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Logic gates-I think

Bob

#4380

Logic gates-I think | 21 April, 2000

I'm working on a project that requires that I analyze a signal from the parallel port of my computer and use it to turn on relays. There are about 19 relays to control, and I designed all the gates to get each one on, but there is a problem with keeping them on when I output to turn on another relay. Ideally, here is what I want:

pins 1 and 2 control one relay(not really, but for ease in explanation, they do). pin 1 is high and pin 2 is low. The pins both go to some gate and the output is low. Now turn pin 2 high, and the gate output is high. Now turn pin 2 low and the gate output remains high. Finally, turn pin 1 low and the gate output goes low. Thus, pin 1 controls whether or not it will work at all, and pin 2 only initiates it but will let it continue to work when turned off.

I've been wracking my brain for ways to get this to work and I'm stumped. Please help if you have any suggestions.

bob

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Bob

#4381

I fixed it, but am having a new problem | 24 April, 2000

I figured out how to do the first one (I used a multiplexer with addressable latch--works like a charm) Really, it's perfect.

My new problem, though, is using this signal to get a string of lightbulbs on. Is a relay what I need? If so, who makes a relay with a small current to turn it on, but can carry a huge load?

Thanks in advance,

bob

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#4382

Re: I fixed it, but am having a new problem | 24 April, 2000

Bob: I can't help you. May be We-Man can. Good luck. Dave

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