Pic to relay

[ruijc]

Greetings to all,

Newbie and my first post here...

To short things out here is the thing:

i have a circuit that uses a 16f84A pic and one of the I/O is ment to turn on and off an external circuit.

For this i thought first of using a relay but turns out the coil draws too much amps and the pic does not handle it very well.

My second though was a 5v solid state relay...but at my local shop they do not have any ...

Is there a way to do this with other components ( i mean...easy to get components ) ?

thanks
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[Luciano]

Hi,

See this link:
http://www.rentron.com/PIC16F84.htm

Best regards,

Luciano

[ruijc]

Thanks,

will try this.

my best regards
rui

[spuffock]

A logic level FET is a nice solution, only one component needed. Use an N-channel device, source goes to ground, gate to the output pin of the PIC, drain to the relay coil. Other side of relay coil to +5v. Be sure to connect a diode across the relay coil to deal with bach EMF, or you will destroy thr FET the first time you switch off.
If you do not need the isolation of a relay, power FET' s will handle a lot of current- tens of amps is common.
Best of luck!

[ruijc]

I have tryed it and it works more than fine !

thanks to all !

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