Hello, I am working on school project dealing with a mechanical speed control for a RC car. If you do not know, mechanical speed controls are not very efficient, they waste a lot of power in the Resistance component of the speed control. I am trying to come up with replacement to the ceramic resistor. The replacement needs to be more efficient and not overheat. (I am considering using a Electronic Speed controller.) Can anyone give me some ideas on how i can configure a circuit to replace the resistor and make it not produce as much heat as the current resistor.
Mechanical speed controls are nothing more than a multi-position switch wired to a large ceramic resistor with a heat sink. The resistor helps create 3 speeds for forward and 2 speeds for reverse. The resistor has 3 leads. You can see a picture of the resistor at (http://www.dansdata.com/images/ta04/spdcont400.jpg). When you go at slow speed the whole resistor is used, when you go at medium speed, half the resistor is used and when you go at full speed, the resistor is bypassed.
You must address the problem in your circuit first. If a resistor is overheating, there is too much current flow though it. You must match the resistor to the circuit requirements, or adjust the source or load to match the resistor capabilities.