| 摘要 |
PURPOSE:To protect a rush current limiting resistor by detecting whether a current flows to a load power source relay or not by a current transformer, and opening the load. CONSTITUTION:A power source circuit has an AC power source 1, a power switch 2, a rectifier 3, a smoothing capacitor 4, a rush current limiting resistor 5, and a load power source relay 6. A load 8 having a controller for operating the load only when a signal is output from a current transformer 9 is provided to control the relay 6. Thus, if the relay 6 is not closed, the transformer 9 cannot detect a current. Thus, since the load 8 is not operated even if the load 8 is controlled, no load current flows to the resistor 5. Accordingly, the resistor 5 can be protected.
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