I built this coil, modeled somewhat after the coil I saw in this Youtube video. It uses 24 AWG solid telephone wire, and the winding color indicates the number of the winding according to the resistor color code: 1 (brown) through 0 (black). The first and last windings are 5 turns each. The windings in
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This remote control jammer circuit is basically the same circuit as a LED flasher, except that the timing capacitor is much smaller – .001 uF – so it flashes at a much higher frequency, around 38,000 times a second. The 9V battery is expensive; instead save money. Change the two IR LEDs from series to
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I had a few really old C cell batteries, the old zinc-carbon or LeClanche type. I tore off the metal jacket and then what was left of the zinc and dirty black powder, leaving the carbon rod, which is used as the positive electrode. I took two of them and held them with a pliers
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I came across this document, The Handyman’s Guide To Understanding Transistor Data Sheets at the NRAO gov’t site. It’s a downloadable .PDF file. This document is great for those wishing to design and build RF and audio amplifiers, but unfortunately it has only a small paragraph at the end on switching, which is what the
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I was discussing using an incandescent lamp for a heater, where the amount of light is not important. I looked up some info on miniature lamps in the General Electric Miniature Lamp Catalog. Miniature lamps used to be inside of appliances, and cars, such as in the instrument panel, speedometer, glove box, etc. Now they
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I had a thermocouple from an appliance lying around in the garage and I decided that it would be a good idea to experiment with it. It was a used one, but I don’t know what it was from; maybe a water heater. But a long time ago I had cut off the end that
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Not me, the beasty I made is the LED abuser. Well, maybe me, too. See the photo. I had this high voltage transformer I got a few years ago, and I hooked up a power transistor (2SC2334) to the center tapped winding just like a Joule Thief. The resistor is 180 ohms wire wound. It
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Remember Capt. Hook and the crocodile? This circuit is almost the same as a flasher, except instead of an LED it uses a speaker. The result is that it pulses the speaker with a very short pulse of current. The circuit uses a 9V battery, but today the 9V battery is too expensive, so I
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I was out working on wiring at our other campus, and was surprised to find that the floor was wired. Yes, the floor was wired. Well, the floor had wiring on it. This was for the class where they teach robotics and the wire is there for the robot cars to follow. I haven’t investigated
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