SparkFun Forums

[khetanikrunal]

HELLO,

Can anyone suggest me right controller for measuring high voltage?

Here are the specs..

1) i/p is 0 - 5Vac(1kV to 50kV)
2) 16/>16 bit ADC
3) Two voltage channel and one current channel.
4) Single chip (MCU+ADC) or MCU with external ADC.

Waiting for reply.

Thanks,
Krunal khetani

[MichaelN]

What other features does this project require? Will it have LCD screen, keypad, USB etc? What MCU do you have development tools for and experience with? Your choice of MCU would probably be decided by these things.

As for ADC, I'm not aware of many (any?) MCUs that have inbuilt 16-bit ADCs, so this would dictate a separate ADC.

Is the HV you want to measure referenced to ground? If so, this would make current and voltage measurements easier.

In any case, you will require some special construction techniques to safely measure 50KV! As well as string of special high-voltage resistors, you'll need to provide suitable geometry of your PCB and encapsulation etc.

[marcovansteen]

well almost any controller will do as long as the speeds are not too high.
the problem is probably more on the high voltage sensor side and the adc, e.g. safety, creepage and clearances, isolation barrier etc.
On chip (dual slope) adc's only work at 16 bit for very slow speeds and gives limited performance in terms of speed, drift and noise. you need to know a lot of details before you can decide if an on-board adc will do the job.
if cost and space are not too much of a concern, it's easier to use an external adc. Read a lot of data sheets or ask a mixed signal designer to design something for you, as it is not trivial to squeeze all the promised performance out of an adc (i know by experience ).