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Optical Buttons?

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ShinAce:

It works great. I'm buffering the signal with a schmitt inverter. The part number for that is 74ls14. I'm using a 54hc14, which is the same thing but in military specification.
Nearly everything worked out perfectly from the get go. At first, medium punch would jam, but then I realized it was because of the inverter. It'll switch when you get past, say, 2 volts, but won't switch back until you get below a volt. It turns out the medium punch LED was a little off center, so I bent it in place and off I went.

It doesn't feel awkward for me, it's kind of nice. Quiet, too. Just remove the microswitch from a pushbutton and that's what it's like.

IntruderAlert:

now all you need to do is start mass production and distribution

..and don't forget to get your patent ;)

ShinAce:

I could build the optical switches, and they can be directly plugged to a pad, as long as you give them 5 volt power. But since I'm using the schmitt trigger as a switch debouncer, the whole situation becomes more complicated.

But if someone wants to try it on their own, they'll need an OP550(A or B or C or D), I used the OP550A as well as some high intensity red LED's. Add an unwanted microswitch and 2 resistors, and you're done. The microswitch should be free, since you don't need a working one. The resistors are worth roughly 5 cents each, the led is worth about 25 cents, and the photo-transistors are 1$ each. So it cost me under 2$ per switch, assuming an unlimited supply of free microswitches.

spiffyshoes:

Where would you suggest getting the parts?  And could you make a tutorial on what needs to be done to the microswitch to add these and how to hook them up to a pad.  I'd assume you could hook them up the same way you do a P360 just supply the +5v from the pad and then the ground and live wires like normal.

ShinAce:

You can get the high intensity red led's, 1k resistors, 10k resistors at any local electronics store. The OP550A can be had from digi-key, mouser, or possibly fry's. I got mine locally for 1,25$ a piece, canadian.

The way the circuit is wired, it's backwards. So it would work properly if you held all buttons and let go of the one you want pressed. So I fixed this problem and debouced the switch in one shot. I used a 74ls14(or 7414, or 74hc14, even 54hc14) to invert the signal and keep the switch from having a strobe effect when held halfway. In a pinch, you can use a 74ls04, but it doesn't eliminate the bouncing effect(in theory at least).

The one it's done in the pictures, COM is 5 volt, NO is the active signal, and NC is ground. You can rewire it if need be, but for the pieces I had, this placement was ideal.

www.geocities.com/alainprice/opticmod.zip

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