| 摘要 |
PROBLEM TO BE SOLVED: To provide an input circuit of control equipment which reduces power consumption in the input circuit as a whole, without reducing input current, and which improves the noise-proof chracteristics. SOLUTION: The input circuit is provided with electric power conversion means 3 which are connected to input switches and signal coupling means 4, to which electric power is supplied from the electric power conversion means and by which on/off signals insulated electrically to the on/off signals, based on on/off operation of the input switches, are output to a programmable controller 30. This circuit is electrically controlled so as to feed back to an external DC power supply by the electric power conversion means the difference electric power, in which a second electric power supplied from the electric power conversion means to the signal coupling means is subtracted from a first electric power output from the external DC power supply, when the input switches are turned on. COPYRIGHT: (C)2005,JPO&NCIPI
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