| 摘要 |
PURPOSE:To enable the obtaining of an operation voltage proper with respect to a quantity of electricity measuring circuit whichever one phase of a power source input is omitted. CONSTITUTION:A first rectifier 4 which rectifies an output of a first power source transformer 2 is connected to an AC side terminal of a second rectifier 5 which rectifies an output of the second power source transformer 3 and both the power source transformers 2 and 3 are connected in series on the secondary sides thereof through a connection point thereof. With such an arrangement, When a phase is omitted, voltages combined in the same phase, namely, a rectified value of the power the same as the normal power is applied to a constant voltage circuit 6. Whichever one phase of a three phase input is omitted, a rectification voltage equivalent to a line voltage can be extracted from a power source circuit thereby enabling the obtaining of an operation voltage of a proper quantity of electricity measuring circuit 7. |
