COMMUTATION SPARK DETECTOR OF DC MACHINE

摘要

PURPOSE:To enable to accurately detect a commutation spark even under an environment of noise of light by generating a signal synchronized with the period of slots of a rotor, and synchronously detecting the output of photoelectric converting means by the signal. CONSTITUTION:A sinusoidal wave r(t) synchronized with the period of slots is formed in a slot period synchronizing signal generator 7. The generator 7 has an electromagnetic coupler 9 for outputting a pulselike signal having the period of the slots, a waveform shaper 10 for converting it to a rectangular wave, and a phase locked loop circuit 11. The signals r(t) and a photoelectric multiplier output S(t) are inputted to a synchronous detector 12, processed by multipliers 13, 15 and an integrator 14, smoothed by low pass filters 16, 17, individually and outputted. The outputs of th detector 12 are squared and added by multipliers 18, 19 and an adder 20 to obtain detected output O(t) proportional to the square of the amplitude of the component of the slot frequency.