| 摘要 |
PURPOSE:To realize two or more functions by simple constitution by providing a rush current preventing circuit for short-circuiting a rush current limiting element after a power supply is closed, reference voltages circuit for outputting a detection signal and a switch circuit for stopping or suppressing oscillation of an inverter circuit. CONSTITUTION:Since a rush current is allowed to flow when a power supply is closed, voltage at a point (a) is increased to exceed the reference voltage of a low voltage diode ZD in a reference voltage circuit 53. Accordingly, oscillation is stopped by connecting a transistor(TR)Qb of an inverter circuit 1 to the earth. Thereafter, a current limiting element R2 is short-circuited by turning on a thyrister Q1 because voltage across a current limiting element R4 is increased. The oscillation is started by turning off TRQ2. Next, the oscillation is stopped by connecting a base of the TRQb to the earth when the voltage at the point (a) is increased to exceed the reference voltage of the reference voltage circuit 53 by applying a surge. |
