Single phase power measurement circuit

Measurement of circuit power with a power meter. A power meter (also known as a wattmeter) is an electric instrument. When the switch is turned up, the power is measured;
when the switch is turned down, the power factor is measured . Digital display.
    As shown in the figure is a single-phase circuit power measurement circuit . The power meter W is composed of voltage and current
coils. The current coil is connected in series with the ammeter and then connected to the load Z. The voltage coil is connected in parallel with the load
. The two coils are connected to the positive end of the power supply. end connection.
    After the power is turned on, the power meter displays the load power. When the switch is set to coso, the power factor
of the load can be measured . There are voltmeters and ammeters in the circuit to measure voltage and current at the same time.