Web Hosting Talk : Other Forums : Web Hosting Lounge : electronic timer circuit help.

[Fujiwara Takumi]

you guys are a little brighter than the car forums i usually hang out on, and hardforum is down right now, so lemme ask you this question.

i have a item that runs on 12vDC. i need it to be powered for a period of about 5-10 seconds, and then to stop. what should i do to wire up a circuit that will handle this? i would like to press a button and let it power the timer, the timer count down 5-10 secs, and stop powering the device, (incidentally the device are power folding JDM car mirrors). i also want to be able to let go of the button and the timer again power the mirrors for 5-10 secs, and then stop.

right now ive got a relay hooked up that will provide constant power when the button is not depressed, and constant power to another wire when it IS depressed. it is acceptable to me to use two seperate timers for each function

what would you suggest that i can purchase from radio shack?

[platinum]

Your best bet would be to have a sensor which stops when the mirrors are fully out or fully in shouldn't be too hard to sort out with a couple of relays.

If you still want the timer, it should be pretty easy, just grab a 555 Timer IC (I *think* that is the one) and follow the instructions (you'll need a couple of other parts, transistor or two and a couple of resistors + power diode to be safe). Will also need the relays though.

[Fujiwara Takumi]

Originally posted by platinum
Your best bet would be to have a sensor which stops when the mirrors are fully out or fully in shouldn't be too hard to sort out with a couple of relays.

If you still want the timer, it should be pretty easy, just grab a 555 Timer IC (I *think* that is the one) and follow the instructions (you'll need a couple of other parts, transistor or two and a couple of resistors + power diode to be safe). Will also need the relays though.

i dont understand how to find out what the rating is on capacitors, or how to wire a relay. i already explodicated one 555 timer. i should have taken an EE class or two

[platinum]

You won't need capacitors... maybe a nice EE can help out and draw up a circuit for you I have one that would sort of work, but the diagram is not with me here.

Relays though, if you're using automotive ones (the big black ones ) have 5 (sometimes 6) connectors, there should be a diagram on it somewhere, but basically when you wire them up it will take the low current through two inputs, and this will trip the connection between the high current section (the motor for the mirrors).

[Fujiwara Takumi]

the timing diagram i was following required all these capacitors and i dont understand it. also it was asking for these diodes that would somehow keep excess power from building up...but its not something i have the skill level for just yet. i need some direction.