| 摘要 |
PURPOSE:To answer without delay by a regular current waveform without answering by a spike current component of an input current waveform, by comparing the reference voltage on which differential voltage of detection voltage has been superposed, with the detection voltage. CONSTITUTION:A detection current transformed by a transformer T1 is shunted by resistnaces R1, R2, and a voltage waveform almost similar to a current waveform is generated across the resistance R2. This voltage waveform is applied to not only one input termianl of a comparator CP but also a differentiating circuit constituted of a capacitor C3 and a resistance R3, and to the reference side input terminal of the comparator CP, superposed reference voltage obtained by superposing the differential voltage on the reference voltage is applied. In this way, even if input voltage has been raised by a spike current component of the input current waveform, input voltage of the reference side is also raised in accordance with said rise, and the comparator is capable of exactly detecting an overcurrent without answering by the spike current component. |
