Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

How to measure voltage of above 10kV using an MCU

Status
Not open for further replies.

samuelr

Member level 4
Joined
Sep 23, 2008
Messages
78
Helped
4
Reputation
8
Reaction score
2
Trophy points
1,288
Activity points
1,861
I am trying to find a way to safely sample a high voltage output which will travel from about 1kV to 20kV (ramp).

I think using a resistor divider should do the job. I have been successful at 1 kV - 2 kV range. I am just wondering if just by using a high impedance resistor will do the trick.
Any advise?
 

Vbase

Full Member level 6
Joined
Apr 7, 2015
Messages
367
Helped
74
Reputation
148
Reaction score
72
Trophy points
28
Activity points
1,997
Use carbon composite resistors in series. If you find the datasheet you will be able to tell what is the max working voltage, if it's say 500V series at least 20 of them and put them inside plastic rube.
Don't use metal film resistors or carbon film resistors, they often arc between the windings and go open circuit. They also have higher inductance that increases the error with the input capacitance of the ADC.
 

betwixt

Super Moderator
Staff member
Joined
Jul 4, 2009
Messages
14,366
Helped
4,727
Reputation
9,469
Reaction score
4,495
Trophy points
1,393
Location
Aberdyfi, West Wales, UK
Activity points
122,588
I agree with Vbase over the chain of resistors but I would also include a high input impedance buffer amplifier between the voltage tap and the MCU. The reason is that most MCU, assuming you are feeding directly into an ADC, need to see a low impedance. The chain of inevitably high value resistors is likely to cause serious reading errors because of the long time constant they create with the ADC input circuits. A buffer will increase the current available to the ADC while not unduly loading the voltage from your divider chain.

Brian.
 

Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top