How To Make Digital Over Under Voltage Protection System?

Step1

A digital over under voltage protection system is a device that can be used to protect our devices from being damaged by too high or too low voltage. Sometimes in electrical systems overvoltage happens this can be permanent, a spike, or a transient all these can damage devices if this overvoltage remains for a certain time. over under voltage protection system can be set for a specific high voltage and low voltage limit for a specific time, if voltage goes above the overvoltage limit and stay above for a set time the system cut off the supply, if voltage goes below the under-voltage limit and stay above for a set time the system cut off the supply. The system we have designed is programmable we can set the overvoltage limit, under-voltage limit, and the delay time the over-under voltage limit can be set from 60VAC to 300VAC turns on and off without delay. The system has two relays one turns on and off without delay and the second turns on and off after a delay this delay time can be set from 0 to 99 sec.

Step2

ATMega328 microcontroller is the brain of this circuit it is the main component of the system it reads the voltage from the voltage sensor and performs two tasks, the first one is to display the supply voltage on the LCD a 16×2 alphanumeric LCD is used for displaying supply voltage, relays on-off status, over-voltage limit, under-voltage limit, and delay time. The system has two 12V relays to cut off the supply first relay activated or deactivated immediately when over voltage or under voltage occurs and the second relay activated or deactivated after a set delay time. The microcontroller cannot supply enough power to drive the relays so a relay driver is used to drive the relays. The relay driver is made of a BC547 transistor. The system runs on 12V supply the microcontroller and LCD need 5V supply for that a buck regulator is used to convert 12V supply to 5V supply MC34063 IC is used to make the buck regulator. Three pushbuttons are used to set the overvoltage limit, under-voltage limit, and delay time. One of the buttons is the menu button and rest two buttons are up and down buttons.

Step3

let’s set the over voltage limit, under voltage limit, and delay time.

first press the menu button for a few seconds

then press the up and down button to set the over voltage limit

then press the menu button again to set under voltage limit

now you can set under voltage by pressing up and down button

press the menu button again to set the delay time

you can now set under voltage by pressing the up and down button press the menu button once again to save all the values.

Step4

Circuit Diagram:



Components:
1x 16X2 LCD https://s.click.aliexpress.com/e/_dTN…
1x ATMEGA328 IC https://s.click.aliexpress.com/e/_d6c…
1x MC34063 IC https://s.click.aliexpress.com/e/_dX4…
2x PC817 Optocoupler https://s.click.aliexpress.com/e/_dVW…
1x BD139 Transistors https://s.click.aliexpress.com/e/_dWA…
2x BC547 Transistors https://s.click.aliexpress.com/e/_dXe…
4x 1N4007 Diodes https://s.click.aliexpress.com/e/_dT5…
4x 1N4148 Diodes https://s.click.aliexpress.com/e/_d6K…
1x 1N5819 Diode https://s.click.aliexpress.com/e/_dT5…
2x RED Led https://s.click.aliexpress.com/e/_dSK…
1x 16MHz Crystal https://s.click.aliexpress.com/e/_dZI…
3x Push Buttons https://s.click.aliexpress.com/e/_dVr…
1x 1mH Inductor https://s.click.aliexpress.com/e/_d6s…
2x 33p Capacitors https://s.click.aliexpress.com/e/_dZM…
1x 1nF Capacitor https://s.click.aliexpress.com/e/_dZM…
1x 1uF Capacitor https://s.click.aliexpress.com/e/_dT3…
1x 100uF Capacitor https://s.click.aliexpress.com/e/_dU0…
1x 470uF Capacitor https://s.click.aliexpress.com/e/_dU0…
2x 10k Trim pots https://s.click.aliexpress.com/e/_Bf6…
18x 10k Resistors https://s.click.aliexpress.com/e/_dW4…
6x 1k Resistors https://s.click.aliexpress.com/e/_dW4…
1x 1R Resistors https://s.click.aliexpress.com/e/_dW4…
1x 3k3 Resistors https://s.click.aliexpress.com/e/_dW4…
1x 680R Resistor https://s.click.aliexpress.com/e/_dW4…
1x 4k7 Resistors https://s.click.aliexpress.com/e/_dW4…
2x 12V Relay https://s.click.aliexpress.com/e/_d6z…
1x 12V Transformer https://s.click.aliexpress.com/e/_A85AVx
7x 2 Pin Terminal Blocks https://s.click.aliexpress.com/e/_dYS…
2x 3 Pin Terminal Blocks https://s.click.aliexpress.com/e/_dTU…
Male Header https://s.click.aliexpress.com/e/_Bfi…
jumper Wires https://s.click.aliexpress.com/e/_dVh…

6 thoughts on “How To Make Digital Over Under Voltage Protection System?”

  1. Very nice sir thank you so much
    Can u pls add current sensor around 30A for reading the load current and on/off the relay as per setted parameters like under current & over current I hope you understand what I m saying this will very helpful to make an ideal controller pls make it ASAP

    Reply

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