Potentiometer Question.

Thread Starter

ItsAciD

Joined Feb 14, 2013
7
Ok so my voltage source is a external DC Supple, that gives an output of 12V 1.5 Amps. That drives a DC Motor. I want to control the Speed of the DC Motor, however when i connect positive to terminal B, and output to C, The motor does turn on until i reach fully clockwise, and i see a spark, i know thats bad, so i wanted to know how will/can I control the speed of the DC Motor? With a different Pot? The pot I am using is a B10K Pot. Thanks!
 

tracecom

Joined Apr 16, 2010
3,944
Ok so my voltage source is a external DC Supple, that gives an output of 12V 1.5 Amps. That drives a DC Motor. I want to control the Speed of the DC Motor, however when i connect positive to terminal B, and output to C, The motor does turn on until i reach fully clockwise, and i see a spark, i know thats bad, so i wanted to know how will/can I control the speed of the DC Motor? With a different Pot? The pot I am using is a B10K Pot. Thanks!
Your motor apparently draws too much current for the pot. You will need a driver circuit using a transistor that is controlled by a pot. Google DC motor speed control and "read all about it."
 

PatM

Joined Dec 31, 2010
86
Ok so my voltage source is a external DC Supple, that gives an output of 12V 1.5 Amps. That drives a DC Motor. I want to control the Speed of the DC Motor, however when i connect positive to terminal B, and output to C, The motor does turn on until i reach fully clockwise, and i see a spark, i know thats bad, so i wanted to know how will/can I control the speed of the DC Motor? With a different Pot? The pot I am using is a B10K Pot. Thanks!
Your motor apparently draws too much current for the pot. You will need a driver circuit using a transistor that is controlled by a pot. Google DC motor speed control and "read all about it."
You could also try using a wire wound pot with a linear taper and a much lower resistance.
10K is too much for what you are trying to do.
 

Thread Starter

ItsAciD

Joined Feb 14, 2013
7
You could also try using a wire wound pot with a linear taper and a much lower resistance.
10K is too much for what you are trying to do.
But wouldnt i still a spark out of it, because the motor is drawing alot of current?
 

wayneh

Joined Sep 9, 2010
18,183
...because the motor is drawing alot of current?
You need to tell us what the current draw of the motor is. The power supply rating of 1.5A tells nothing about the motor, except that it must not draw much more than that. Pots that can handle much power are usually pretty expensive, and that's why folks build a motor control circuit using cheaper parts. Also, the motor loses torque when turned down by a pot. A PWM controller reduces speed smoothly without as much torque reduction.
 
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