Help for a beginner

[AndyNDQ]

Please help, I tried to drive a 9V DC motor using the 2N2222 NPN transistor, but the transistor got burn (probably overpowered). I connected the motor in series with the emmiter, with 9V the going to both the base and collector. Someone had suggest that I connect a diode parallel with the motor, but I got a reading about 0.7 V across the motor, that won't drive the motor. Is the a circuit I can build to drive the motor?

 

[Nigel Goodwin]

Please help, I tried to drive a 9V DC motor using the 2N2222 NPN transistor, but the transistor got burn (probably overpowered). I connected the motor in series with the emmiter, with 9V the going to both the base and collector. Someone had suggest that I connect a diode parallel with the motor, but I got a reading about 0.7 V across the motor, that won't drive the motor. Is the a circuit I can build to drive the motor?

You should have the motor in the collector of the transistor, with the emitter going to 0V. The base should be fed via a resistor from whatever is doing the switching. It's essential to fit a reverse connected diode across the motor, or the back emf will probably kill the transistor.

Try looking at the 'hardware extras' page in my tutorials, the bottom diagram shows how it's done for a relay or motor.

 

[AndyNDQ]

Thank you Nigel, I managed to get it to work using the 2905 PNP transistor. By the way, I can't get to your website, is the link dead? Is this the right one: www.winpicprog.co.uk/pic_tutorial_extras.htm?

 

[Nigel Goodwin]

Thank you Nigel, I managed to get it to work using the 2905 PNP transistor. By the way, I can't get to your website, is the link dead? Is this the right one: www.winpicprog.co.uk/pic_tutorial_extras.htm?

There are two links in my sig, the first is via a web forwarding service, the second is direct - try the second one in case the web forwarding is down!.

 

[AndyNDQ]

My motor is working only if I spin it. What could be the problem? Is the motor bad or is it my circuit? I used a PNP 2905 to drive my motor, with the motor connect at the collector terminal parallel with a reversed diode.

 

[JFDuval]

Hello!

If it start only when you spin it, it's because your motor doesn't receive enough current.

 

[AndyNDQ]

Hello!

If it start only when you spin it, it's because your motor doesn't receive enough current.

Thank you! I lowered my base resistor and then it work perfectly.

 

[JFDuval]

Super!