| 摘要 |
PURPOSE:To detect abnormality of an output transistor of a controlling circuit during normal operation by inputting a check pulse of constant period, and comparing the inversion signal of output pulse and the check pulse in pulse width. CONSTITUTION:Check pulse is supplied at constant period from a check pulse oscillating circuit 10 to an output transistor of the controlling circuit 1 through an exclusive OR circuit 3. The output of an exclusive OR circuit 5 to which the on/off signal of a collector and a signal made by delaying the check pulse by a delaying circuit 4 is inputted to a T-flip-flop circuit 6, and an inversion signal is obtained during rise to fall of the on/off signal of the collector. When this inversion signal and the check pulse are inputted to an NAND circuit 7, the NAND circuit 7 outputs an abnormality detection signal consisting of low value signals if the output transistor is out of order. |
