Schematics > Security and other sensors and detectors > Power supply failure alarm
Power supply failure alarm
Most of the power supply failure indicator circuits need a separate power
supply for themselves. But the alarm circuit presented here needs no additional
supply source. It employs an electrolytic capacitor to store adequate charge, to
feed power to the alarm circuit which sounds an alarm for a reasonable duration
when the supply fails.
This circuit can be used as an alarm for power supplies in the range of 5V to
15V.
To calibrate the circuit, first connect the power supply (5 to 15V) then vary
the potentiometer VR1 until the buzzer goes from on to off.
Whenever the supply fails, resistor R2 pulls the base of transistor low and
saturates it, turning the buzzer ON.
If there are any problems please contact webmaster@electronic-circuits-diagrams.com
Title: Power supply failure alarm
Source: www.electronic-circuits-diagrams.com
Published on: 2005-02-01
Reads: 324
Print version:  Other schematics from Security and other sensors and detectors
Heating System Thermostat Fire Alarm IR transceiver 1.0 UltraSonic Radar Big Ben Sound Low Voltage Alarm Brakelight Flasher Melody generator for greeting cards Electronics Telephone Talking Circuit Light switch
Schematics > Security and other sensors and detectors > Power supply failure alarm | 
Home
