Summary

One day whilst working on some solid modelling, a package from China came across my desk with no discernible or obvious origin, other than the fact that it was addressed to me. Inside were 10 black boxes with 4 wires attached to each. It was peculiar to say the least. Thinking nothing of it, I filed it away on the shelf for future evaluation. Months later, I grabbed the box, and spent some time trying to figure out what they were. I come to find out that they were portable, high voltage generators!

Method:

1. Probed contacts and took resistance readings
2. Googled keywords of “black box, 4 wires”
3. Attempted to search for Chinese characters indicated on side to no avail
4. Returned back to the multimeter and voltage analysis
5. Surmised that the red and yellow leads could be related to a power source
6. Set up power supply with low current cut-off, connected leads to power supply, dial up current limit slowly, and was pleasantly surprised by a brilliant ignition spark

Following this adventure, I made it into a hand held high voltage generator.

Photos

Fig. 1: A quick little hand taser I whipped together using a single 18650 cell, and a button. Has ~2cm spark at maximum, so about ~60kV estimated performance. (30kV/cm for air)