e offsetting effect - but this might be a significant contributor to the 5
ppm error that is mentioned.
There is also a 6 nA (typical) leakage mentioned. During the "hold" time (
about 1 msec) of the output 1 ufd cap this comes to 6 uV.
Regards,
Bob Smither
<>__
Does anyone know the basic specs for a Data Precision 3600 - resolution,
accuracy?
Thanks!
--
Bob Smither, PhD Circuit Concepts, Inc.
=
If you don't read the newspaper yo
d a 3458A!
--
Bob Smither, PhD Circuit Concepts, Inc.
=
Government is not healthy for children and other living things.
-- Je
On 08/09/2013 10:40 PM, Joseph Gray wrote:
> I'll probably send the HP 3478A off for calibration after I get paid next
> week. Being 6.5 digit and freshly calibrated, it will be interesting to see
> how it reads the 510A.
The 3478A is a 5.5 digit instrument (resolution of one part in 300,000).
(another 3457A owner (actually three))
--
Bob Smither, PhD Circuit Concepts, Inc.
=
Blessed is he who expects no gratitude, for he shall not be disappointed.
-- W. C
B as well. Try EBay.com. Search for
"j505 current" and you will find them.
--
=============
Bob Smither, PhD Circuit Concepts, Inc.
"There is no worse tyranny than to force a man to pay fo
nt to
the 731A output and leave the 1K inside the loop. I would prefer to not butcher
the board. Clearly shorting the 1K is pretty easy! The lm301 is protected
against shorts to ground.
Thanks to all who added to this thread.
--
===
protection to the
op-amp and may be a factor in the op-amp stability.
Other than the above, can anyone see why this would be a bad idea?
Thanks,
--
Bob Smither smit...@c-c-i.com
Circuit Concepts, Inc. 281-331-2744
body knows the answer?
I believe it it to prevent negative lockup of the circuit output upon start.
--
Bob Smither, PhD Circuit Concepts, Inc.
=
"If you want peace, work f
long term operation? What would be expected over the second 1000 hours, etc?
Would we expect a drift of 1.4 * X ppm over 2000 hours, sqrt(10) * X ppm over
10,000 hours, and so on?
Thanks,
--
=======
Bo
On 10/18/2012 02:05 PM, Andreas Jahn wrote:
> Hello Bob,
>
> whats the matter with you. Infected by precision virus like me?
> You wanted to have a standard with about 10ppm and now you blame a 3-4ppm
> drift.
:-) - afraid so Andreas!
>>
>> The LM199A is hermetically sealed.
>>
>
> The PCB, th
whatever caused the drift - similar range of drift, similar time constant.
Details (schematic, etc.) about the TS are available at the above link.
Any ideas about what could cause the drift we are seeing?
Thanks!
--
Bob Smither smit...@c-c-i.com
On 09/22/2012 02:24 PM, Bob Smither wrote:
> I just dropped off the Volt-Nuts TS at my shipper, headed to the fourth
> volunteer for this project. I will report his measurements as they become
> available.
Some drift data provided by the fourth volunteer is now available here:
h
I just dropped off the Volt-Nuts TS at my shipper, headed to the fourth
volunteer for this project. I will report his measurements as they become
available.
The prior readings are here:
http://c-c-i.com/ts
--
Bob Smither, PhD Circuit Concepts, Inc
fellow volt-nut across the Atlantic has expressed interest, but we have not
found an economical way to ship it.
Best regards,
Bob Smither
<>___
volt-nuts mailing list -- volt-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/li
inal calculation appears to be wrong.
Using 45 uOhmCm:
45E-6 * 434 in * (2.54 Cm / in) / (pi * (.005 cm / 2)^2) = 2.52 KOhm
At the risk of stating the obvious, have you considered Vishay resistors for the
rebuild?
Best regards,
--
Bob Smither, Ph.D.
charted the difference between the new one and one
that has thousands of hours on it. Interesting to watch it settle in over a few
days.
Best regards,
--
Bob Smither, PhDCircuit Concepts, Inc.
==
ip to some of us volt nuts. When I get it back I leave it on 24/7
to get it along towards its ultimate stability.
--
Bob Smither smit...@c-c-i.com
==
The powers not delegated to the
hen power is first applied heater current
spikes to typically above 120 mA. After a few seconds it drops to a 10 - 40 mA
(depends on heater voltage level and environment).
--
Bob Smither, PhD Circuit Conc
On 08/26/2012 05:06 PM, J. L. Trantham wrote:
> Anyone heard from Bob Smither lately? I emailed him direct but have had no
> response.
Hi Joe,
Been somewhat out of touch with my e-mail dealing with a health issue. I will
respond to your message from 08/21.
Thanks!
--
Bob S
On 07/11/2012 09:01 PM, Mike S wrote:
> On 7/11/2012 5:15 AM, Frank Stellmach wrote:
>> This is the worst realized electrical unit, i.e. the 'mise en pratique'
>> is difficult to an error level of about 1e-7 only.
>
> On 7/11/2012 6:50 PM, Bob Smither wrote:
>>
esistor excess noise - a 1/f noise source that can
be much larger than the thermal noise - but I would think that engineers at HP
would pick a resistor technology (bulk metal foil) that minimizes that noise
source.
Best regards,
--
Bob Smither, P
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