This is a brief one. After my clothes dryer arduino sensor, I quickly realised I wanted to determine when my dryer was powered on. I didn't want to modify the dryer itself, so started to look as passively sensing when the dryer was turned on. To do this I looked at the clamp-meter method of determining current flow. (I use this for my electricity consumption for the entire house, but using a commercial product).
Checking various websites I found that this was something that could be made with some success, so I started to look for the relevant parts. I had spare copper wire, a spare caribena and set about it. The result was this:
As you can see I had to use a couple of different wires that I joined. But the basic principle remains. I could hook this around one of the two feeds to the dryer (Only live or neutral, round both cause a cancellation effect) and then read the millivolts induced by the crude 'transformer' I have made.
However, no luck. I re-wrapped this several times, tried different methods and different ways of connecting it up and no matter what I tried I never got any output on my multi-meter.
So here it is. What have I done wrong, or how could I improve my design to make this work?