| 摘要 |
PURPOSE:To enable the certain operation of a wiper from the time of switching-ON of a power source with a relatively simple constitution by constituting a pulse oscillator in which a differential amplifier is used as hysteresis comparator and in which one condenser and two resistors are added. CONSTITUTION:When a wiper switch WS is turned-ON, a bias voltage is applied to a transistor Q2, which is turned-ON, and also Q3 is turned-ON, and a movable contact SO is closed to the contact Si side through the excitation of the coil M of a relay RL. Accordingly, the wiper operating motor connected with terminals T2 and T3 is started concurrently with the turning ON of the switch WS. At this time, a condenser C1 is charged through R1 and D1 by turning-On of Q3, and if the charged voltage exceeds the cut-off level of Q1 or the base voltage of Q2, then Q1 is turned- On and Q2 is turned-OFF, and the motor described above is brought to stop. After that, when C1 is discharged and prescribed voltage is reached, the motor is started again in the same way. |
