High-low voltage cut-off Rev. 1.0

Objective:

                In order to protect electrical devices prone to damage due to Higher or lower input Voltage, this simple design is to Drive Switches on input Voltages. If input voltage level is higher or lower than set values, the switches will open and cut the supply.

Operation procedures:

                There are 2 comparator circuits on the input (or a representation of input voltage lever in case of High Voltages, AC mains for example) that compare the voltage level of input with our desired set points. In case one of the two undesired conditions mentioned above happened to input, the switch(es) which were normally close become open, until the input situation is resolved. Also, a delay circuit can be placed to make sure that the right input level of voltage is settled.

Input specifications:

In this design ,in put voltage is AC mains, so the power needed for the whole circuit is supplied with the input signal it self.

Output specification:

• 220VAC , 4/6/8A based on the output relay specification.