Friday, September 16, 2016

High Voltage Anti-Gravity

You can rub a balloon on your head and pick up little bits of paper using the static charge but can you move anything else in this way? Placing a lit candle on top of my Van De Graaff generator does something interesting, it completely takes the charge away, when you touch the terminal there is no spark at all. The hot gases in the flame are slightly conductive, which to a low current, high voltage power supply, means it is effectively a dead short to ground. So what happens when I blow the candle out?

With the flame gone, charge begins to collect on the surface of the terminal. After the charge reaches a critical value the liquid wax, which has been charged along with terminal, is repelled so strongly that it creeps up the wick and the sides of the candle, eventually forming sharp points. Wax then jumps off these liquid point as streams of micro-droplets which fly across the room and stick to the nearest grounded object. If a grounded surface is brought near by the wax will jump to it, losing its charge. Once discharged the wax becomes attracted to the Van De Graaff and it will jump back.

Another interesting behavior happens when only one wax point forms, the stream of micro droplets will fly a meter up into the air and occasionally orbit around grounded objects before making contact or falling to the ground. I have yet to catch this on film but it is on my 'todo list.'


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