[neonixie-l] Re: GR10M/U Nixies Available

[Jasper C.]

Hi Roddy, I dropped you a PM a few days ago.  Did you receive it?  First 
time using the PM feature for me, wasn't sure if I made a mistake.

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/3debe89c-7b07-4e57-a532-b98de38341fc%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[neonixie-l] Re: GR10M/U Nixies Available

[Jasper C.]

No worries about the delay.  I was just wondering if something might have 
happened.



On Wednesday, 13 March 2019 05:36:17 UTC+8, Roddy Scott wrote:
>
> I emailed you tonight, Jasper. 
> I have been trying to get the total amount requested sorted out. 
> Sorry for the delay.
>
> On Tuesday, March 12, 2019 at 12:15:42 PM UTC, Jasper C. wrote:
>>
>> Hi Roddy, I dropped you a PM a few days ago.  Did you receive it?  First 
>> time using the PM feature for me, wasn't sure if I made a mistake.
>>
>

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/ee2141ec-3994-4824-ba6b-44d7e057fe64%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Re: [neonixie-l] Lot's of high priced B7971 from France...

[Jasper C.]

Ouch.  I guess there's no chance for those of us who are late to the hobby 
to ever pick some of these up at "affordable" prices?  (Affordable to me.  
I'm sure there's always going to be someone out there who's comfortable 
with it.)



On Tuesday, 16 April 2019 06:56:31 UTC+8, Bill Notfaded wrote:
>
> At least when I usually paid that high of price for tubes they didn't ask 
> for additional shipping is was included in the price that's all.

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/5db99ea9-ee7a-458f-8044-6d4d63253008%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[neonixie-l] Tube/bulbs for colon separators?

[Jasper C.]

What are my options for colon separators to use in a nixie clock?  I'm 
looking for something that works with small tubes, say GR10M/U or even 
better, IN-17s.

I know there's the INS-1, but it does still seem a little big.  I also know 
Yan has some 3mm neon bulbs on his store, but are those a good match to 
nixies?

While I'm at it, are there any equivalent tubes (colon separators) for VFDs?

Thanks!

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/e4e84487-15b4-478b-aaf4-8ef616ca5c49%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Re: [neonixie-l] Tube/bulbs for colon separators?

[Jasper C.]

Thanks.  I'll give the 3mm neon bulbs a try, those are as small as I've 
found.  Only thing is they need 60V AC.  Not impossible, but an annoyance 
to have to put in another power rail.  I already have some INS-1s on order 
too.

Will also have a look at the 6977s.  Hadn't come across that one before.

I'll also have a look at the IV-15.  Never thought of using that as as an 
indicator, and always thought it was bigger than it actually is.

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/b974d5dc-5ea8-4b84-8dd4-3a0e304aec78%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[neonixie-l] Re: Tube/bulbs for colon separators?

[Jasper C.]

Hi Yan,

Thanks!  Those pictures are useful.  Will be giving the 3mm neons a try.

Have just placed an order from your store for 2 of the NCH8200HV power 
supplies, and sent you a PM about the 3mm bulbs.



On Sunday, 28 April 2019 20:04:51 UTC+8, 严泽远 wrote:
>
> Hi Jasper,
>
> I'm using φ3x12mm neon lamps for my Omnixie clock, two neons covered by a 
> φ6mm glass tube, glass tube fixed on PCB board by an O ring.
> You also can drive them easily with DC170V, just connect a 240K resistor, 
> same color with Nixie tubes even dimming by PWM controller.
> Please check pictures.
>
> Yan.
>
>
> 在 2019年4月27日星期六 UTC+8下午11:07:11，Jasper C.写道：
>>
>> What are my options for colon separators to use in a nixie clock?  I'm 
>> looking for something that works with small tubes, say GR10M/U or even 
>> better, IN-17s.
>>
>> I know there's the INS-1, but it does still seem a little big.  I also 
>> know Yan has some 3mm neon bulbs on his store, but are those a good match 
>> to nixies?
>>
>> While I'm at it, are there any equivalent tubes (colon separators) for 
>> VFDs?
>>
>> Thanks!
>>
>

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/45e5f1d1-166f-4c48-91a0-c4c760bb66b1%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[neonixie-l] VFD filament resistance when hot/cold?

[Jasper C.]

I'm working on a project using some IV-17 tubes, and I cam across something 
I need advice on.  The datasheets I've found say that the filament current 
is 47 mA at 2.4 Vac, so an effective resistance of about 51 Ohms.  But on 3 
tubes I've measured, they're all about 20 Ohms.  Does the filament 
resistance change when hot?  Because that seems like a huge difference...

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/1aa2a39c-df1e-462b-b271-79d8bebf796co%40googlegroups.com.

[neonixie-l] Re: VFD filament resistance when hot/cold?

[Jasper C.]

On Friday, 17 July 2020 01:56:47 UTC+8, Paul Andrews wrote:
>
> What power supply are you using? I seem to collect power supply design 
> almost as much as Nixie tubes.
>
>

I'm planning to use an LM9022 based supply.  Yes, it's out of production, 
but apparently it's the same as an LM4871.

And yes, it's overkill for a single IV-17, but I plan to start here, then 
get one of those multi-digit tubes to play with.  Having one PSU design 
will cut down on the work.

Thanks for all the replies.  I'd never thought about managing inrush 
current and burnout.  I'm not sure it's possible to do with the LM9022, or 
at least not with my level of analog know how.  But it occurs to me that 
the Vsupply for that chip is 2.0 to 5.5 V.  I could use a 
resistor-divider-set LDO to supply the LM9022, and use a digital pot + 
small uC to do a "soft-start" by starting at a low voltage then ramping 
up.  As a bonus, since I plan to have a uC in the clock anyway, I can tie 
the digital pot to that in my final design...

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/5bab3541-effd-44bc-a61a-2e7fd64eb5aco%40googlegroups.com.

[neonixie-l] Just starting out, where's a good point to start from?

[Jasper C.]

Hi all!  After lurking here for a while I've decided I really should start 
taking my first steps into building something with nixies.

But what would be a good tube series to start with?  I remember reading 
somewhere that IN-1s tended to be not so reliable, but I'm not certain 
about that.  I was thinking of starting with IN-12s as they seem common, 
and maybe IN-17s for their small size.

Also is there a recommended starting point for looking at power supplies?  
I have an engineering background, but not much experience with switching 
power supplies.  In particular I'm wondering if there are any actual 
current regulated supply designs out there - the ones that I've come across 
all seem to make use of a constant voltage and a resistor.

Cheers!

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/fb2dba53-1433-4485-a7b7-4a436d276096%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[neonixie-l] Push-pull driving cathodes

[Jasper C.]

I'm still new when it comes to nixie tubes, and was reading this page 
, in particular the 
"partial glow" that occurs if the prebias voltage of an "off" cathode is 
too low.  Wouldn't that imply that the ideal solution would be to pull the 
cathodes to the supply voltage of the anode when their respective segment 
is off?

Only in this EEVblog video, starting at 14:25 
, he does just that and it doesn't go 
well.  I get that the anode voltage here is lower than the HV supply 
because of the 22k resistor, though I don't understand why that then has 
the effect that it does.  Is the segment shorted to HV acting as an anode? 
(Which might explain the higher current he's seeing.)

Would a totem pole circuit like that work if the anode resistor was removed 
and each cathode connected to the totem pole output by it's own resistor?

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/144bce53-142d-44be-9a9b-fae08fafab7b%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Re: [neonixie-l] Push-pull driving cathodes

[Jasper C.]

On Sunday, 3 March 2019 20:53:04 UTC+8, David Pye wrote:
 

> Yes, that's it.  If the other segments are high, they just work as more 
> anodes.
>
> The best thing imho is just to leave them floating, but they will then 
> float up to the anode voltage. So provided you have drive circuitry that 
> can switch the full anode voltage, that is ok.
>

I'm a little confused there, about it being OK to switch the full anode 
voltage.  Do you mean that the low side switch can handle the full HV, or 
that I switch my cathodes to HV?  The latter would contradict the "working 
as more anodes" issue.


-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/76834d66-5acc-40b5-920a-2023067f14bf%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Re: [neonixie-l] Push-pull driving cathodes

[Jasper C.]

So I was originally looking at the Microchip HV513 
.  It's a 250V totem pole 
driver with 5V input logic and a latch.  Was going to do a quick sketch of 
what I had in mind for the output, but haven't had the time to get round to 
it.

I was planning to not multiplex my nixies, probably leaving all cathodes 
connected directly to the HV line, and placing current liming resistors on 
the cathodes.  Was interested to see if I'd need to tweak any of the 
individual resistor values uniform current/brightness.

If I implemented only a low side switch, I was looking at something like 
the MMBTA42, available from a few manufacturers and is good for 300V, but I 
haven't yet found any information about leakage currents when the device is 
off.  Alternatively I think I found a mosfet or two with sufficient V(DS) 
and logic level switching, but I need to recheck the D-S leakage.

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/80ca1625-c43a-47fc-a115-eeff6130f4e2%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Re: [neonixie-l] Push-pull driving cathodes

[Jasper C.]

On Monday, 4 March 2019 04:12:55 UTC+8, nixiebunny wrote:
>
> The voltage applied to the elements of a Nixie tube is not as 
> straightforward as you may think. Keep in mind that there is a voltage drop 
> from anode to an 'on' cathode of ~130-140 volts, due to the ionized gas. 
> Also, the capacitance of the tube elements and wiring has an effect on the 
> switching behavior.
>
> I have successfully made several varieties of multiplexed Nixie clocks and 
> watches using 60V or lower cathode switches. I used printed circuit boards 
> to reduce capacitance, and adjusted the timing to allow the recently turned 
> off cathodes to drift up to their natural 'off' voltage before turning on 
> the next digit's anode.
>
> My Nixie watch design uses 50V cathode switch arrays. It also has no anode 
> resistor. This is done by enabling only one cathode at a time, leaving the 
> other tube with no cathodes enabled. 
>
> The power supply has a resistor current sense and feedback mechanism to 
> regulate the total current as well as the open-circuit voltage. Blanking is 
> achieved by reducing the anode voltage to 100V, with a digitally controlled 
> shift to the regulator feedback. 
>
> So you can get good results with very little circuitry, if you apply a bit 
> of cleverness to the problem.
>
> http://www.cathodecorner.com/nixiewatch/firmware/nwrf-schem.gif
>
> The feedback regulated power supply is a very elegant solution, and I'd 
love to implement something like that, but my knowledge of switching power 
supplies isn't good enough to pull it off.  I envy you.

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/892ef4d6-d71e-45a8-ab96-30aa6beb5cc8%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Re: [neonixie-l] Push-pull driving cathodes

[Jasper C.]

>
> I was planning to not multiplex my nixies, probably leaving all cathodes 
> connected directly to the HV line, and placing current liming resistors on 
> the cathodes.  Was interested to see if I'd need to tweak any of the 
> individual resistor values uniform current/brightness.
>

I only just reread what I wrote there, and realise I made a typo.  I should 
have said I was going to connect all the anodes to the HV line...


On Thursday, 7 March 2019 00:41:00 UTC+8, nixiebunny wrote:
>
> Another important fact about Nixie tube cathodes: turning on one cathode 
> by pulling it to zero volts causes it to steer all the available current 
> away from the other cathodes, causing them to be dark. This is why you only 
> need a 50V switch on each cathode. 
> The caveat is that if no cathodes are pulled to zero volts, then there 
> will be leakage current flowing through the tube that will destroy a 50V 
> transistor. This is why I used the TD62083 with its set of commutation 
> diodes, and connected the diode common anode pin to a 50V source in my 
> Nixie watch circuit.
> It's also why I made the blanking mode that drops the anode voltage to 
> 100V, so that the cathodes all remain dark when blanked. 
>
>
Ah, well that comes back to the page I referenced in the opening: 
http://www.decodesystems.com/re-how-nixies-work.html.  Maybe that was 
written in reference to having leaky cathode transistors? (With no voltage 
clamp, as in Fig. 4.)  If I had say 300V+ transistors with sufficiently low 
leakage when off (< 10 uA) and a 170V power supply, would I be able to 
blank the tube safely by turning all transistors off?

I'll have another look at power supplies. :)  I was a little concerned 
about how to calculate the value of the loop compensation components.  For 
my first attempt I figured I'd avoid the problem altogether by using one of 
Yan's power supplies, and focus on the segment driving circuitry.
 

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/7026df09-ef22-408c-9e92-7daa3f5f2db6%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.