I'm conducting an experiment for my Physics class. I'm testing different transformer cores and comparing the transmission efficiencies.
For my circuit, I have a variable autotransformer connected to a receptacle. From there, I'm measuring AC current with a multimeter in series with the hot wire which then connects to one of the lead wires of my primary, and my other lead wire is connected to neutral. I also have another multimeter in parallel across both connections for an AC voltage reading.
This is a step-down transformer with a winding ratio of 2:1. On the secondary side, it's the same setup as with the primary. I have a multimeter in series with one of the secondary lead wires and am measuring the current. That then connects to the load which is a small, low-power bulb that you find in car headlights, so 12 V and less than 2 A. After that it goes to the other lead wire on the secondary, again with a multimeter in parallel reading the AC voltage.
When I started testing, I was getting no power through. The secondary side was 0 A and 0 V, while on the primary it was 0 A and 20 V.
The transformer wasn't vibrating so I knew no power was going through.
When I disconnected the multimeter reading current on the primary side and did straight connections, power went through and I was getting readings on the secondary, but it was about 0.2 A and 1 V on the secondary with the primary running about 5 V to 10 V maybe. The light bulb (load) wasn't lighting up, and when I started stepping up the voltage on the primary through the autotransformer, it started smoking so the insulation on the copper wires must have been burning.
I don't have a current reading on the primary because it didn't work when I first tried it out, but I know it must have been a high current because it was burning the insulation. I don't know why there's a high current in the primary to begin with when my load doesn't require high voltage or current.
Please give me any ideas or solutions.
