Design on a DC Motor Speed Control

In the paper, we designed and built a high efficiency, low cost DC motor controller use with a motorized golf bag. The controller takes user input to control the speed and drives the motor at that speed regardless of load. The speed control is accomplished in an operational amplifier circuit configured for proportional integral control. This provides quick, smooth motor response to the user input speed and keeps the speed regulated as the motor sees an increased load. A buck converter drives the motor, taking power from a battery built into the cart. The buck converter steps down the battery voltage to provide the necessary motor voltage for the desired speed. The controller also contains a protective element for potentially damaging torque loads. The controller allows the motor to be driven at the maximum current load of 50A for five seconds before shutting the motor down and requiring a user reset.