| 摘要 |
PURPOSE:To stably operate a frequency converter even at a light load time by supplying a gate pulse to an inverter when the output voltage exceeds the prescribed value and delaying the gate phase of a power rectifier. CONSTITUTION:When an output voltage rises at a light load time, a gate pulse signal is inputted from a comparator 10 to a logic circuit 11. A gate pulse is supplied from the logic circuit 11 to an inverter 1. Since the pulse is commutated at the time, the output currnt is inverted, the power factor is deteriorated and the supply of energy to a tank load circuit 4 is decreased. Further, an analog switch 17 is closed by the signal from the comparator 10, and the signal of a setter 14 is preferentially inputted to a phase controller 15 of a power rectifier 3. In this manner, the gate phase of the rectifier 3 is delayed to control the decrease of the DC voltage. |
