| 摘要 |
PURPOSE:To improve safety by stopping forcibly a motor by the signal emitted from a min. voltage setting circuit which checks the voltage of a timer circuit when the voltage of the same powder source supplying a current to the timer means, the motor, etc. drops. CONSTITUTION:The inversion input terminal of a comparator A3 of a timer circuit is connected to the juncture between a resistor R1 and a resistor R2. A voltage V2 which is the reference voltage of a timer circuit is set at said juncture. The voltage V2 is the partial voltage of a constant voltage E2. The inversion input terminal of a comparator A4 of a min. voltage setting circuit is connected to the juncture between the resistor R1 and the resistor R2. When the voltage E2 drops to the voltage or below, at which a timer circuit does not act normally, the output from a comparator A4 of the min. voltage setting circuit is converted from a signal L to a signal H and the signal H is inputted to an OR gate OR1, by which a power transistor Q1 for driving is turned off. The power supply to a motor M is thereby turned off and a transistor Q3 is turned off via an inverter INV2 to turn off a transistor Q2, thereby stopping emergently the motor M. |
