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anybody have a schematic for a timed output circuit. I am wanting something that will(or I can modify) to send it a single pulse and then adjust the timing on that pulse to control relays. any help would be appreciated. dragnlo@hotmail.com
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I have a couple different ideas on how to implement soemthing like this. What exactly are you doing, how many devices, do you need them in a sequence??? Do you need to be able to tweak the timing and duration?
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I have a couple of projects I am working on the main one right now is for window rollup on a cheap keyless entry system. I want to be able to use a pot to control the time of delay which it is open. For example send it a pulse(door lock) and it sends power out to power up some relays for a certain timebased on the pot. Some of my other projects are for motorization timing where 3-5 events need to happen at certain times. Any help would be appreciated.
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For the window rollup I would say to use a 555 timer to turn on a FET to control the window motor. I don't have any datasheets on the 555 and can't find anything in my textbooks, but they can be used to output a single pulse that the length will be based on a resistor capacitor combination. For the other projects you could use a digital counter to provide the start pulse for a set of 555 timers, one for each pulse you need. That way you could tweak the pulse length, and vary when each pulse starts. There are alot of ways to do this depending on how precise you need the timing.
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You might want to check out Radio Shack. They sell two adjustable timer with relay, that sound like they might work for your project. Even if it doesn't, it might help you in the design of one that will. One part sells for $9.99 and the part number is RSU 12127114. The other sells for $14.99 and is part number RSU 121127148.Good Luck and God Bless.
[This message has been edited by Pegasus1 (edited 05-15-2000).]
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