| 摘要 |
PURPOSE:To prevent the overcurrent damage of a switching element by stopping the supply of a voltage when the level of the current flowing through a series circuit of a DC motor and the switching element becomes higher than the prescibed value. CONSTITUTION:Transistors Q2-Q5 for driving a motor M are controlled by transistors Q1, Q6 which switches On or OFF in accordance with signals supplied to input terminals IN1, IN2. A resistor R9 for detecting a current is connected to the series circuit of the motor M and the transistors Q2-Q5. When an overcurrent flows through the motor M, a voltage across the resistor R9 rises, causing an SCR1 to be conducted ON. Accordingly, the transistor Q7 of a voltage supply circuit 2 is interrupted, thereby stopping the supply of a voltage. In this manner, the overcurrent damage of the transistors can be prevented. |
