| 摘要 |
PURPOSE:To increase the peak value of current flowing between the emitter and base of a main transistor (TR) and to quicken the time required for turning off the main TR by connecting an inductive element between respective collectors of the main TR and the pre-TR. CONSTITUTION:When a contact 3a of a switch 3 is turned to the 1st fixed contact 3b, the pre-TR 4 is turned on and then the main TR 5 is turned on. When the contact 3a is turned to the 2nd fixed contact 3c, current I1 outputted from a reverse bias power supply 2 and flowing from the collector to the base of the pre-TR 4 through a current feedback diode 6, the 2nd inductive element 9 and a diode 7 and current I2 passing from the emitter to the base of the main TR 5 and flowing from the emitter to the base of the pre-TR 4 through the 1st inductive element 8 are obtained. Since the reverse bias current I2 for turning off the main TR5 can be made to flow more than the absence of the inductive element 9, the time required for turning off the main TR 5 is quickened. |
