Author Topic: 0-10v calibrator, basics, idea, questions, target  (Read 228 times)

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Offline sraken13

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0-10v calibrator, basics, idea, questions, target
« on: October 21, 2019, 07:01:04 pm »
Hello, I have nothing to with electronics but I have good electrical background. In my past Ive been programming atmega8 ~~

I want to ask simple questions and I will appreciate any answer that can lead me in close future to creating my own regulated dc power source, 0-10V, mV steps, some % accuracy for calibrating purpose.

on what components to base?

I know about adjustable voltage regulators like LM317 for example, or precision voltage reference chips with ability to trim the output but not in such a range of 0 to 10
I wish to know a bit more of basics and design of accurate voltage calibrator, lets assume; no display, no measure, output accuracy 1%, 0,5%, 0.2% or even less; 0,05 or 0,02 or 0,01. I have budget but absolutely no clue. Throw some ideas, datasheets, circuits or complex solutions for my better understanding, eventually I will grow up. Thank You.

 

Offline MosherIV

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Re: 0-10v calibrator, basics, idea, questions, target
« Reply #1 on: October 21, 2019, 07:38:42 pm »
Hi

Welcome to the forum.

So you are after something like this:
https://www.rohde-schwarz.com/us/product/r6240a-productstartpage_63493-9189.html

They are not power supplies, they are a 'voltage source'

You would be better posting in the metrology section.

Have a look at what this guy has produced
https://www.eevblog.com/forum/metrology/new-pdvs2mini-dc-voltage-reference-from-ian-johnston-reviewed/

Basically, you need a high stability precision voltage reference.
This then is the voltage reference for a high resolution DAC.
The DAC then needs to drive a voltage buffer/amplifier (try a transistor in emitter follower mode).
Once all this is working, you characterise the output for linearity and program the set point voltages into a look up table whuch is used to program setpoint voltage for the DAC.

 

Offline sraken13

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Re: 0-10v calibrator, basics, idea, questions, target
« Reply #2 on: October 21, 2019, 08:37:10 pm »
ah so i need DAC  8) gonna study about them.

I found forum index: Best out-of-the-box 10V reference, seems to be useful for me.
https://www.eevblog.com/forum/metrology/best-out-of-the-box-10v-reference/

that r&s 10 ┬ÁV / 1 nA resolution ;DDD a bit too much for me and my needs.

main purpose of mine is sourcing mV to simulate thermocouples and sourcing V to analog inputs of plc. I already own professional equipment to do that,
but want to learn more in depth even if that thing will never get out of the breadboard.  :)

 

Online Andreas

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Re: 0-10v calibrator, basics, idea, questions, target
« Reply #3 on: October 21, 2019, 09:13:41 pm »
a good entry would be Conrads article:
http://conradhoffman.com/mini_metro_lab.html

Build or buy that is the question.
Ian sells 0-10V calibrators at a very attractive price.
Considering that you will probably need years until your first working sample is built.
https://www.eevblog.com/forum/metrology/new-pdvs2mini-dc-voltage-reference-from-ian-johnston-reviewed/msg2647110/#msg2647110

with best regards

Andreas
 

Online imo

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Re: 0-10v calibrator, basics, idea, questions, target
« Reply #4 on: October 22, 2019, 06:20:12 pm »
If you want to learn something you may try the PWM source below (an example).

The PWM 5V signal is generated by arduino (your atmega8 for example).
At the output you will get around 1.3-10.00V with PWM duty 0-100%.
In the simulation below the 1kHz 5V signal with 50% duty creates aprox 5.000V at the output.
The real voltage will be +/- few mVolts off because of many factors.

Mind the precision and stability and is not great. You may play with it and improve it with more skills.

PS: add 100uF/25V capacitors at the input and output of the LM317.
« Last Edit: October 22, 2019, 06:51:53 pm by imo »
 


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