Published:2011/7/9 2:07:00 Author:Fiona | Keyword: undervoltage,overvoltage protection, alarm | From:SeekIC
Work principle
Circuit is shown as above.Mains voltage reduces voltage by C3,maintains voltage by DW,VD6,VD7,C2 rectifier filter output maintaining DC voltage supply circuit.Another path is rectified by VD1,reduced voltage by R1 and filtered by C1, the voltage about 12V produced in RP1、RP2 detects the input signal of the mains voltage change.Door IC1A,IC1B form the overvoltage detection circuit, IC1C is undervoltage detection,IC1D is switch,IC1E,IC1F,piezoelectric ceramicchip YD and other components form the audio pulse oscillator. Transistor VT,relay J and other components form the protection movement circuit.Red LED1 is for mains overvoltage indication,the green LED2 is for mains voltage undervoltage indication.
Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Control_Circuit/Undervoltageovervoltage_protection_alarm_circuit.html
Print this Page | Comments | Reading(3)
Code: