A capacitor is used to produce an extremely high (but short lived) current around a tin can. This sudden change in flux causes an opposing current to be set up in the tin can. This current, acted on by the original magnetic field set up by the coil, causes a strong Lorentz force to be experience around the circumference of the can, evenly crushing the can inwards.
This demonstration shows the action of Lorentz force in a dramatic fashion. This also effectively illustrates how energy can be stored in capacitors and can also be used to talk about RC circuits. (as an example of an RC circuit with a very short time constant.)
Place wooden platform over the PVC pipes covering the capacitor ends. This part is tricky, you can't 'slot' the platform on, it needs to be lifted and lowered onto the PVC pipes from above. Attach the switch and coil to the capacitor leads as pictured below. Place the can inside the coil. If necessary, it can be fixed in place with some tape.
Once everything is hooked up, you're ready to run the demonstration.
The instructions below are also included on top of the 3kV power supply.
High voltage and a dangerous capacitor is used in this demo! Please ask for assistance from demo personnel if you have not operated this before. Always short the capacitor using the copper rod before touching anything with your hands to make sure it is fully discharged. Assume everything is at high voltage until proven otherwise.
Top view of the can crushing apparatus. Bottom left inside the acrylic box is the solenoid which, when energized, completes the circuit. The terminals are shorted in this picture, this shows how it should be stored.
Demo room information
|Location||Q1, requires big bang capacitor|