I have a microbit setup with a relay controlled by pin 0. The relay is being used to turn on a simple motor. Everything works fine when the motor is connected to a separate 3v power source, but if I try use the gnd and 3v outputs of the microbit to power the motor the microbit immediately resets once the relay switches on.
These are my connections to the relay: Microbit 3v > relay DC+ Microbit gnd > relay DC- Microbit p0 > relay IN
This fails: Microbit 3v > relay NC > relay com > motor > microbit gnd
This works: 3v battery + > relay NC > relay com > motor > 3v battery -
I have tried adding a resistor in the path, but the smallest I have is 170 ohm which is too much to power the motor.