| 摘要 |
PURPOSE:To protect a transistor against an overcurrent by interrupting the transistor by bypassing the base current of the transistor via a thyristor at the time of detecting the overcurrent. CONSTITUTION:Assume that when U and V phases are shortcircuited due to some cause at the time t1 to become overcurrent state, transistors T1, T4, T6 are conducting states, and an overcurrent flows through a battery B the transistors T1 and T4. As a result, the voltage across the terminals of an overcurrent detecting resistor VR2. Thus, the gate voltage of a thyristor TH2 is applied, and the thyristor TH2 is conducted to bypass the base current of the transistor T4. As a result, the transistor T4 is turned OFF to interrupt the shortcircuiting current. |
