| 摘要 |
PURPOSE:To prevent a secondary failure from occurring when a large power transistor and a power diode fail by providing an overcurrent detecting resistor at the secondary side of a current transformer and applying the output to an overcurrent detecting and conduction breaking circuit. CONSTITUTION:Overcurrent detecting resistors R1, R2 are respectively inserted into the secondary side of a current transformer CT. A voltage which is produced by a current flowed through the resistors R1, R2 is introduced to a controller C/C through connecting lines 105, 106 which respectively include diodes. The overcurrent detecting and conduction breaking circuit EDT in the controller C/C detects threshold voltage when the voltage produced at the resistors R1, R2 exceeds the specific threshold voltage, and immediately interrupts the supply of the conduction control signal to transistors Q3, Q4 thereafter. |
