Principle and wiring of old watt-hour meter

(1) Basic Principles of Mechanical Watt-hour Meter

Traditional watt-hour meter refers to inductive mechanical watt-hour meter (induction meter or mechanical meter for short), which is mainly composed of voltage coil, current coil, aluminum disk, permanent magnet, counter and other devices by using electromagnetic induction principle. Its working principle is as follows: according to the electromagnetic induction principle, when the electric meter is electrified, electromagnetic fields are generated in the current coil and the voltage coil, forming a rotating moment on the aluminum plate, and the counter is driven to count through the transmission gear. The greater the current and voltage, the greater the torque, the faster the counting and the more electricity consumption. The rotating torque of aluminum plate is proportional to the active power of load. Meter constant refers to the measured value of unit electric energy value (degree or kilowatt? Hour) corresponds to the number of revolutions of aluminum plate, and the unit is revolutions per kilowatt? hour

(2) Basic Principles of Electronic Watt-hour Meter

Electronic watt-hour meter uses electronic circuit/chip to measure electric energy; The voltage signal is converted into a small signal for electronic measurement by a voltage divider or a voltage transformer, and the current signal is converted into a small signal for electronic measurement by a shunt or a current transformer; the converted voltage and current signal are multiplied by analog or digital through a special electric energy measuring chip to accumulate electric energy, and then a pulse signal with a frequency proportional to the electric energy is output; The pulse signal drives the stepping motor to drive the mechanical counter to display, or it is sent to the microcomputer for digital display after processing.

The wiring is 1.3 in and 2.4 out.