super expensive DIY voltage refference.

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super expensive DIY voltage refference.

Post by EATyourGUITAR » Fri Nov 29, 2019 10:59 am

if anyone needs a voltage reference that can do 7.xxxxxxV accuracy here is all the schematics and info you need

to test your reference, you will need a $3000 volt meter with 7-1/2 digit resolution. or you can visit a calibration laboratory. maybe your local university can help you. what you get from this is anything between 7.1V up to 7.5v. it is completely random what you will get but it will stay the same for life of your individual sample provided you follow the 1 year burn in procedure.


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Post by devinw1 » Fri Nov 29, 2019 1:21 pm

Sounds like a plan! :lol:

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Post by guest » Fri Nov 29, 2019 2:14 pm

whooa, wait a second here. the LTZ1000 is a heated matched pair, as best i can tell. has anyone used one as an expo converter? granted, its 60$, but maybe someone finds it worth it? thanks for posting that.

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Post by Orgia Mode » Fri Nov 29, 2019 2:47 pm

wooooow digits for days.

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Post by megaohm » Fri Nov 29, 2019 4:27 pm

The BOM for that lists raw parts cost as $300+.
It's a special thing so not terrible.

There is also a low cost, less precise version using two LM339.
They have an OSH Park pcb file to use for that one, too.

Thanks for posting this. Enjoying the read.

Will work for pistachios

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Post by emmaker » Fri Nov 29, 2019 9:26 pm

That's not to bad. One of the calibration generators I had to use on one of my jobs cost $250K with 5 test heads.

Another job to test and qualify the product there was a 2 rack system (by rack here I mean 6' instrumentation rack) that I was told cost $1.5M. It was filled with gear from Tektronix, Keithley and Agilent/Keysight.

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Post by elektrouwe » Sat Nov 30, 2019 8:18 am

guest wrote:whooa, wait a second here. the LTZ1000 is a heated matched pair, as best i can tell...
well, 60..70$ for an expo is a lot of money compared to a 60..70cent LM13700, who can do this too. But whooa, wait a second here ;-) can't we use a LM13700 as heated precision zener ? Darlingtons as heaters & Iabc mirror (see expoOTA) as temp sensor and reverse breakdown lin. diodes as zeners ? probably find some time next week to check this...

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Post by neil.johnson » Sun Dec 01, 2019 1:53 pm

What a complete waste of time. Buy a calibrated 10v source for $75.00 ($89.50 if you want it in a box) and get on with building synths!

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Post by revtor » Sun Dec 01, 2019 7:44 pm

Love the pcb layout on they thing... the art of the science of the layout..

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