| 摘要 |
PURPOSE: A device for detecting open-phase and reversed phase signals is provided to reduce errors by simply designing the device, and shorten the detection time when the device detects the open-phase and reversed phase signals. CONSTITUTION: The first through the third diodes(D1 to D3) rectify alternating current(AC) outputted from a transformer(CT) of R,S,T phases into direct current(DC), respectively. The first through the third load resistors(R1 to R3) convert the direct current rectified in the first through the third diodes(D1 to D3) into voltage signal, respectively. The first through the logical elements(U1 to U3) output 0 or 1 logical value according to the voltage of the first through the third load resistors(R1 to R3), respectively. The fourth through the sixth logical elements(11 to 13) output the first and second logical values according to the logical values outputted from the first through the logical elements(U1 to U3). The seventh logical element(14) outputs reversed phases of R,S,T according to the first logical value of the fourth through the sixth logical elements(11 to 13). The eighth logical element(15) outputs the third logical value according to the second logical value of the fourth through the sixth logical elements(11 to 13). The ninth logical element(16) outputs open-phases of R,S,T according to an output signal of the eighth logical element(15).
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