| 摘要 |
PROBLEM TO BE SOLVED: To form a device compactly and inexpensively with the no need for maintenance, without the use of an uninterruptible power supply device for a low-voltage DC control power supply of a conversion part for converting a high-voltage DC power supply of a solar cell power supply or the like into an AC power supply. SOLUTION: A first DC/DC converter 15 for stepping down a DC power supply at the DC input side of a conversion part 6 and for outputting a high-voltage, a primary stepdown power supply from the control power supply of the conversion part 6, and a second DC/DC converter 17 for forming a control power supply by stepping down the primary step-down power supply, are provided at a control power supply part 14. Then, the converter 15 is formed by a semiconductor switch element that is self-biased through the partial voltage of the DC power supply and interrupts the DC power supply, a rectification smoothing means for forming the primary step-down power supply by rectifying and smoothing the interrup output of the element, and a control means that is operated due to the supply of the output of the converter 17 and turns on/off the bias of the semiconductor switch element, so that the primary step-down power supply is a set voltage within the input voltage range of the converter 17. |
