External power supply

I have a pump that requires 8-16V to run. The Arduino Uno and Arduino Mega board only supplies a 5V output. How would I power the pump while still controlling it with the Arduino?


You need a "driver" between the Arduino and the pump. If the pump only needs to be ON or OFF and run in one direction the simplest thing may be to use a relay that is switched by the Arduino. If the pump needs speed control but only in one direction then a MOSFET would be suitable. If you need bi-directional speed control then you need a H-Bridge driver.

Whatever you choose it has to be selected so that it can handle the stall current of the pump motor. Pumps. especially, draw a lot of current at startup.

If you need more advice post a link to the datasheet for the pump.

Note that many high-current relays will not be suitable for direct connection to an Arduino - you will need a transistor between the Arduino and the relay coils.