SYSTEM FOR CONTROLLING THE SPEED OF AN ELECTRIC MOTOR

摘要

The system comprises two counters (1 and 2) which receive counting pulses from an oscillator (5) and control pulses from a tachogenerator (11). The first counter (1) is reset by a tacho-pulse and counts to a predetermined maximum value. The counting direction of the second counter (2) is reversed both when a tacho-pulse appears and when the predetermined fixed value is reached by the first counter (1). The control signal for the motor is obtained by comparing the count of the second counter (2) with a reference value (R) in a comparator (14) to derive an on-off signal.