Just few experiments in Mythbusters style. It is funny experiments with short circuits, high currents, flames and fumes. The voltage is lowered, but current is more than 200A.
The test device schematics looks like this: welding transformer with fuse and thermal protection on high voltage side. On lower side are rectifier, capacitor, voltmeter and shunt to measure current. The shunt is too weak for these experiments- the current is more than 200A.
The “schematics” before experiment:
The victim- 4 square mm copper wire with PVC isolation (~AWG 10…12).
This experiment is unfinished, as the copper wire didn’t melted- the automatic fuse box triggered and disconnected mains. This means, that the current in 230V side was much more than 25A for a long time.
Here is short movie of the experiment: XVid, 670kb. With sound. take a note how wires jumps from magnetic flux caused by high current.
Next experiment with thinner wire. It is about 1 square millimeter solid copper wire (AWG 16) with triple insulation. This special insulation is with filler to stop fire.
The wire melted near connector. The short movie of the experiment: XVid, 670kb. Highly recommended to see the movie with sound.
Ant the last experiment in this day. This is standard tape recorder’s mains cable. With power rating printed on the connector: 230V, 2,5A.
Interesting fact, that short time before destruction, this cable managed to pass 70A current…
Movie of the last experiment: XVid, 670kb, sound is mandatory for this movie. You must feel the power of the blast.