simulate a current using an electronic circuit

[cgetty]

Hi

I would like to simulate a current. Also to do it using an electronic circuit.

I work as a test tech for an electric utility. There are times that I want to simulate current flowing in a device. Like driving a kwh meter with out having it installed in an actual ciucuit.

I know how to do this using a varyack (adjustable transformer) by feeding voltage into the secondary of a CT. But I want to try it using an electronic circuit.

Someone in this post thread956-111849 said “audio power amplifier might be the most cost effective solution”. I'm looking to build something (or buy if its low cost) that I can use here in the shop.

Also want to learn how it works ( doing it using an electronic circuit ). Looking for plans or a kit or links on the web.

Thanks
Clark

 

[jtkirb]

What kind of current are we talking about? I assume 0 to 5 amps, but you also need to know the burden.

accuracy is also an issue. What are you using it for?

You could borrow the relay test sets that your utility is sure to have and not have to make one.

JTK

 

[cgetty]

>What kind of current are we talking about? I assume 0 to 5 amps, but you also need to know the >burden.

Yes to start with 0-5 is what I'm looking at.

>accuracy is also an issue. What are you using it for?

To drive kwh meters & over current relays.

>You could borrow the relay test sets that your utility is sure to have and not have to make one.

We don't have one. Were a small utility, we contract relay test out (trying to change that). I can't even to fork out 6000.00 for this one. PTE-100-C

http://www.noramsmc.com/

Clark

 

[waross]

You may have a problem with phase relationships using an audio amplifier. You may be able to use a small 60Hz signal from the mains and amplify it with your audio amplifier to drive the current coils. That would give you the same frequency for both your current coils and potential coils. Then if you have a dual trace scope you can check your wave forms and phase angles. If you take your potential voltage from "A" phase and
use a Variac or potentiometer from "B" phase to "C" phase you will be able to invert the signal and dial up a phase shift adjustment from plus 60 deg to minus 60 deg. to feed into the audio amp. Take the signal from the wiper of the Variac or potentiometer to the neutral. Use small transformers as required.
yours

 

[Skogsgurra]

Do not double-post. It creates confusion.

Gunnar Englund

http://www.gke.org