Three-phase alternating current phase sequence testing circuit

Abstract

The invention discloses a three-phase alternating current phase sequence testing circuit. The three-phase alternating current phase sequence testing circuit comprises a waveform and amplitude shaping circuit capable of shaping the waveform of inputted alternating current, and a phase sequence testing circuit capable of carrying out the logic control on the time sequence. A three-phase switch impulse signal from a waveform transformation circuit transistor is respectively connected with two paralleled CLK terminals and reset terminals of a D-shaped positive edge trigger between the A, B, C three-phase waveform and amplitude shaping circuit and the phase sequence control circuit; and high levels or low levels outputted according to a time sequence cycle period are sent to a phase sequence judgment transistor of the phase sequence output control circuit. The three-phase alternating current phase sequence testing circuit can dynamically test the three-phase existence only through the paralleled D-shaped positive edge trigger outputting the switching impulse signal and the phase sequence judgment transistor, thereby preventing the harm to a tester or a product caused by an error phase sequence, and consequently solving the problems of phase sequence errors and phase deficiency when detecting a three-phase power supply.

Description

technical field [0001] The invention relates to an electronic test device for detecting phase sequence circuits of three-phase alternating current. Background technique [0002] In the past, before adding a three-phase power supply to the product, the method of detecting the phase sequence and phase loss state of the three-phase sine wave voltage usually used image 3 The simple phase sequence indicator shown is used to detect its phase sequence. It uses a phase sequence detection relay in the circuit, and connects the three phases to the input terminal of the phase sequence detection relay. The output is normally open and normally closed contacts. , Connect the contacts to the circuit to realize phase-loss and power-off. When in use, just connect the three wires X, Y, and Z to the three-phase circuit, and judge the phase sequence of the three-phase alternating current by turning off and on the neon tube in the fluorescent lamp starter. If the neon tube is on, X, Y, and Z a...

AI Technical Summary

Problems solved by technology

The disadvantage of the device for protecting the power supply is that the circuit is complicated and the cost is high

If the phase sequence is wrong or when the phase is missing, it will cause damage to the product when the product is added

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