| 摘要 |
An electronic type watt-hour-meter is provided to minimize possibility of electrical accident due to outside exposure of an electric apparatus by building a non-contacting relay in a watthour meter. A power supply unit(20) is connected to an input power and supplies input power source to the instrumentation of a watthour meter. A controller(30) controls the instrumentation of the watthour meter. A normal-time/night-time electric power supply measuring unit is connected to the input power and transforms voltage and current of the normal-time electric power and measures the amount of used electric power by computing the voltage and current as an input. A RTC(Real Time Clock,34a) authorizes present time information in the controller. A clock generator(34b) provides an operation clock circle to the RTC. A solid state relay(38) transmits an operating signal in a night-time electric power switch(15) opening and closing the night-time power according to the switching signal of the controller. The watthour meter comprises a photocoupler(37) receiving signals from the controller and authorizing on-off signals in the solid state relay. |
