Phase-locked loop automatic matching selection circuit for power meter

Abstract

The invention relates to a phase-locked loop automatic matching selection circuit for a power meter. The phase-locked loop automatic matching selection circuit comprises a power supply, an external voltage, a current input signal, a channel selection circuit, an input signal frequency conditioning circuit, a phase-locked loop frequency multiplier circuit, an input signal detection circuit and a phase-locked loop matching selection circuit. External voltage and current input signals are connected with the input end of the channel selection circuit; the output end of the channel selection circuit is connected with the input end of the input signal frequency conditioning circuit; the output end of the input signal frequency conditioning circuit is connected with the input ends of the phase-locked loop frequency multiplier circuit and the input signal detection circuit; the output end of the input signal detection circuit is connected with the input end of the phase-locked loop matching selection circuit; the output end of the phase-locked loop matching selection circuit is connected with the control end of the phase-locked loop frequency multiplier circuit part; and the output of thephase-locked loop frequency multiplier circuit part is used as a trigger signal for ADC sampling. Software programming participation is not needed, automatic matching selection of the phase-locked loop is realized in a hardware mode, the defects of small locking bandwidth range, low stability and the like of a traditional single phase-locked loop circuit are overcome, and the measurement efficiency and accuracy of the digital power meter are improved.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to a phase-locked loop automatic matching selection circuit for a power meter. Background technique [0002] With the rapid development of the modern power electronics industry, there are more and more power supply and load products. Most power electronic systems are inseparable from power supply and load. Due to the conversion efficiency of power supply, load power consumption and other related issues directly affect related products. The performance of these systems requires special measuring instruments to detect the energy consumption of these systems. Therefore, there is an increased demand for home appliance manufacturers to use digital power meters to test power supply products and home appliances; the speed requirements for digital power meters to detect products also further improved. [0003] The digital power meter needs to sample the instantaneous value of t...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is to provide a phase-locked loop automatic matching selection circuit for power meters, which solves the defects of the traditional single phase-locked loop circuit, such as small locking frequency range and low stability, and improves the performance to a certain extent. Efficiency and Accuracy of Digital Power Meter Measurement

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