| 摘要 |
PURPOSE:To make an economical apparatus and improve its reliability by converting a voltage between the middle point of a smoothing circuit capacitor and one phase of an AC power into DC and by connecting said DC output with a control power circuit. CONSTITUTION:In a power source equipment, an AC power 1 is converted into DC by a diode bridge 2, smoothed by capacitors 5A, 5B and supplied to an inverter bridge 6, and further converted into AC to drive a motor. Then, a capacitor 5A, initial charging resistances 3A, 3B and a capacitor 58 are connected in series with a DC side of the diode bridge 2 and said resistances 3A, 3B are short-circuited by a contact 4 after completion of initial charging. Also, a voltage at one end (T phase) on the AC side and at the middle point of the resistances 3A, 3B is rectified by a rectifier bridge 21 and smoothed by a capacitor 22 to be used as a power source for DC/DC converters 8 to 11. Thus, about 1/2 voltage of the AC power 1 can be obtained by a simple circuit.
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