| 摘要 |
PURPOSE:To obtain an elevator system of high reliability by detecting the pulse to be generated next with one pulse out of three sets of the pulses generated from an AC speed generator as a reference thereby detecting the rotating direction of the AC generator. CONSTITUTION:Three pulses phi1-phi3 per cycle are generated synchronously with the interwire voltage of the output of a speed generator ACPG revolving synchronously with an electric motor driving a moving body for an elevator, etc. The outputs of Q1 of an FF1 and Q2 of an FF2 are made L level by the pulse phi1 which is used as a reference out of these pulses, and the outputs of the FF1, FF2 are inverted by the pulse generated after phi1, whereby the phase sequence of the pulses phi1- phi3 is judged MPU. |
