I'm working on project 9 of the arduino starter-kit - the motorized pinwheel.
Here is the schematic:
The diode in question (and the only one here) is toward the bottom right of the breadboard. It is to prevent the back-voltage from the motor from harming the circuit.
According to the above img, would the backvoltage travel back down the motor's supply of energy (the red wire)?
If so, what is the diode preventing here? That whole energy strip will just have current running through it and the diode's cathode will prevent it from running to the transistor - which would also happen fi we just didn't connect anything to that power strip.
If not, and the back-voltage is running through the black wire (our ground), then I still do not see how the diode is helping. The diode seems to want to pull the extra energy back to our power strip (which is why the anode is facing toward the left, where the motor's output is. But this doesn't prevent the current from still hitting the green wire which leads to the transistor's 'source'.
So how is this diode working?