| 摘要 |
PURPOSE:To prevent surely the simultaneous turning-on of transistors (TRs) of a power drive stage caused due to a delay time by providing a switching means short-circuiting the base-emitter of the TRs of the power drive stage when the drive pulseis missing. CONSTITUTION:AND gates 13, 14 are provided, which are controlled based on the result of polarity discrimination of the drive signal with respect to the signal reference level, the output of a pulse signal for reverse drive is inhibited by a AND gate 14 in response to the Q output of a D-FF12 thereby preventing a TR Q12 from being turned on simultaneously with a TR Q11. Further, TRs Q15, Q18 provided to decrease the delay time tOFF to power TRs Q12, W10 are turned on momentarily in response to the missing drive pulse of the power TRs Q12, Q10 and the delay time is reduced by short-circuiting the base-emitter of the TRs Q12, Q10. |
