| 摘要 |
PURPOSE:To improve the reliability by setting the input/output polarity of a gate to produce other edge at the output of the gate when the gate is interrupted, thereby eliminating the damage mode of a switching transistor. CONSTITUTION:An OFF pulse is generated at the rising edge of the output of a NAND circuit IC4, and ON pulse is generated at the falling edge. The output of a NAND circuit IC4 always rises when a power source is OFF and of malfunction, and the OFF pulse is always generated thereby, and an oscillation is then stopped. Thus, the oscillation stop in the state that a switching transistor Q6 is in ON state is eliminated, the damage of the transistor Q6 can be effectively prevented to enhance the reliability. |
