| 摘要 |
PURPOSE:To prevent a transistor from damaging with a simple circuit by opening a power source for a base drive circuit when a stable power source does not maintain the correct value. CONSTITUTION:A power source 13 energizes a controller 11 and a base drive circuit 12. The controller 11 controls the drive circuit 12. Nonstable high voltage EX from a nonstable high voltage power source EN and nonstable low voltage EY from a nonstable low voltage power source EL are inputted to input terminals T1, T2 of the power source 13. A constant-voltage diode 17 for the high stabilized voltage, a constant-voltage diode 18 for the low stabilized voltage, and the base and emitter of a transistor 19 for the base drive circuit 12 are connected in series, and the current limiting voltage EB for the base drive circuit is not outputted unless the high and low output voltages become stabilized output voltages. |
