Digital Motor Driver For R/C Models

EE 56 December 1987 DIGITAL MOTOR DRIVER FOR R/C MODELS R/C modellers will delight in building and using this ultra-compact, high efficiency, all-digital power driver for electric motors with a current requirement of up to 40 A. The circuit described here is based on pulse-width modulat- ion of power FETs at a fre- quency of 1 to 2 kHz. The motor driver can be tailored to in- dividual needs, which means that the number of FETs fitted in parallel in the power output stage depends on the current requirement of the motor used. Flyback diodes are included to ensure a smoothly running motor at all speeds. Two presets not only enable ad- justing the zero point and the maximum speed in accordance with the R/C system used, but in addition select operation of the motor in the single or dual quadrant mode. Single quad- rant operation is particularly useful for non-reversing motors in model aircraft. The proposed controller makes it possible to stop the motor when the control lever is pulled...