Phase sequence detection circuit

Published:2011/4/28 18:50:00 Author:Christina | Keyword: Phase sequence, detection | From:SeekIC

If the motor of the drive pump, compressor or transmission belt reverse run, the equipment will be damaged. This circuit can find out whether the motor phase sequence is error, and protect the motor damaged by the rapid-heating. When the phase sequence is correct, the LED lights. When the phase sequence is not correct, the output power goes low, the LED not lights. The diode and zener convert the sine wave into rectangular logic level pulse. when the phase sequence is correct, G4 outputs a string of rectangular pulse, the pulse width is about 2.5 ns. When the phase sequence is not correct, the output power is zero. The output pulse edge's zero-crossing and B phase's zero-crossing are synchronous, so the output pulse can be used to trig the SCR and drive relay coil which are connected with the Phase B's two ends. This kind of SCR can supply power to relay only when the phase sequence is correct.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Amplifier_Circuit/Phase_sequence_detection_circuit.html

Print this Page | Comments | Reading(3)