Driving a 180ma relay from PIC port

[Michael]

Thanks.

I need to stock up on a good general purpose FET so I'll grab some NDS7002.

I would like to keep my relay from drawing through the regulator, so I'll breadboard something.

As they say in Indiana....Cheers.

[jamie_s]

I have always used bd681 with a 1k on the base, supports upto 3 or 4 amps with a heatsink.
Emitter to ground and load between + and collector. if driving a relay, then put a 1n4004 across the transistor

[Ioannis]

I just poped-in the thread and I bet the problem in the first place was the reseting of the PIC. So as very good stated by Alain the circuit should have good decoupling on the 317 and the PIC. The coil of 180mA sure spikes hard!

Every regulator need large capacitors on the in and out pins! Do not forget it!

The transistors like the ones refered are enough to drive the relay. Also add to the list the BC337 (0.5A/45V)

Ioannis

[jamie_s]

My supply circuits are generally as shown in the dodgey mspaint attachment.

This only powers the pic, any other devices ie relays etc are powered from the source or seperate regulators. I use this circuit in automotive projects without issue.

[mister_e]

100 uF at the output might be high and loose some fast spikes, i would add 10uF tantalum on input and output as well. At the input you can use higher than 100uF.

Without having the whole thing here, it's hard to find the best suggestion. Many nice tips have already been said.

[Pic_User]

Hi Michael,
How did the new transistors work out?
-Adam-