Switch pic micro ON/OFF with output signal from another pic

[pasicr]

2n3904 switch pic

Hi,
I need help about this hardware solution,
I use two pic micro (16f628). One of them is allways in ON condition. I need switch ON/OFF power supply on second pic with output signal from the first pic. (this pic work from time to time, depends of condition on first pic).
Please anybody if you have any idea send me info, what can I use, reley, switch transistor, or something else?
regards

 

[3v0]

Re: Switch pic micro ON/OFF with output signal from another

A 2N3904 transistor works well as a switch.

Connect the base of the transistor to the output pin of the first processor.
Connect the collector to the +5.
Connect the emitter to the pin that powers the 2nd pic.

You will have a voltage drop of about .7 volts so you will end up with a bit less then 5 volts to run the 2nd PIC. If you feel you need the full 5V either setup a 6V supply to switch via the transistor or drive a relay with the transistor.

The 2N3904 should drive up to 200 mA.

If you want to see some circuits look at the blog h**p://leehow.blogspot.com/
and read the topic "Driving 5V relays".

3v0