Motor Behaving Strangely

Hi, I'm doing a simple dc motor circuit where a transistor is triggered by a digital pin which connects the motor to ground. The power is supplied by a 9 volt battery. I tested the circuit with a motor and it worked fine. But then, I hooked it up to the motor that is driving a car, and it doesn't work. And the weird thing is, the motor works when the transistor is powered straight from 5V on the Arduino. I don't know why the 5V from the digital pin is different from the 5V straight output.


The small rectangular 9V batteries are for smoke alarms, not motors.
You should NEVER attempt to power a motor from either a digital pin or the Arduino 5V output.

Use a battery pack or power supply for the motor, and connect the negative lead of the motor power supply to the Arduino ground.

The battery pack is powering the motor, the arduino is just triggering the base pin of the transistor.

What transistor, base resistor and motor are you using?

Can you post a picture of your project please?

Can you please post a copy of your complete circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Thanks.. Tom... :slight_smile: