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Electronics => Electronics => Topic started by: sambhav on February 10, 2007, 01:01:34 PM

Title: Driving relays from PIC!!
Post by: sambhav on February 10, 2007, 01:01:34 PM

hiii
i m using PIC 16f877 for my project...
i m using relays in order for switching which are driven
by the PIC outputs.
since the logic 1 for a PIC is 4.3 - 5v with a max current of 25ma
will it be possible to drive relays using such low curr.. if yes.. please ggive me the relay number and other specifications..
i dont want to use amplifiers as it wud add to the circuit complexity..
thanx..

Title: Re: Driving relays from PIC!!
Post by: Hal9000 on February 10, 2007, 01:53:28 PM

Hey there,

I'm sorry if I confused anyone before about the relays that could be driven by the PICs. I haven't tried byself, but i'm sure it's in one of my books............

However, a quick search on google suggested a quick and easy way of doing what you want to do.

http://www.mikroe.com/en/books/picbook/7_05chapter.htm

http://www.technologystudent.com/pics/outin1.htm

You can see, this idea is also used for motors and is the basic idea behind simple H-bridge circuits.

Hope that helped :)

Title: Re: Driving relays from PIC!!
Post by: Admin on February 11, 2007, 03:49:52 PM

check out these posts:
http://www.societyofrobots.com/robotforum/index.php?topic=515.0
http://www.societyofrobots.com/robotforum/index.php?topic=83.0

short story, dont use relays, use MOSFETS. ;D

Title: Re: Driving relays from PIC!!
Post by: Hal9000 on February 12, 2007, 03:39:26 AM

But then, it depends what you need the relays for. FETs instead of Transistiors, don't you mean?

Title: Re: Driving relays from PIC!!
Post by: Hal9000 on February 15, 2007, 03:40:00 AM

Oh right, sorry, driving the relay from the MOSFET. I see.