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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Posted to FB group 2017 June 8, then a copy here. I found this Radio Shack power supply on Bama.edebris.com. Looks like someone drew it up. I found a few boo-boos, one being the LED having a 100k current limiting resistor. It’s not going to be bright. I wonder if BK1 thermal breaker is capable
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Peter asked a question about why is there a need for two separate power supplies for the same project. I guess it never occurred to me to explain this simply, so everyone can understand it. I have often had to use a separate power supply for one part of a circuit, with a second supply
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There are many circuits that are used infrequently that are powered by the usual 9 volt battery. One of these happens to be a field strength meter (FSM), which is used for detecting the power output of a transmitter such as the one a radio amateur uses. Some FSMs are very simple and use no
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I needed to pick some grapefruit from the tree, and I borrowed the picker pole from a friend. I put it in my Civic and got home, took it out and picked some ruby red grapefruit. Man, were they Delicious! So Monday I got in the car, and CLICK! It wouldn’t start. Then I noticed
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I saw a few items at DX.com that look like they could be very useful. A USB power meter, with even more information in the display, compared to the somewhat lame Practical Power meter. You won’t be caught with a dying cell phone battery with this. It’s a useful addition to your flashlight collection. This
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Earlier this year I bought a cheap cell phone charger for plugging into the car’s cigarette lighter socket. It works, but it’s s-l-o-w. I can drive for a half hour with the cell phone plugged in and it says it’s charging but it only charges a few percent. As a result, I don’t use the
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A friend of mine has taken on the task of finding replacement AC adapters for two laptops, and I thought that I could repair the broken cord on one. But I tried to take the brick apart and damaged it beyond economical repair, so I resorted to the ‘Net to find replacements. He gave me
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Kirk has given me permission to use his picture in this blog. He builds them on Arborite, which is similar to Formica. It looks a lot nicer than the cheap plastic I’ve used. He says: Bottom left is a float charger, top left is a cut out relay circuit, the middle is a battery desulfator,
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Well, the LEDs I ordered more than a month ago have finally arrived. They are 10 Watt(!) 900 lumens from Electronic Goldmine for $6 (USD) apiece (I checked their website and they seem to be sold out). The reason why it took so long was mostly my fault. They were shipped to my previous address,
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