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Help with electronics

Posted: Tue Nov 27, 2007 8:58 pm
by joemama
well im wondering is there a such thing as a relay that can be activated/deactivated by usb?? is usb standard voltage , b/c then i could find a relay for that voltage.

Posted: Tue Nov 27, 2007 11:00 pm
by knappengineering
Just do a quick google search on usb voltage, it took me about 2 seconds to find out that it is 5V, so just get a relay to match it. Remember - google is a powerful tool :wink: :lol: BTW, good luck, I don't know what you are using it for, but it sounds like a fun project. :D

Posted: Tue Nov 27, 2007 11:44 pm
by Killjoy
I think jamco electonics has a little relay/usb controller board, which allows the relays to br controlled form you computer. But like knap said, a usb's volatge is about 5 volts, so almost any realy would do.

Posted: Wed Nov 28, 2007 12:14 am
by TechnoMancer
well you see you'll need a device to decode the USB to turn the relays on and off, and to make them visible to the computer. that is what the relay controller does. If you have ever used micro controllers before and can get one that has a USB interface on it then you can do a lot of stuff with it. what do you want this for? have you had any electronics experience before?

Posted: Wed Nov 28, 2007 12:34 am
by knappengineering
If you don't need it to be controlled by your computer, you can have it just activated when you plug it in, just from the 5v provided by the usb port. And that would eliminate the need for a microcontroller, but it would be awesome to have it controlled by you computer.

Posted: Wed Nov 28, 2007 12:40 am
by TechnoMancer
its not that hard many of the microchip 18f series of micro controllers have USB ports in them but you'd have to learn a language to program it in. C is probably best! then you could do a lot more than just control a relay with it!

Posted: Wed Nov 28, 2007 5:58 am
by TurboSuper
If it were up to me, Id say use an LPT port instead of a USB port.

LPT ports send their data in parallel without any encoding, so basically just tie the relay to one of the data pins (with a reverse-biased diode across it, of course). Then just send FFh to the port.

I won't explain exactly how to do this, since there's oodles of info on Google about it, but it's going to be more difficult to get working on an NT-based O/S (Windows XP, for example).

Posted: Wed Nov 28, 2007 7:30 pm
by joemama
i am bulding a cooling system for my 360 , and lol 5 volts is not nearly enuf , buT i wanted it to turn off and on with the system the answer..... relay!! im gona get an charger that has better outputs 12-16volts soder to wires to it ( getto ) then run it by a relay so it wil turn of and on with the console. tada! lol ,


yea and u guys answerd all my qustions thanx a million