I bought a “Unibit” type of tapered drill bit from China, a large one. It cuts up to 36mm but the shank is 1/2 inch or 13 mm. I want to put it in a 1/4 inch or 6.5mm chuck. The only drill I have with a half inch chuck is a big hammer drill.
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I’ve been thinking about this for awhile. Let’s say I have a switch, for example a thermal switch that only has contacts that are NC (normally closed) until a certain temperature is reached. At that point, it changes to open, interrupting the circuit. But the input to my controller senses NO (normally open) switch contacts
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I pulled a pill bottle out of my junk box, it had a single layer of solid enameled wire wound on it, and it measured 85 microhenrys. So I added the transistor, resistors and the capacitors to get it to oscillate at the low end of the AM BCB, around 540 kHz. The schem is
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I’ve been getting PC boards that have all the chips operating at 5 volts, but the input voltage has to be between 7 and 12 volts. The board has a 5 volt regulator on the board, and often it is a surface mount chip. But I have dozens of 5 VDC, 1/2 amp AC adapters,
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