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Controlling a Induction Heating Power Unit
Controlling a 0-10 V module for Power Unit Control

Hi everybody, and thanks for your time.

I'll briefly explain my issue. I have to build a control system for a power supply unit. The power supply has a 0-10 V standard dc input as a drive signal, so 0 V corresponds to no power and 10 V corresponds to 100% of power. I would need an analog module which have a 0-10 V input and output, with a resolution and precision as low as possible, i.e. something of the order of mV. That device can moreover be connectable to PC, possibly through serial bus and Modbus protocol. do you know a brand or a specific device which corresponds to my need?

Thank you so much, and sorry for my english.

1. Resolution

To get millivolt resolution on a 10.0V span, you need 10,000 counts, assuming the span is 10.0.

A 14 bit unipolar A/D will provide 1 mV resolution with 16,384 counts.

A 14 bit A/D with a sign bit will not quite make 10,000 parts, with 8,192 parts, but might be close enough for government work.

Of course, accuracy is a horse of a different color. 0.1% accuracy is accuracy to 0.010V on a 10V span. Repeatability might or might not be better.

2. This M-7024 has 14 bit resolution, current or voltage output, Modbus RTU.

https://www.icpdas-usa.com/documents/cut-sheet-M-7024.pdf

3. Without any input, there's no prospect for feedback control. This is going to be manual control? You type in a number and the voltage input to the power supply changes? Why a requirement for such fine resolution for manual control?

I'm sorry. I forgot to include those information. We have also an input signal consisting in a 0-10 V analog voltage signal too. Input and output modules must moreover be electrically isolated.