Transistors and DC Motors

Community PCB Design
1

I’ve built a circuit to use a transistor as a switch to run a small DC motor. This is all in SMD. I mention this because when I created it on a breadboard with through the hole parts the motor ran much faster. My circuit works, it’s just not running the motor fast enough in the SMD incarnation.

The issue is that I need to motor to “burst” on, have more power when the circuit is built with SMD parts, powered off of a 3.7v, 250mAh battery… I’m fairly sure it means I need more voltage passing from the switch tranistor to the motor…

So my question is, should I use another transistor as an amplifier (after my switch transistor) to boost the power to the motor? Would that make sense? Would a capacitor be better? Clearly I’m not an EE, I’m a hobbyist.

Thank you!!

2

If you have a volt meter, measure the voltage at the motor terminals, once with the SMD build and again with the breadboard. Is the transistor on the SMD getting hot?

3

That’s a great idea! I’ll have to rebuild the circuit on the breadboard, but at least I’ll know how many volts are being passed in both cases! Thank you!