| 摘要 |
PURPOSE:To improve the response performance of a base driving circuit of a power transistor(TR) by connecting a 2nd photodetector interrupting rapidly the secondary side circuit in series with a 1st photodetector. CONSTITUTION:The 1st photodetector PTr1 as a switching element is provided to the secondary side circuit B driving directly the base of the power TR PT. The 2nd photodetector PTr2 interrupting rapidly the circuit B is connected in series with the 1st photodetector PTr1. The 1st and 2nd photodetectors PTr1, PTr2 constitute 1st and 2nd photocouplers 21, 22 together with 1st and 2nd light emitting elements LED1, LED2. A primary side circuit A outputs a power TR turn-on signal to a 1st light emitting element LED1 and outputs a power TR turn-off signal descending synchronously with the fall of the power TR turn-on signal to a 2nd light emitting element LED2. |
