Re: Turntable Stroboscope
I've attached a scan of my circuit (sorry, I don't use CAD, I use a 'paper aided design' system, better known as a pad).
A couple of things : I've not shown the power and ground connections to the ICs, they go to +5V (output of the 7805) and ground. Also add a 100nF disk ceramic capacitor between +5V and ground close to each IC (that is probably overkill when it comes to decoupling but such capacitors are a lot cheaper than my debugging time, at least for a one-off).
The thing runs off a 12v wall-wart type power supply.
There is a 2-pole 3-way switch. Centre position is off. Flipped one way you get 100 flashes/second. The other way you get 120.
The LEDs are on for 1/16th of the time. A short flash (rather than 50:50 on/off ratio) gives a clearer 'still' pattern of the strobe disk.
You are welcome to make this non-commerically. If you start selling them then I feel I deserve something in return.
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