A single chip INTEL 8748 based Pulse Width Modulation system has been developed. Six PWM signals for three phase application are generated on PORT 1 by outputting DATAWORDs after a delay determined by DELAY-WORDs. Two different sets of DATAWORDs are used for forward and reverse motions. The PWM signals have been used to run two ac synchronous motors to control a tracking photovoltaic system. The motion of the tracker is decided by Input signals on BUS PORT and PORT 2 (UPPER). Bit 6 and 7 of PORT 1 and lower nibble of PORT 2 are used as gate signals for tri-state buffers to control two or more motors from one set of PWM signals.
V. Dutta, V. Dutta,
"A Single Chip PWM Generator For Tracking Photovoltaic System", Proc. SPIE 0854, IECON '87: Motor Control and Power Electronics, (19 October 1987); doi: 10.1117/12.942980; https://doi.org/10.1117/12.942980