| 摘要 |
PURPOSE:To reduce a whole circuit by detecting an overcurrent without using a current transformer or a current shunt. CONSTITUTION:A switching element 1 for supplying a current to a load is controlled by a driver 2. When an overcurrent flows to the element 1, a high side voltage of the element 1 is abnormally raised. This voltage is applied to a voltage detector 3, and a voltage is generated across a resistor 7 by the current. This voltage is compared by a voltage comparator 4 with the voltage of a reference voltage source 5. If it exceeds it, the comparator 4 feeds a signal to a driver controller 6 to turn it ON, thereby reducing the high side voltage of a resistor 13 to turn OFF a driving transistor 12. Thus, the driving signal of the switching element is interrupted. |
