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.

Avocado vs high pressure nitrous oxide

Chris Agerton (http://www.youtube.com/user/cagerton) suggested that I try adding nitrous oxide bubbles to an avocado -- a wonderful idea since avocados are fatty, and the gas should readily dissolve in the fat. I placed some avocado slices in my pressure chamber and dispensed two nitrous cartridges into the chamber. I let it sit for about 7 hours. I then took the slices out, and reduced the pressure with a vacuum pump. Unfortunately, the avocado was resistant to the nitrous infusion process. I will try again with guacamole and shaking/stirring to encourage gas absorption.

Whipped chocolate made with high pressure nitrous oxide

I made some whipped chocolate by melting standard semi-sweet morsels, and applying nitrous oxide at 250 psi. I then dispensed the melted, gassified chocolate into a chilled vacuum chamber, then applied a vacuum to create large bubbles within the chocolate. I maintained the vacuum level while the chocolate solidified with the bubbles still intact. This process yields a dessert that is very low-density, and has a very pleasant airy texture.

Simple cloud chamber

A cloud chamber shows alpha particles being emitted from americium sources. The chamber works by creating a layer of supersaturated alcohol vapor which visualize the radation. The alpha particles trigger condensation in trails through the vapor cloud and show up as tiny droplet tracks. In this chamber, I have two alcohol-soaked pads above an aluminum plate that is cooled by dry ice. The pads emit alcohol vapor, which is cooled by the air above the aluminum plate to the point where it is colder than would normally by necessary to condense. The tiny radioactive particle pushes it over the edge to cause condensation, which is visible droplets.