| 摘要 |
PURPOSE:To prevent the amplitude and phase of an inverter output voltage from varying by detecting a voltage between the collector and the emitter of a transistor, controlling the base drive in response to the voltage, thereby eliminating an ON delay timer. CONSTITUTION:The output of a PWM generator 1 is applied through an inverter 6 and AND circuits 29, 30 to base drivers 4, 5 to drive transistors TR1, TR2 which form upper and lower arms of an inverter. Voltages between the collectors and the emitters of the transistors TR1, TR2 are respectively detected by voltage detectors 11, 12, the outputs are applied through comparators 21-24 and OR circuits 25-28 to AND circuits 29, 30 to control the base drives of the transistors TR1, TR2. |
