| 摘要 |
PURPOSE:To obtain a single-phase ac constant voltage power source monitoring device which can speedily detect the stop of a single-phase ac constant voltage power source or the voltage lowering, free from leak. CONSTITUTION:A single-phase ac constant voltage power source monitoring device is equipped with a zero cross point detecting means 2 for a single phase ac constant voltage power source 1, phase judging means 3 which judges the phase of the single-phase ac constant voltage power source 1, having the zero cross point as starting point, instantaneous voltage judging means 4 which compares the absolute value of the instantaneous voltage of the single-phase ac constant voltage power source 1 with a standard voltage and obtains the result and a power source state judging means 5 which judges the state of the single-phase ac constant voltage power source 1 from the information of the generation of the zero cross paint at a prescribed phase position judged by the phase judging means 3 and the instantaneous voltage obtained by the instantaneous voltage judging means 4. Accordingly, the stop of the single-phase ac constant voltage power source and the voltage lowering can be detected instantly free from leak. |
