A pic circuit as a "switch" on a higher voltage circuit?

Hi again all!

Say i have a really simple circuit.

Just a 9v battery, to a 9v motor.

And i want to use a pic circuit to control this circuit how would i do it?


http://premium1.uploadit.org/itsall3//cheapDesin.GIF

So my simple pic circuit running allowing the current to pass through the higher voltage circuit only when the leg is "high"
(sorry about the crap diagram, but hopefully it shows 2 seperate circuits, with the 5v one controlling the 9v one)


Many thanks.

guest_05, I would use an NPN transistor with the Collector connected to the lamp and the Emitter connected to the Negative of the 9 volt battery. The Base of the transistor would have a resistor of about 1000 Ohms to the PIB output pin. Also you NEED a Common ground path between the 5 volt source and the 9 volt source.

Dave Purola,
N8NTA

Hi,
you can use an NPN or PNP transistor as a switch.the number of the transistor is depends on the current that your motor need.and also you you can use 74HC4066(analoge switch) but it is depends on your motor current.
you can use 7805 regulator to have the 5 volt regulated voltage .
you should connect the 9 volt to the input and connect the ground to the middle pin and take the 5 volt from output of the ic.

wow, cheers for the replies guys, but you are both way over my head :(

--- i've only just finished my first circuit of blinking an led lol


Basicly, i cannot do anything with the 9v circuit, i just used that as an example, i'm really using a 12v torch on a boat.

I dont want to really join the two circuits up, except for unsoldering the switch on the torch, and adding a single component in to act as the switch.

Then my pic circuit will be able to do simple flahses of the torch, such as "SOS" etc.

Many thanks.