Potentiometers (Pots) - Electronics Basics 25 

Mumbo jumbo

Exactly

not great video

They are the same thing, trim pots are just made for precision

A potentiometer is not a polarized component. And yes, 3 pins are used to create a divider, splitting the voltage between two pins

thanks

I'm actually working on a circuit right now and I grabbed a random potentiometer so idk what its resistance range is, but I have it connected to a 9v battery and a dc motor (unknown specs as well) and connected the middle pin and one of the side pins to the circuit. However the motor only turns on when I have the knob of the potentiometer positioned at its max position, when I turn the knob away the motor instantly turns off, it doesnt slow down or anything. Could you possibly explain this?

its better on EveryCircuit

Watch the video again: The wire connected to the "wiper" is the output. How would anything be output if not for another wire to input something? It's not as if the "pot" creates current "out of thin air"! The third wire goes to ground. The whole idea of the pot is to divide what is input between the output & ground: If the wipe is at the start of the carbon track closest to the input wire, all of the current avoids the track and passes into the wiper & out...no resistance. When the wiper is situated at the other end of the track, everything going out the output wire is exposed to a resistance equal to the value of the pot, and the rest goes out the ground. So, there must be 3 wires: in, main output & ground. Consider that the same amount of current flows regardless of whether if ends of going out the output or goes to ground. Theoretically, a resistor can work without a ground, but then the total current flowing thru it would be only what goes out the output. The effect on the circuit would be very different.

Very inefficient way of varying speed to a motor. You can do it but you'd need a high power potentiometer to do it. DC motors are usually controlled using pwm to vary the voltage to the armature.

Your question does not make sense. Perhaps if you could rephrase i will try to answer.

Fair enough, what refference does one use to calculate the value on a potentiometer? - The Pot comes with a value right?! 1K, 100K, 500K... is this value its max, min or avg. Thanks.. hope I made it somewhat clear, not english spoken here.

Much better phrased. The value of a potentiometer is based on its max resistance. So a 10k pot has a max value of 10k. Min value of all pots are usually 0Ω.

Dumb quenstion right?! Thanks again, hope you keep uploading soon

+David Sanchez the only dumb question is the one that isn't asked. You are welcome my friend.

There is none. However a potentiometer becomes a rheostat when the middle pin is connected to one of the other pins. Edit: actually a Rheostat and a variable resistor are the same apparently. Edit Edit: I have no Idea anymore