Vilros Circuit #10 Understanding

I’ve been working on Circuit #10 of the Vilros Ultimate Starter Kit. The goal of this circuit is to make a motor turn. I’ve attached a picture of what the circuit should look like and what I did. Mine does not work.

I tried solutions that worked for others on this forum:

  1. using 10k ohm resistor instead of a 330 ohm resistor
  2. turning the resistor in a 180 direction so the collector and emulator are switched

Neither of these solutions worked for me. If you can see what is wrong with this circuit that would be appreciated! However, if I could understand this circuit more that would be just as great.

Specific Question:

  1. From my understanding of this circuit, the motor is receiving a two positive charges instead of a positive and negative charge, why?

Note: When I gave the motor a positive and negative charge the motor turned without stopping, but the code did not work with the motor. For example, the code has a method that allows the motor to turn on and off, but the motor just continued to turn without stopping.




I've been working on Circuit #10 of the Vilros Ultimate Starter Kit.

Not everyone has this, show us a image of the circuit.


  1. it is not. The motor gets the positive signal on the red wire and the yellow wire goes to the transistor. This acts like a switch and connects the yellow wire to ground when the Arduino output pin is high.

That circuit will work if you build it right and the components, especially the transistor are not burnt out. Make sure that diode is the right way round, note where the bar is at one end.
The first photo was useful, the other two of random wires sticking out of a bread board are totally useless. Unless we can see all the wiring you just can't tell what is going on.

Check your circuit with a LED and a small resistor (100-330 Ohm) instead of the motor. If you cannot change the brightness, detach the resistor from the Arduino, and apply +5V (should burn) and Gnd (should be off). If this does not work, reverse the transistor, or better look up the transistor pins in its datasheet. If this does not help, use another transistor.

If you reversed the diode in your experiments, this might have killed the transistor.

I did in fact reverse the diode, so I probably killed my transistor. Also, thank you for the explanation! That makes sense.