Overcurrent protection system e.g. for light-emitting diode (LED) for optical communications

摘要

An energising control works according to a detection signal of the light detector. The control contains an integrator of the detection signal off the light emitter, and determination element if an integration result has attained a preset value, or not. The energising operation of the light emitter is quenched according to the determination element operational results. Pref. the system contains LED energised by a transistor, a photodiode detecting the LED light, a differential circuit for the integration, and a circuit preventing the transistor to energise the LED.