Project Description
Name:
Over and Under Voltage cut-off With Delay.
Function:
This circuit is used before power supply of sensetive equipments to protect from
over voltage, under voltage and to some extent transient surge protection.
Description:
The circuit contains 4 transistors for over and under-voltage detection, 1 transistor for
relay driving, delay is acheived through R-C coupling.
It contains 4 presets for over-voltage setting, under-voltage setting, under voltage cuttoff
delay and over voltage cuttoff delay.
The circuit idea is taken from EFY and was built in around year 2002.
The PCB is custom designed in home as per the cabinet space using conventional stressing paper,
Copper laminated board and FeCl3 etchant.
It is not directly connected to AC Mains but through a 12V transformer, so calibration is required.
It was built for protection of pin-pad based access control system.
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