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I want to Measure 150Vdc…

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MISAKAREE:
I want to measure the voltage from a 150 Vdc generator to Arduino.
The voltage will change from 0 - 150 Vdc.
What equipment should I use to separate the ground system?  :'(

TimNJ:
Can you clarify the following?

1.) Do you want to measure between 0 and 150V using an an Arduino's ADC?

2.) Can you re-explain what you mean by: "What equipment should I use to separate the ground system?"

Brumby:
Yes - a bit more detail would help here ... especially about why you ask this:
--- Quote from: MISAKAREE on January 17, 2019, 01:37:50 pm ---What equipment should I use to separate the ground system?

--- End quote ---

Do you have incompatible ground reference points?  And if you do, we would need to know more about the situation to be able to comment intelligently.

spec:

--- Quote from: MISAKAREE on January 17, 2019, 01:37:50 pm ---I want to measure the voltage from a 150 Vdc generator to Arduino.
The voltage will change from 0 - 150 Vdc.
What equipment should I use to separate the ground system?  :'(

--- End quote ---
Hi MISAKAREE

This is a common requirement where you have two systems with different 0V references (grounds) and you want to keep them separate.

You can do it with some fancy electronics, using an isolated communications interface, but the simplest way is with a swinging capacitor.

I will knock up a schematic to show how it works.

Zero999:
If the circuits both share the same reference, then a potential divider is all that's required.

R1 = 180k or 1M8
R2 = 62k or 620k
Will give an output of 4.995V, with an input of 150V, an error of -0.1%.

Put a 10nF capacitor across R2 to provide a low impedance AC path for the MCU's sample and hold capacitor's charge to flow in/out of.

The component values were selected using the calculator linked below:
https://www.random-science-tools.com/electronics/divider.htm