Latest threads in Hobby Electronics Basicsshow only best voted threads
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I got a box of old parts, any chance any of it is useful?
At a fundraising event I found a very nice wood box in the electronics section. It has what appears to be a broken decades old multimeter at the top, and drawers full of parts below. There are a...
7
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4 years ago
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Transistor testing
I have some BC547 transistors which I want to use in a circuit, but according to this: Hook the positive lead from the multimeter to the to the EMITTER (E) of the transistor. Hook the negative meter...
15
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4 years ago
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15 | |
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Wireless phone charger
Just for fun I thought I would make a wireless phone charger. I'm not reall y going to use it but I wanted to build it and just see if it actually work ed. The circuit uses two coils and a 2n222...
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4 years ago
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Does a parrot's foot conduct electricity?
My pet parrot has a habit of chewing wires but never got a shock. I tested her feet with a multimeter and it was over 20Mohms. My own dry finger is 1Mohm. Are they safe from shocks due to scaly feet?
63
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4 years ago
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63 | |
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555 pin3 output
I've been trying out a couple of Automatic Fence Lighting circuits with a 444, 741 and ldr. I posted earlier about the circuits above , and the problem I had was that I could not get a buzzer to work...
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4 years ago
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Problems with 12V and 5V lines on a PC ATX supply
I said "They could even have it shut off if there was enough external load." A decent supply made by Corsair lets you take the full 850W from the 12V line. The designers of this supply are morons.
10
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4 years ago
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10 | |
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Schmitt Triggers
I have been looking at schmitt trigger circuits and didn't realise how many variations there are. Anyway I found this one: The author here says that by adding a 22k resistor to the bottom diagram...
32
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4 years ago
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32 | |
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AoE 3rd Ed heavy discount on Amazon UK
A UK heads up, I had the first edition at college, and sold it on to a new student. Second edition came out, I was still broke so hunted down an old first on eBay. For me third edition now on the way...
9
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4 years ago
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9 | |
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Measuring Accuracy: 1.0 grade
An Amazon meter is described as having "Measuring Accuracy: 1.0 grade". I found that there is a standard that defines the grades, but is there a simple answer to what "1.0 grade" means in percentage?...
3
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4 years ago
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Speaking of 555s...
Recently I added an air cylinder to a manual lathe that opens the half nut when threading by moving the proper lever. For those who don't know a manual lathe that can cut threads has a leadscrew that...
10
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4 years ago
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Engineer's Mini Notebook Series is on-line
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4 years ago
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Basic circuit help please
I have put together a circuit from here: and this is the schematic: I have the led, ldr and the 100k pot part of the circuit working fine, but the buzzer from the 555ic does not work or sound as it is...
64
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4 years ago
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64 | |
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OT History of Carbon
or Deals with the history of carbon and it's uses, as well as refining and smelting of metals, beginning at the dawn of recorded history. An interesting read, and a post-script with links to more.
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4 years ago
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Remote repeater - bit more power to led output
Hi, I'd be grateful for a little advice. I use a tvLINKplus device for repeating the magic eye remote signals which are fed back through the UHF aerial cable to my satellite box. It works OK but the...
3
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4 years ago
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Wattage of rough service incandecent bulbs ??
I have build a series load test light. eg. you plug a load in and it runs i n series through a lamp, in case there is a short, the lamp takes up the lo ad, so as to not blow a fuse. The lamp you use...
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4 years ago
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