Abstract: A motor controller system (15a) for dc power source motors (10) which includes a sensor device (16) that operates to measure and generate a voltage signal from the motor current and the rate of change of said current, and a programmable input/output processor (12) which receives voltage signals as input from the motor current, dc power source (11) and/or motor (10) and compares on or more of these voltage signals to one or more control parameters. Based upon these comparisons, the processor (12) generates a pulse width modulation control signal, which triggers a switching mechanism (14) and related interrupt service routing to make adjustments to the operational parameters of the motor by periodic interruption of the motor current.