Attempting to make X-rays by unrolling Scotch tape (negative result)

A few years ago, a research group posted a video showing that X-rays could be created by unrolling scotch tape in a vacuum. The idea is that the static charge generated by the mechanical unrolling process would cause electrons to accelerate to 50KV (or so), and then produce x-rays when they slam into something. I tried to recreate this experiment, but I had pretty weak results. I may need a much larger vacuum pump to keep the pressure in the chamber very low while unrolling.

Creating X-rays with a standard vacuum tube

I forced an RCA 811A tube to produce some X-rays by operating the tube in cold-cathode mode at about 20KV and 150uA.  The glass fluoresces nicely, but I didn't get any light from my X-ray intensifier cassette.

MightyOhm's geiger counter kit: http://mightyohm.com/blog/products/geiger-counter/

Frying a potato chip in Fluorinert FC-40

I recently bought some Fluorinert FC-40 on eBay since it is such an intriguing chemical. This fluid is 1.8 times as dense as water, but has almost the same viscosity. It is also very inert, has a boiling point of 160*C, is immiscible with water, and has exceptionally low electrical conductivity. The fluid can dissolve large amounts of gas and was shown in the movie The Abyss where it allowed a rat (and later a human!) to breath the oxygenated fluid, by submerging the rat in  a container of Fluorinert and having the rat take the fluid into its lungs.

Measuring the voltage and current of a microwave oven magnetron

I took apart my microwave oven and measured the voltage and current supplied to the magnetron. The device appears to start conducting current at 4KV, and will allow lots of current to flow once this threshold voltage is reached.

My current probe is pretty cheapo, so I wouldn't trust its measurement too much, but the final determination of 1300 W average seems pretty spot-on.

Liquid level sensor and controller (auto top-off for aquarium)

I built a liquid level controller that senses the level of water in my aquarium and powers a water pump when necessary to compensate for evaporated water. This is known as an "automatic top-off" system. The controller is based around a Keyence FS-V11, which sends light out a plastic fiberoptic, and measures the amount received via another fiberoptic. The optical probe makes use of total internal reflection to control how much light is returned to the Keyence based on how far the probe is immersed in the water. It is also completely passive, non-metallic, and has no moving parts for high reliability. The Keyence triggers a solid state relay that supplies power to a standard AC outlet. The pump is then plugged into the outlet, and moves water from a reservoir into the aquarium on command.