over voltage and low voltage protection circuit

[wiparat]

**broken link removed**

This is an electrical circuit protection device sound disappeared, when too much voltage 220V, and protection, when pressure is too low with Using the relay cut off power when voltage problems..............

 

[audioguru]

The schematic is a fuzzy Jpg file type instead of a very clear PNG file type.
The schematic is too small to see anything on it.

Save and attach a larger schematic as a very clear PNG file type.

 

[ronsimpson]

1)Can't read your schematic.
2)You need Hysteresis! If you do not have Hysteresis the relay will chatter! Example; If the line voltage is 0.1 volt above the turn off point then the load will turn on but with the load on the line sags 0.1 volts and the load will turn off. (oscillation)
3)You have a pair of resistor/ Zener diodes. The resistor should get its power from the 12V not from the unregulated source. Also why not use only one R/D? Why not use two resistors? (6 volts)
4) What is across the relay coil. Diode pointing up = good. Other device = ? Remove Zener.
5)What IC? LM339 Wire the two outputs together with out resistors. Add pull up resistor.

 

[Grossel]

I will add this thread on my example list over how a schematic should NOT look like.