| 摘要 |
PROBLEM TO BE SOLVED: To provide an encoder capable of informing of the existence of an abnormality of the encoder even when a detection object is in a low-speed state or in the stop state. SOLUTION: When the change with time of two-phase signals A, B is detected by a change detection means (an XOR gate XO1, D type flip-flops 111, 112, and an NAND gate NA1), counting is started by a counter 113. When ripple carry RC is outputted from the counter 113, or when an external reset signal #SRES is validated, an internal reset signal #RES is validated. At that time, a pulse synthesis part 103 generates a signal equivalent to the movement of one cycle portion of a four-bit counter, selects a two-phase signal performing a pseudo one-cycle movement operation, and defined asϕA,ϕB, and A multiplexer 101 outputs a superimposed signalϕC acquired by time sharing of an origin signal C and magnetic pole position detection signals U, V, W by usingϕA,ϕB as selection signals.
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