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PWM Speed Controller for Robots. Click here

Since we now have a pretty good idea of the amount of current our motors will need, we need some way to be able to control the speed of the motors. In the early days of combat robotics, many builders controlled the motors in their bots using combinations of relays, solenoids, switches and servomotors to control the power going to the motors. The use of servo motors with electrical switches is call “Servo Switching”, this allowed builders to use high current motors but these systems can be un-reliable, complex and only allowed motors to be run in full forward, stop or full reverse. Other builders used electronic speed controllers from radio-controlled cars. This provided the ability to be able to vary the speed of motors but lacked current capacity. Now most combat robots use Electronic Speed Controllers made specifically for the rigors of combat robotics, however some builders still use “servo switching” to control motors that need only be turned off and on. Electronic speed controllers for combat robots use a method of speed control called Pulse Width Modulation. Instead of varying the voltage to control the speed of the motor, short pulses of electricity are sent to the motor to control how fast it runs. Switching the power off and on thousands of times per second allows for smooth precise control of the robot and has given robot builders Electronic Speed Controllers that can handle the high current needed to build powerful combat robots.