Regulate and verify an AC current to test a current transducer sensor

current measurement

Firstly my background in software so this is a bit of foreign territory for me.

I have the requirement to monitor an AC current between 0 and 3 Amps. The plan so far in to use a non invasive current transducer sensor connected to an analogue input on a device connected to a PC. Something like this appears to be what we need: http://www.robotshop.com/uk/10a-ac-current-sensor.html

The problem I have is I don't have access to the equipment we are to monitor until we install so I need an (inexpensive) way to reproduce, control and verify an AC current passing through the CT Sensor.

In the live system we will be getting a sharp rise from ~0A to aproximatly 1.2A (aprox 600ms) which should last for about 3 seconds then a sharp drop back down to ~0A. The system will also need to identify when a gradual rise or drop occurs (over 600ms) as this indicates improper operation and so I will also need to simulate this. Something with a dial would be perfect.

Would simply a plug in dimmer switch, plug in electricity meter/current monitor connected to something like a lamp be able to do the job or is there something more suitable?

Thanks

Best Answer

Your basic plan sounds reasonable, But...

I would not recommend a dimmer switch to regulate the current. They chop up the AC waveform, which will stress the RMS calculation part of the sensor, and probably give you inaccurate readings. Rather find a selection of incandescent / halogen light bulbs and connect them one by one.

Note that you can increase the current seen by the sensor, by passing the wire through it a few times. Perhaps don't wind tight coils around it, but if you keep it fairly loose, each time the current passes through the hole it will be counted again. So you can fairly easily and accurately double or quadruple the current from one lightbulb, to try out the full range of the sensor.

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