Electronics Using PIC to Control > 5V

Sorry guys, it's been a while since I've been here, but this problem is killing me. For the sake of clarity, I have a circuit that runs off of a 9v battery (8.5v in reality, somewhere around there). I also use a linear regulator to lower the voltage enough to run a PIC16F628, but I'd like to drive some motors at that 9v using the outputs from the PIC which are around 4.5-5v. Is there some way to do this? Transistors don't appear to work, relays are too slow for what I'm trying to do... Any ideas?

Thanks in Advance!,
Stefan

 

BS. how are you using them?

 

Ordinary BJ Transistors or FETs will certainly do the job just fine, if used correctly.

 

Here is an absolutely terrible and crude whiteboard drawing of what I'm getting at. There's a little arrow and question next to where it should be rather high voltage (I guess 8.3v). Anyone help would be appreciated, this probably sounds rediculous and it is, but I'm clueless.

Thanks!

 

My rough copy.

 

You can connect the transistor collector to +9V via the 10k resistor, and connect emitter to ground. Thus, the collector is held at 9V while the input to the base circuit is 0V, and 0V output at the collector when the input to the base goes high. This config. should work OK with an NPN transistor.

 

Thanks for your help. I've gotta hit the hay (dorm rooms and roommates, cramping my style), but I'll be sure to try it in the morning. Thanks a bunch!

 

The circuit you show is for a transistor as an emitter-follower, where the emitter voltage is always 0.7V below the base voltage. And base voltage is the PIC 'high' output (5V) less a fair voltage dropped across your 10k base resistor (which isn't needed with an emitter-follower) so the load doesn't get to see a deal.

KV2's diagram is correct, but the base resistor may be a bit high. 4k7 will limit base current to about 1mA, limiting load current to (transistor gain) mA.