CIRCUITPLAYGROUND CLASSIC- DC MOTOR INTERFACE

[bmink1234]

I have been struggling to get my Classic Circuitplayground to work with a small toy 3V DC motor. I connect pin 2 to base of NPN transistor (through a 1k resistor)and emitter to ground. Collector to one side of motor. Positive side of motor going to external battery pack +3VDC. External Battery pack negative connects to GND of CircuitPlayground. CircuitPlayground is powered by USB cable. I also have a flyback diode across dc Motor. The motor does not come on. When I replace the motor with a sequin LED it works perfectly and is very bright so I know my code and transistor is working just fine. The DC motor works just fine when powered directly across the 3VDC battery supply. Any ideas why this doesn't work?
I am using a 2N3904 NPN transistor and a 1N4001 diode. Resistor from Circuit Playground to base of transistor is 1k.
See the link below to see how I have connected everything up.
https://techexplorations.com/guides/ard ... ransistor/

[adafruit_support_bill]

Does the motor show any signs of trying to move? If you give it a spin by hand does it keep on going?

[bmink1234]

Nope. I gave it a little push..nothing..dead as can be.

[bmink1234]

Perhaps I should get a multimeter out and check the amount of current going through the emitter to ground as it is configured now.. And then check the current when I connect just the fan and the battery pack (2 x 1.5V AA batteries). Maybe the transistor emitter to ground is not getting enough current?

[adafruit_support_bill]

Some current measurements would be helpful. The 2N3904 is only rated for about 200mA. That may be sufficient to keep a small motor running. But the startup current is typically several times higher.

[bmink1234]

Thanks. I will check it out tomorrow.

[bmink1234]

So I found the DC motor was drawing way more current than I expected.. like well over 500mA. I don't have another transistor so I ended up just ditching the original DC motor in favor of a small brushless motor/fan. Hooked it up instead of the motor and everything is working well now.
Hooked up fan similar to the link shown here. https://web.cecs.pdx.edu/~gerry/class/I ... ernal/fan/

[adafruit_support_bill]

Good to hear you found a combination that works. Thanks for the follow-up.