AC power monitor circuit diagram

Published:2012/10/25 21:12:00 Author:Ecco | Keyword: AC power monitor | From:SeekIC

When AC power is suddenly turned off becauseof lightning strikes and other reasons, the important data stored in computer may disappear, so it needs to add short interruption power detection circuit to protect the memory data. AC220V voltage is rectified and regulated to get +5 V output voltage which is used as the working power of computer, but also working power of timer 74HC123. 74HC123's pin 13 is connected to the microcomputer. When AC power is normal, the 74HC123 timer resets, then output is in high level, computer works properly. When the AC power is anomaly, detection AC power occurs short interruptions with 15ms, then 74HC123's pin 13 output changes from the high to low level, then the computer will do data preservation work.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Power_Supply_Circuit/AC_power_monitor_circuit_diagram.html

Print this Page | Comments | Reading(3)