| 摘要 |
The time control is synchronised with the mains frequency, and the clock electronic circuits are driven from a source other than the mains, and from which energy is taken for adjustment of the tariff stage. Connection between the mains and the clock function controlling circuits is such that in the event of a break in mains supply, an oscillator circuit is connected which simulates the mains frequency. This circuit controls the clock function for the duration of the break, and the mains frequency condition is probed by a sensor which controls the function of an alternative circuit, to the one input of which the mains frequency is connected, and its other input is connected to the oscillator circuit. |
