Digital 3=phase pulse duration modulation signal generator for motor controller - uses comparison of reversible counter count values with stored reference values for each motor phase

摘要

The signal generator has a clock circuit (112) providing indexing pulses for a reversible counter (1), with a comparator (6) providing a coincidence signal (6A) when the count value is zero. A register (2) holds a max peak value for the counter count value, compared with the actual peak value of the count, to provide a second coincidence signal (7A) to reverse the counting direction, with a further reversal in response to the first coincidence signal (6A). Respective registers (3, 4, 5) hold the threshold values for generating the modulated signal for each of 3 different phases of a 3-phase motor, with further registers (8, 9, 10) storing these values upon the successive coincidence signals being supplied. Digital comparators (11, 12, 13) compare the count values with the values in the latter registers (8, 9, 10) for generating the output signals (28, 29, 30). USE - For digital 3-phase motor controller.