Author Topic: Low current high voltage current measurement  (Read 1520 times)

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Offline tmf

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Low current high voltage current measurement
« on: June 01, 2015, 04:23:38 pm »
I have search and search for this information online and can not find.

I have made a zapper type ciruit, 2KV output probably a few millamps. I want to measure the "zap" current. How to isolate and what will be needed for a uC to get this information?

Also want to do it on the cheap.

Richard.
 

Offline rolycat

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Re: Low current high voltage current measurement
« Reply #1 on: June 02, 2015, 02:23:26 am »
There are lots of "zapper type circuits" - it would be useful if you provided a little more information:

Do you have a circuit diagram you can share?
Why do you want to measure the current with a computer?
How cheap is cheap, and what equipment do you have?
What are you zapping - mosquitos, sparks, people?
 

Offline tmf

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Re: Low current high voltage current measurement
« Reply #2 on: June 02, 2015, 04:02:46 am »
Mainly bugs, would just like to know the intensity, maybe just detect the length of zap and not current, it may be the same current all the time.... not sure what to expect. See image attached.

 

Offline rolycat

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Re: Low current high voltage current measurement
« Reply #3 on: June 02, 2015, 10:27:06 am »
A current transformer hooked to a fast ADC would be a good starting point and would give you a voltage proportional to the current together with isolation. You should also be able to measure the discharge duration. Because you have a high voltage and low current you might have to wind your own.
 

Offline tmf

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Re: Low current high voltage current measurement
« Reply #4 on: June 02, 2015, 12:54:49 pm »
A current transformer hooked to a fast ADC would be a good starting point and would give you a voltage proportional to the current together with isolation. You should also be able to measure the discharge duration. Because you have a high voltage and low current you might have to wind your own.

Would the extra resistance from the windings kill the zap or at least attenuate it? Need to look up current transformers and see how they work.

Thanks!
Richard.
 

Offline HighVoltage

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Re: Low current high voltage current measurement
« Reply #5 on: June 02, 2015, 01:45:23 pm »
Cheap way: Series Resistor against ground and measure the voltage drop
Real way: Current transformer with BNC connector directly to the scope

There are 3 kinds of people in this world, those who can count and those who can not.
 

Offline G7PSK

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Re: Low current high voltage current measurement
« Reply #6 on: June 02, 2015, 02:54:13 pm »
As the thing makes a spark just looping the earth lead to the probe point may well pick up any RF and from that you can work out the spark duration.
 


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