotely matched, a crucial consideration if you are going to put them in
> series (a balancer will only ensure your pack is no better than the worst
> cell in the pack).
> Many of the 18650 cells you find on eBay (and maybe other places) are
> actually coming from old laptop battery packs that normally should have
> been discarded/recycled.
>
> In my anticipated application, I only needed one cell (to be followed by a
> small boost converter), so the issue of balance and matched set was not
> important, but simply I needed the capacity and none were remotely
> satisfactory. I ended up using cell phone booster packs, since I needed 5V
> anyway.
>
>
> On Sun, Jan 22, 2017 at 9:44 AM, Bert Kehren via time-nuts <
> time-nuts@febo.com> wrote:
>
> > I use 4 cell balancing and protection circuits, cost a couple of $ more
> but
> >  well worth it, I use holders because of  limited availability of cells
> > with  straps, but rest assured they are held down (discarded PCB)'s,
> > I on purpose did not get into technical details I was only trying to
> share
> > reliable sources, based on disappointing past experiences.
> > Bert Kehren
> >
> >
> > In a message dated 1/22/2017 10:00:45 A.M. Eastern Standard Time,
> > att...@kinali.ch writes:
> >
> > Hoi  Bert,
> >
> > On Sat, 21 Jan 2017 08:08:22 -0500
> > Bert Kehren via time-nuts   wrote:
> >
> > > purchased  _2x   Samsung 35E 3500mAh 10A 18650 High Drain Rechargeable
> > Battery
> > >  INR18650-35E_
> > >
> > (http://www.ebay.com/itm/112173495496?_trksid=p2060353.
> > m2749.l2649=STRK:MEBIDX:IT)   for two reason 10 A load  and
> > good price. These
> > > cells have no  protection, which I want, since I will for  our
> > applications
> > > stack 4 with a 4  cell controller and in two application also  parallel
> > cells
> > > for a total of  8.  I have now completed my  tests  and concentrate my
> > > battery work on using these   cells.
> > > After having tested 26650 cells with disappointing   results my focus
> is
> > on
> > > 18650. I am sure there will be 26650 cells  available, but  right now
> our
> > > focus is on 18650.
> > > I have  no connection in any way with these two sources,  but think it
> > may
> > > be helpful for those that look for batteris and do not want to   go
> > through
> > > the process I went through.
> >
> >
> > Some  small remarks: 18650 is by far the most common form factor
> > of Li-Ion  batteries on the market. This is IMHO the better choice
> > than the 26650 if  you want to be able to replace them in 10-20 years.
> >
> > If you stack Li-*  batteries, you will need to have a controller that
> > monitors each cell  individually while charging or has some other means
> > of ensuring that none  of the cells are overcharged (or rather that they
> > are charged the same  amount). This kind of circuit is called balancer.
> > A protection circuit does  _not_ replace a balancer. The protection
> circuit
> > is only to protect against  catastrophic failure. Ie it is still possible
> > to overcharge a battery even  if it has a protection circuit. You also do
> > not know what the protection  circuit does to protect the cell. There are
> > a lot of chips out there, that  simply open a switch and thus disconnect
> > the cell. In this case, the  protection circuit of one cell will
> disconnect
> > the whole stack and break  charging.
> >
> > A lot of the multi-cell Li-Ion charger chips have integrated  cell
> > protection
> > circuitry. Ie if you use one of them, you will not need an  additional
> > protection circuit. But be aware, the regulation for battery  protection
> > circuit states that the circuit has to be wired fix onto the  battery
> > in a way that this connection cannot be broken (without breaking  the
> > housing of the battery pack). The reason for this is, i think,  pretty
> > obvious. I would recommend that you solder each cell  indidividually
> > into your circuit instead of using some kind of holder. Or  if 

Re: [time-nuts] Allan Variance with an HP53132a counter

[Azelio Boriani]

You don't need the OCXO option for the 53132... you need a stable and
accurate source like a GPSDO that will be your reference. Consider
buying the HP53132 but also a GPSDO. Is the 162kHz transmitter the
Allouis one (TDF/Syrte)?

On Sun, Jan 22, 2017 at 3:52 PM, Gilles Clement
 wrote:
> Hi,
>
> I am new to this list and have been following it for a while with great 
> interest. I am afraid I am getting contaminated with the "TN" virus… !
>
> I developed a home-brewed OCXO crystal oscillator disciplined with a long 
> wave radio station signal (162 kHz). Its working quite well with a long term 
> stability that is « probably » better than 10E-8 which I am actually looking 
> forward to better understand. I am considering using an HP53132 counter for 
> this purpose, although I understand that it may not be the most recommended 
> approach….
>
> Please find hereafter the rationale:
> - The HP53132 implements a triangular averaging algorithm (Delta averaging) 
> in its standard frequency or period measurement mode of operation
> - This feature provides a pretty high resolution (up to 0.5*10E-12 if I am 
> correct) which should be appropriate at least to get a first idea of the 
> oscillator performance
> - But it comes with the drawback that an Allan Variance computed directly 
> from such frequency (or period) readings, would be distorted with respect to 
> the "standard" Allan Variance (which assumes a PI averaging instead of a 
> Delta averaging algorithm to compute the fractional frequencies)
> - However, from the Australian paper titled : « Considerations on the 
> Measurement of the Stability of Oscillators with Frequency Counters » I 
> noticed that:
> When I look at OCXO crystals oscillator stability discussions in the 
> literature, White Frequency, Flicker Frequency and Random Walk Frequency seem 
> to be the dominant noise factors considered (ex: in phase noise spectral 
> density graphics)
> The distortion from Allan Variance to Delta Variance is limited for White 
> Frequency, Flicker Frequency and Random Walk Frequency noises (though it can 
> be several orders of magnitudes for White Phase and Flicker Phase noises)
> Moreover formulas are provided in the paper to evaluate the amount of such 
> distortions. The impact appears to be a simple multiplier of 1.33, 1.30 and 
> 1.15 for the three corresponding noises, the slopes of the curves are not 
> impacted (i.e: tauE-1 ; tauE+0 and tauE+1)
> - So the idea is the following: start with a simple bench test, reading the 
> standard mode of Periods measurement, calculate the "naive" Triangular 
> Variance from these data, identifying the noise types (according to the slope 
> of the curve sections), and applying the corresponding offset correction, 
> hopefully leading to an estimate of the "standard" Allan Variance.
> - This approach would have the great advantage to be simple and cost 
> effective, as one can find nowadays second hand 53132’s at reasonable cost 
> even with the (mandatory) OCXO option.
>
> Comments welcomed,
> Best,
> Gilles.
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Re: [time-nuts] Li-ion Battreries

[Didier Juges]

Well worth mentioning that you have found a reputable vendor. I may give
them a try.

A while back, I bought a dozen 18650 inexpensive(<$5 each) cells from 3
vendors picked at semi-random on eBay (4 from each) for evaluation and I
tested each one of them with a data logger.
The best one had about half the advertised capacity, the others went down
from there. Important to observe that none of the set I bought were even
remotely matched, a crucial consideration if you are going to put them in
series (a balancer will only ensure your pack is no better than the worst
cell in the pack).
Many of the 18650 cells you find on eBay (and maybe other places) are
actually coming from old laptop battery packs that normally should have
been discarded/recycled.

In my anticipated application, I only needed one cell (to be followed by a
small boost converter), so the issue of balance and matched set was not
important, but simply I needed the capacity and none were remotely
satisfactory. I ended up using cell phone booster packs, since I needed 5V
anyway.


On Sun, Jan 22, 2017 at 9:44 AM, Bert Kehren via time-nuts <
time-nuts@febo.com> wrote:

> I use 4 cell balancing and protection circuits, cost a couple of $ more but
>  well worth it, I use holders because of  limited availability of cells
> with  straps, but rest assured they are held down (discarded PCB)'s,
> I on purpose did not get into technical details I was only trying to share
> reliable sources, based on disappointing past experiences.
> Bert Kehren
>
>
> In a message dated 1/22/2017 10:00:45 A.M. Eastern Standard Time,
> att...@kinali.ch writes:
>
> Hoi  Bert,
>
> On Sat, 21 Jan 2017 08:08:22 -0500
> Bert Kehren via time-nuts   wrote:
>
> > purchased  _2x   Samsung 35E 3500mAh 10A 18650 High Drain Rechargeable
> Battery
> >  INR18650-35E_
> >
> (http://www.ebay.com/itm/112173495496?_trksid=p2060353.
> m2749.l2649=STRK:MEBIDX:IT)   for two reason 10 A load  and
> good price. These
> > cells have no  protection, which I want, since I will for  our
> applications
> > stack 4 with a 4  cell controller and in two application also  parallel
> cells
> > for a total of  8.  I have now completed my  tests  and concentrate my
> > battery work on using these   cells.
> > After having tested 26650 cells with disappointing   results my focus is
> on
> > 18650. I am sure there will be 26650 cells  available, but  right now our
> > focus is on 18650.
> > I have  no connection in any way with these two sources,  but think it
> may
> > be helpful for those that look for batteris and do not want to   go
> through
> > the process I went through.
>
>
> Some  small remarks: 18650 is by far the most common form factor
> of Li-Ion  batteries on the market. This is IMHO the better choice
> than the 26650 if  you want to be able to replace them in 10-20 years.
>
> If you stack Li-*  batteries, you will need to have a controller that
> monitors each cell  individually while charging or has some other means
> of ensuring that none  of the cells are overcharged (or rather that they
> are charged the same  amount). This kind of circuit is called balancer.
> A protection circuit does  _not_ replace a balancer. The protection circuit
> is only to protect against  catastrophic failure. Ie it is still possible
> to overcharge a battery even  if it has a protection circuit. You also do
> not know what the protection  circuit does to protect the cell. There are
> a lot of chips out there, that  simply open a switch and thus disconnect
> the cell. In this case, the  protection circuit of one cell will disconnect
> the whole stack and break  charging.
>
> A lot of the multi-cell Li-Ion charger chips have integrated  cell
> protection
> circuitry. Ie if you use one of them, you will not need an  additional
> protection circuit. But be aware, the regulation for battery  protection
> circuit states that the circuit has to be wired fix onto the  battery
> in a way that this connection cannot be broken (without breaking  the
> housing of the battery pack). The reason for this is, i think,  pretty
> obvious. I would recommend that you solder each cell  indidividually
> into your circuit instead of using some kind of holder. Or  if you are
> using a holder, make it such that there is no chance any of the  cells
> can be accidentally short circuited.
>
> Attila Kinali
> --
> Malek's Law:
> Any simple idea will be worded in the most complicated  way.
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>
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To 

Re: [time-nuts] Li-ion Battreries

[Chuck Harris]

Just a quiet message that needs to be said:

18650 style LiIon cells are indeed one of the most common
styles of LiIon cells, but with their popularity comes a
great deal of fraudulent sales activity.

The 18650 cells are used in all sorts of trendy gadgets, like
the vape appliences for niccotine addicts, over powered green
laser pointers, and vibrators for... well... urhmm...ahhh, I can't
say.

I went on a quest to try to buy 18650 cells for cheap prices,
and then tested them on my Christie CASP battery charger/tester,
and I found that I could buy the things wrapped with the labels
of Samsung, Sanyo, UltraFire, PowerSonic, and probably a dozen
other brands, labeled with 3000 through 9800mAH capacities.

In testing, I found two things.  If the batteries came from
eBay, or Amazon, they would weigh between 1/3 and 1/2 as much
as the manufacturer's spec sheets said they would, and they
would test at between 400 and 500mAH.  And that was with allowing
them to discharge until their internal protection circuitry
shut them down... in other words to an unsafe level.

So, the moral of my story is know your sources, and do test
every one... a twist on the old saying: Don't trust but verify.

I quit the project, as I feared that the high number of items
I was declaring as counterfeit for refund, would soon catch up
with me and render me unfit for ebay and Amazon purchases.

The safest, surest supply I have found is discarded laptop
batteries for Dell computers.  Bust them apart, and you will
find that all but one of the cells is in good condition.  The
one bad cell can almost always be resurrected by charging it
manually to 4.2V at less than 1C current.

Note, they won't have the protection circuitry installed as part
of the cell, but you can buy that part on eBay with pretty good
results..

-Chuck Harris

Attila Kinali wrote:
> Hoi Bert,
> Some small remarks: 18650 is by far the most common form factor
> of Li-Ion batteries on the market. This is IMHO the better choice
> than the 26650 if you want to be able to replace them in 10-20 years.
> 
> If you stack Li-* batteries, you will need to have a controller that
> monitors each cell individually while charging or has some other means
> of ensuring that none of the cells are overcharged (or rather that they
> are charged the same amount). This kind of circuit is called balancer.
> A protection circuit does _not_ replace a balancer. The protection circuit
> is only to protect against catastrophic failure. Ie it is still possible
> to overcharge a battery even if it has a protection circuit. You also do
> not know what the protection circuit does to protect the cell. There are
> a lot of chips out there, that simply open a switch and thus disconnect
> the cell. In this case, the protection circuit of one cell will disconnect
> the whole stack and break charging.
> 
> A lot of the multi-cell Li-Ion charger chips have integrated cell protection
> circuitry. Ie if you use one of them, you will not need an additional
> protection circuit. But be aware, the regulation for battery protection
> circuit states that the circuit has to be wired fix onto the battery
> in a way that this connection cannot be broken (without breaking the
> housing of the battery pack). The reason for this is, i think, pretty
> obvious. I would recommend that you solder each cell indidividually
> into your circuit instead of using some kind of holder. Or if you are
> using a holder, make it such that there is no chance any of the cells
> can be accidentally short circuited.
> 
>   Attila Kinali
> 
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Re: [time-nuts] OT: Eagle PC CAD now Autodesk, $500/year

[John Ackermann N8UR]

The .INF file seems just to be a text description, and the non-versioned 
.ext/.zip/.run file  file is a link to the file one with the version number.  
So either one will get you the same installer, and the .INF file isn't needed.

Sent from BlueMail ​

On Jan 21, 2017, 9:45 PM, at 9:45 PM, "Richard (Rick) Karlquist" 
 wrote:
>I downloaded the following:
>
>eagle-win64.exe
>eagle-win64-7.7.0.exe
>eagle-win64-7.7.0.exe.INF
>
>What is the difference between these files in terms of installing this 
>version?  Which file do I run?  Do I need the other ones to go along
>with it?
>
>(Similarly, for LINUX, there is the same set of files, except
>substitute "run" for "exe")
>
>Rick N6RK
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[time-nuts] Allan Variance with an HP53132a counter

[Gilles Clement]

Hi, 

I am new to this list and have been following it for a while with great 
interest. I am afraid I am getting contaminated with the "TN" virus… !

I developed a home-brewed OCXO crystal oscillator disciplined with a long wave 
radio station signal (162 kHz). Its working quite well with a long term 
stability that is « probably » better than 10E-8 which I am actually looking 
forward to better understand. I am considering using an HP53132 counter for 
this purpose, although I understand that it may not be the most recommended 
approach….

Please find hereafter the rationale: 
- The HP53132 implements a triangular averaging algorithm (Delta averaging) in 
its standard frequency or period measurement mode of operation 
- This feature provides a pretty high resolution (up to 0.5*10E-12 if I am 
correct) which should be appropriate at least to get a first idea of the 
oscillator performance
- But it comes with the drawback that an Allan Variance computed directly from 
such frequency (or period) readings, would be distorted with respect to the 
"standard" Allan Variance (which assumes a PI averaging instead of a Delta 
averaging algorithm to compute the fractional frequencies)
- However, from the Australian paper titled : « Considerations on the 
Measurement of the Stability of Oscillators with Frequency Counters » I noticed 
that:
When I look at OCXO crystals oscillator stability discussions in the 
literature, White Frequency, Flicker Frequency and Random Walk Frequency seem 
to be the dominant noise factors considered (ex: in phase noise spectral 
density graphics)
The distortion from Allan Variance to Delta Variance is limited for White 
Frequency, Flicker Frequency and Random Walk Frequency noises (though it can be 
several orders of magnitudes for White Phase and Flicker Phase noises)
Moreover formulas are provided in the paper to evaluate the amount of such 
distortions. The impact appears to be a simple multiplier of 1.33, 1.30 and 
1.15 for the three corresponding noises, the slopes of the curves are not 
impacted (i.e: tauE-1 ; tauE+0 and tauE+1)
- So the idea is the following: start with a simple bench test, reading the 
standard mode of Periods measurement, calculate the "naive" Triangular Variance 
from these data, identifying the noise types (according to the slope of the 
curve sections), and applying the corresponding offset correction, hopefully 
leading to an estimate of the "standard" Allan Variance.  
- This approach would have the great advantage to be simple and cost effective, 
as one can find nowadays second hand 53132’s at reasonable cost even with the 
(mandatory) OCXO option.  

Comments welcomed, 
Best, 
Gilles. 
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Re: [time-nuts] Li-ion Battreries

[Bert Kehren via time-nuts]

I use 4 cell balancing and protection circuits, cost a couple of $ more but 
 well worth it, I use holders because of  limited availability of cells 
with  straps, but rest assured they are held down (discarded PCB)'s,
I on purpose did not get into technical details I was only trying to share  
reliable sources, based on disappointing past experiences.
Bert Kehren
 
 
In a message dated 1/22/2017 10:00:45 A.M. Eastern Standard Time,  
att...@kinali.ch writes:

Hoi  Bert,

On Sat, 21 Jan 2017 08:08:22 -0500
Bert Kehren via time-nuts   wrote:

> purchased  _2x   Samsung 35E 3500mAh 10A 18650 High Drain Rechargeable 
Battery  
>  INR18650-35E_ 
>  
(http://www.ebay.com/itm/112173495496?_trksid=p2060353.m2749.l2649=STRK:MEBIDX:IT)
   for two reason 10 A load  and good price. These 
> cells have no  protection, which I want, since I will for  our 
applications   
> stack 4 with a 4  cell controller and in two application also  parallel 
cells 
> for a total of  8.  I have now completed my  tests  and concentrate my 
> battery work on using these   cells. 
> After having tested 26650 cells with disappointing   results my focus is 
on 
> 18650. I am sure there will be 26650 cells  available, but  right now our 
> focus is on 18650. 
> I have  no connection in any way with these two sources,  but think it 
may  
> be helpful for those that look for batteris and do not want to   go 
through 
> the process I went through.   


Some  small remarks: 18650 is by far the most common form factor
of Li-Ion  batteries on the market. This is IMHO the better choice
than the 26650 if  you want to be able to replace them in 10-20 years.

If you stack Li-*  batteries, you will need to have a controller that
monitors each cell  individually while charging or has some other means
of ensuring that none  of the cells are overcharged (or rather that they
are charged the same  amount). This kind of circuit is called balancer.
A protection circuit does  _not_ replace a balancer. The protection circuit
is only to protect against  catastrophic failure. Ie it is still possible
to overcharge a battery even  if it has a protection circuit. You also do
not know what the protection  circuit does to protect the cell. There are
a lot of chips out there, that  simply open a switch and thus disconnect
the cell. In this case, the  protection circuit of one cell will disconnect
the whole stack and break  charging.

A lot of the multi-cell Li-Ion charger chips have integrated  cell 
protection
circuitry. Ie if you use one of them, you will not need an  additional
protection circuit. But be aware, the regulation for battery  protection
circuit states that the circuit has to be wired fix onto the  battery
in a way that this connection cannot be broken (without breaking  the
housing of the battery pack). The reason for this is, i think,  pretty
obvious. I would recommend that you solder each cell  indidividually
into your circuit instead of using some kind of holder. Or  if you are
using a holder, make it such that there is no chance any of the  cells
can be accidentally short circuited.

Attila Kinali
-- 
Malek's Law:
Any simple idea will be worded in the most complicated  way.
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Re: [time-nuts] purpose of time of day display units

[jimlux]

On 1/21/17 10:31 PM, Ruslan Nabioullin wrote:

Hi, looking at pictures of various time metrology equipment setups for
best practices and inspiration, I have commonly seen time of day display
unit(s) installed in racks containing processing or time transfer
equipment, e.g.,
http://www.xyht.com/wp-content/uploads/2015/05/Powers_Master_Clock.jpg.
All that these units do is merely display the time of day and sometimes
the date, typically by means of seven segment LED displays, of the time
code inputted to them (typically IRIG-B, I'm guessing).


There's a few reasons I can think of:
1) the display is also a distribution amplifier of some sort - one time 
source going into rack, distributed to things in the rack (or the next rack)


2) as phk commented, it lets you know that your time code isn't broken 
(i.e. someone got in behind the rack and disconnected the wrong cable)


3) It's a crude visual check - your eye/brain is pretty good at catching 
a change in the pattern of blinky lights.  IN this situation, you'd 
expect all the displays to change simultaneously.


4) the equipment configuration "just growed" from a collection of 
smaller ones, each with its own display.


We put displays like this in all of our ground support equipment (GSE) 
racks when doing spacecraft or subsystem tests, mostly for reason #2 and #4.


You might have a GSE rack or two in the lab when you're building up the 
subsystem.  Someone else's subsystem has their rack, also with a 
timecode display.   When you bring the two subsystems together for 
integration, you bring the racks with them, and it's not worth it to 
reconfigure.




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Re: [time-nuts] purpose of time of day display units

[Tim Shoppa]

The big clocks on the walls of the control center were largely eye-candy
for visitors, but the individual clocks at each console were continuously
used by the operators for everything (there was no computer display of
time). All important technical timing was run from dedicated sequencers but
it might be "kicked off" from IRIG-derived pulses on some occasions (in my
experience it might be spec'ed to be kicked off from IRIG but in real life
it was initiated by pushbutton).

Some control centers used a second audio channel to distribute elapsed
mission time via IRIG. That wasn't exactly my kind of control center but I
got to visit them.

In decades past I worked extensively with analog multitrack telemetry and
voice recorders that would record the IRIG analog code at same time as data
and voice. On playback we would both watch pulses and carrier from IRIG on
pen charts and scopes to derive timestamps, and we would also hook up a
standard IRIG-driven clock to the recorded IRIG audio show where we were in
the playback. We had at least one special playback station that could show
IRIG time correctly through variable speed forward and reverse driven by
the IRIG audio carrier. Much later we used minicomputers with ADC's to
digitize the data, timestamp derived from IRIG audio.

Tim N3QE


On Sun, Jan 22, 2017 at 1:31 AM, Ruslan Nabioullin 
wrote:

> Hi, looking at pictures of various time metrology equipment setups for
> best practices and inspiration, I have commonly seen time of day display
> unit(s) installed in racks containing processing or time transfer
> equipment, e.g., http://www.xyht.com/wp-content/uploads/2015/05/Powers_
> Master_Clock.jpg. All that these units do is merely display the time of
> day and sometimes the date, typically by means of seven segment LED
> displays, of the time code inputted to them (typically IRIG-B, I'm
> guessing).  Any ideas why such a unit is necessary when one can simply look
> at the time displayed by timing receivers and time code generators (and
> even some standards), and the interface of some fusor, defined in this
> context as a system which performs timing data fusion (by implementing a
> paper clock or a more primitive algorithm) and timekeeping, either by means
> of a direct shell, or via something like NTP?
>
> Thanks in advance,
> Ruslan
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> ailman/listinfo/time-nuts
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>
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Re: [time-nuts] Li-ion Battreries

[Attila Kinali]

Hoi Bert,

On Sat, 21 Jan 2017 08:08:22 -0500
Bert Kehren via time-nuts  wrote:

> purchased  _2x  Samsung 35E 3500mAh 10A 18650 High Drain Rechargeable Battery 
>  
> INR18650-35E_ 
> (http://www.ebay.com/itm/112173495496?_trksid=p2060353.m2749.l2649=STRK:MEBIDX:IT)
>   for two reason 10 A load  and good price. These 
> cells have no protection, which I want, since I will for  our applications  
> stack 4 with a 4  cell controller and in two application also parallel cells 
> for a total of  8.  I have now completed my tests  and concentrate my 
> battery work on using these  cells. 
> After having tested 26650 cells with disappointing  results my focus is on 
> 18650. I am sure there will be 26650 cells available, but  right now our 
> focus is on 18650. 
> I have no connection in any way with these two sources,  but think it may 
> be helpful for those that look for batteris and do not want to  go through 
> the process I went through.   


Some small remarks: 18650 is by far the most common form factor
of Li-Ion batteries on the market. This is IMHO the better choice
than the 26650 if you want to be able to replace them in 10-20 years.

If you stack Li-* batteries, you will need to have a controller that
monitors each cell individually while charging or has some other means
of ensuring that none of the cells are overcharged (or rather that they
are charged the same amount). This kind of circuit is called balancer.
A protection circuit does _not_ replace a balancer. The protection circuit
is only to protect against catastrophic failure. Ie it is still possible
to overcharge a battery even if it has a protection circuit. You also do
not know what the protection circuit does to protect the cell. There are
a lot of chips out there, that simply open a switch and thus disconnect
the cell. In this case, the protection circuit of one cell will disconnect
the whole stack and break charging.

A lot of the multi-cell Li-Ion charger chips have integrated cell protection
circuitry. Ie if you use one of them, you will not need an additional
protection circuit. But be aware, the regulation for battery protection
circuit states that the circuit has to be wired fix onto the battery
in a way that this connection cannot be broken (without breaking the
housing of the battery pack). The reason for this is, i think, pretty
obvious. I would recommend that you solder each cell indidividually
into your circuit instead of using some kind of holder. Or if you are
using a holder, make it such that there is no chance any of the cells
can be accidentally short circuited.

Attila Kinali
-- 
Malek's Law:
Any simple idea will be worded in the most complicated way.
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Re: [time-nuts] purpose of time of day display units

[Poul-Henning Kamp]

In message <537e808d-731c-42de-90f3-bec55363b...@sfr.fr>, Mike Cook writes:

>All that these units do is merely display the time of day and
>sometimes the date, typically by means of seven segment LED displays,
>of the time code inputted to them (typically IRIG-B, I'm guessing).

I can imagine two reasons:

A) Trying to explain a $1M set of racks keeping track of time, without
   them actually showing the time is a lot harder.

B) Visual indication that your IRIG-B is fine.


-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] 10MHz to 25MHz

[David J Taylor]

From: Charles Steinmetz

Try this:


Best regards,

Charles
=

Not for the UK, it seems.  Is it on YouTube?  Could someone upload it 
somewhere?


Thanks,
David
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-tay...@blueyonder.co.uk
Twitter: @gm8arv 


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Re: [time-nuts] purpose of time of day display units

[Mike Cook]

Two reasons that come to mind are:
  Displaying distributed time to distant sites from some master.
  Readability at a distance.  


> Le 22 janv. 2017 à 07:31, Ruslan Nabioullin  a écrit :
> 
> Hi, looking at pictures of various time metrology equipment setups for best 
> practices and inspiration, I have commonly seen time of day display unit(s) 
> installed in racks containing processing or time transfer equipment, e.g., 
> http://www.xyht.com/wp-content/uploads/2015/05/Powers_Master_Clock.jpg. All 
> that these units do is merely display the time of day and sometimes the date, 
> typically by means of seven segment LED displays, of the time code inputted 
> to them (typically IRIG-B, I'm guessing).  Any ideas why such a unit is 
> necessary when one can simply look at the time displayed by timing receivers 
> and time code generators (and even some standards), and the interface of some 
> fusor, defined in this context as a system which performs timing data fusion 
> (by implementing a paper clock or a more primitive algorithm) and 
> timekeeping, either by means of a direct shell, or via something like NTP?
> 
> Thanks in advance,
> Ruslan
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"The power of accurate observation is commonly called cynicism by those who 
have not got it. »
George Bernard Shaw

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Re: [time-nuts] Thunderbolt Harmonics

[Rhys D]

Bill,

No offence taken at all. On the contrary, I really appreciate a great deal
the effort you have gone to straightening out my misconceptions and
blunders!

This forum is such a great learning opportunity. I usually work with
digital systems, so my RF and analog knowledge is sketchy at best. Half the
reason I bought a spectrum analyser is to have an excuse to learn a bit
about RF in a hands on way.

It's funny you mentioned the overly precise numbers. After I wrote them I
thought, well that's ridiculous, but I left them as is. That'll teach me!

Cheers,

Rhys


On Sat, 21 Jan 2017 at 2:37 PM, Bill Byrom  wrote:

> I'm trying to be gentle, Rhys. :)  I work with these issues every day at
>
> work. Here are a few more comments. I assume you have the preamplifier
>
> in the spectrum analyzer turned off.
>
>
>
>
>
> The term "X harmonic" (such as 2nd or 3rd harmonic) means a
>
> multiplication of the fundamental signal by the given factor. So the
>
> term "1st harmonic" isn't used -- that's the fundamental. The 2nd
>
> harmonic is 2X the fundamental, and the 3rd harmonic is 3X the
>
> fundamental. So in your examples you should have said "2nd and 3rd
>
> harmonics):
>
>
>
>
>
> 15 dB attenuation: 2nd harmonic is (-49.13 - +11.40)= -60.53 dBc
>
>
>
> 20 dB attenuation: 2nd harmonic is (-48.84 - +11.40)= -60.24 dBc
>
>
>
> 25 dB attenuation: 2nd harmonic is (-48.32 - +11.28)= -59.60 dBc
>
>
>
>
>
>
>
> In nearly all cases it's silly to compare RF powers to 0.01 dB
>
> resolution.  The uncertainty of the signal powers being measured,
>
> cable/connector loss, and instrumentation errors is in nearly all cases
>
> larger than 0.1 dB. Your spectrum analyzer doesn't have separate
>
> amplitude log linearly error specifications, but the total amplitude
>
> error with 20 dB of attenuation is specified as +/- 0.7 dB. So the 2nd
>
> harmonic values are not significantly changing as you change the
>
> attenuation, so the source you are measuring probably has about -60 dBc
>
> 2nd harmonic output.
>
>
>
>
>
> The 3rd harmonic results are going to cause me to wave my hands and make
>
> uncomfortable assumptions. The 20 dB 3rd harmonic level seems to be an
>
> outlier, but there is a possibility that a small amount of instrument
>
> distortion is out of phase with the source signal so that they partially
>
> null. RF measurements ARE magic in some cases. 
>
>
>
>
>
> The use of the external 20 dB attenuator means that the spectrum
>
> analyzer return loss is isolated from the signal source. What does that
>
> mean? Any RF signal traveling down a cable is slightly reflected by
>
> cable defects, connectors, filters, mixers, and imperfect attenuators or
>
> terminators. The reflected signal is called "return loss" and in some
>
> cases "VSWR" or just "SWR". If you had a perfect 50 ohm termination
>
> (load) at the end of a perfect 50 ohm cable, all of the power sent into
>
> the cable would be absorbed by the load and the return loss would be
>
> infinite. The phase of the reflected signal at the source output
>
> connector depends on the round-trip electrical length of the cable and
>
> the nature of the reflection. The reflection from a short is 180 degrees
>
> different from an open, and other types of load can produce different
>
> reflected phases. By the time the reflection gets back to the source
>
> connector, the phase of the reflected signal can cause the impedance to
>
> appear to be nearly anything (greater or less than 50 ohms and probably
>
> capacitive or inductive). If you change the source frequency there is a
>
> different phase round-trip delay due to the wavelength changing, so in
>
> general the RMS voltage at the source will have some ripple vs
>
> frequency. If you place that 20 dB attenuator directly on the source
>
> output connector, the return loss that the source "sees" is nearly
>
> completely controlled by the quality of the attenuator. Even if the
>
> cable had an open or short at the end, the signal passes both ways
>
> though the attenuator so the return loss must be >40 dB (assuming a very
>
> high quality attenuator). This is the same as saying that the VSWR
>
> (Voltage Standing Wave Ratio) is close to 1. A 40 dB return loss
>
> corresponds to a VSWR of 1.02. If an RF filter doesn't see a low VSWR
>
> load, it may not produce the desired filtering behavior.
>
> --
>
>
>
> Bill Byrom N5BB
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> On Thu, Jan 19, 2017, at 10:48 PM, Rhys D wrote:
>
>
>
> > Thanks for the detailed post Bill,
>
>
>
> >
>
>
>
> > I'm learning a lot here!
>
>
>
> > So the spectrum analyser is indeed a "trap for young players"
>
>
>
> > As you guessed, it is a Siglent SSA3000X series analyzer.
>
>
>
> >
>
>
>
> > I just looked at the same signal again with varied attenuations
>
> > dialed in
>
> > on the instrument (I am using an external 20dB attenuator from
>
>
>
> > minicircuits
>
>
>
> > as well)
>
>
>
> >
>
>
>
> > Here is what I saw:
>
>
>
> >
>
>
>
> > 

[time-nuts] purpose of time of day display units

[Ruslan Nabioullin]

Hi, looking at pictures of various time metrology equipment setups for 
best practices and inspiration, I have commonly seen time of day display 
unit(s) installed in racks containing processing or time transfer 
equipment, e.g., 
http://www.xyht.com/wp-content/uploads/2015/05/Powers_Master_Clock.jpg. 
All that these units do is merely display the time of day and sometimes 
the date, typically by means of seven segment LED displays, of the time 
code inputted to them (typically IRIG-B, I'm guessing).  Any ideas why 
such a unit is necessary when one can simply look at the time displayed 
by timing receivers and time code generators (and even some standards), 
and the interface of some fusor, defined in this context as a system 
which performs timing data fusion (by implementing a paper clock or a 
more primitive algorithm) and timekeeping, either by means of a direct 
shell, or via something like NTP?


Thanks in advance,
Ruslan
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