Automatic power factor detection device in meter

摘要

The present invention relates to a meter for detecting a power factor to the input voltage, the voltage of the input power source 1 is applied to the microcomputer 5 through the transformer 3 and the rectifying diode (D1), the load ( The voltage due to the current delayed by a time corresponding to the power factor cosφ by 9) is applied to the microcomputer 5 through the current transformer 7 and the rectifying diode D3. The microcomputer 5 detects the input time difference between the two voltages as the timer 51, reads the power factor cosφ corresponding to the input time difference from the internal storage 52, and applies it to the display unit 8 and the transmission unit 11. .;In this way, the present invention can easily know the power factor for the input power, there is an effect that no separate calculation is required to detect the power factor.