I definitely need a refresher on electronics and creating circuits as I am having issues with controller the speed of my DC motor.
I believe I have to add some resistance to my circuit otherwise my pot will start smoking (which it has already :') )
I'm not sure how much resistance to add or where to add it to control my motor.
Right now I have positive terminal of the pot to positive rail of the breadboard, center pin to one of the dc motors terminals, and nothing for the third pin. Then of course I have the positive and negative terminals of the battery on the respective rails of the breadboard.. but when I adjusted the speed, it started to smoke..
Please let me know if you have an idea of how I should fix this -- thanks!
As Grumpy_Mike said, it cannot be fixed with the parts you have.
Lets look at what you are asking for a moment.
The motor has a current range of 0.3 A no load to 1.43 amps full load. So we will look more closely at a moderate load of 0.5A.
Now none of these calculations are linear so the simple example is only an estimate but it is close enough for you to see the concept.
Starting with 4.5 V power and a 0.5A motor with a moderate load.
Say you want to slow the motor down to 3.0V. The resistor needed would be:
R = Volts/current
R= (4.5 - 3.0)/0.5
R= 3 ohms
The power dissipated in the resistor is:
P= IIR
P= 0.50.53
P= 0.75 watts
You would need a resistor capable of 2 X the power so it doen't overheat. That would be 1.5 Watts
The little bitty end of your 50K ohm pot cannot do the job.
The part I left out for clarity is the current will change with load, so the voltage will change with load causing the motor speed will change with load (a lot).
