BLOW UP A BAM BOARD.
Circuit boards that control high voltage at high current tend to be prone to rather spectacular failure due to the avalanche effect of plasma and tracks. Basically speaking, when a short circuit occurs the flimsy PCB tracks will tend to blow like fuses, and when they do they erupt in a ball of conductive metal plasma that engulfs the adjacent area of the PCB and shorts out further tracks causing them to blow too. The result is a circuit board that just completely blows up and copper plates anything in the direct vicinity. Having just initiated such an event with the tip of a screwdriver (not for the first time) I found the incident so amusing that I built a special board just for blowing up. It's called the BAM board.
The BAM board is a circuit board that is designed to fail in a spectacular and uncontrolled manner when it experiences a short circuit. It's not too hard to create a short circuit scenario given that the distance between high voltage tracks on the board is less than a millimetre. :-)
The BAM board is simply two interleaved combs of tracks connected directly to the mains supply. When powered up and then shorted, the slim tracks fail and cause the carnage to spread until it blows itself clear.
Here's the BAM board with it's interleaving tracks tastefully embellished with the text "BAM BOARD" spelled out through varying the track width.
This shows the interleaving and the track detail.
I didn't expect to get this picture, since I thought my timing with the camera would be way off. I set it to self timer mode and then counted the beeps to find out when to drop a steel Pachinko ball onto the PCB. As it transpired I did manage to catch the explosion right at it's commencement with the sparks flying off the PCB and a very visible burst of plasma errupting from the tracks. Note how the area that failed first has initiated a secondary failure where a metal laden spark has landed on another part of the PCB.
The area of the board destroyed is dependent on the behaviour of the plasma and the time it takes for the circuit to trip. A circuit breaker responds much faster than a fuse, so the fuse is the prefered option for absolute copper carnage.
This is a close up of one of the bus bars, showing how the copper has been blown off the board.
I'm not going to put up an artwork file for this PCB since it's a straightforward design you can rattle up on a PCB CAD package in no time, and I'm not convinced that many people will want to go to the hassle of making a PCB that will be destroyed on it's first use.
There's also a liability issue with the concept since the design is rather dubious in it's nature. Obviously it would be very foolish to make a BAM board, so the risk is entirely yours. :-)