Surge Protector




About: I make diy and electronics based projects.

This is a surge protector

Step 1: Surge Protector

Hi, today i will show how to make a surge protector.It will protect your electronics items in surge or spike.Surge and spike means over voltage,over current and high frequency.It will protect from eddycurrent.High voltage in high frequency is known as eddycurrent.

Step 2:

When the input power ON the green led turn On.When we press the push on switch the output power will on.The red led indicate output power on.

Step 3:

I added a 1 ampere fuse and fuse carrier you can use 2a or 3a fuse for higher load

Step 4:

The output voltage is stable

Step 5:

I added a led indicator for showing fuse blown.If we shorted the output the fuse surely blow.

Step 6:

Take a look at the inside.?

Step 7:

This is the circuit diagram

Step 8:


1)12v relay five pin

2)12-0-12 500ma transformer

3)In4007 diode

4)1000uf/25v capacitor

5)Bt 169 scr

6)1k resistor (2)

7)470 ohms resistor

8)2.2k resistor

9)green (1) red (2) led

10)Mov 250v

11)push on switch

12) 3a fuse and fuse carrier

13)3pin socket

14)3pin code wire

15)plastic container

Step 9:

Thanks i hope you like this.?

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    12 Discussions


    2 months ago on Step 7

    A word of caution: this design is not great - it's slow to act (depending on a relay) it will take many ms to switch off (at current < max relay current) and a 250V mov (in 120V installation) won't help much either.
    In other words if you want to secure an expensive piece of kit you are better off with something else.
    Looking at the pictures - naked mov terminals (at mains level) passing just right next to a screw that sticks out on the front panel - potential death trap.

    Finny philip

    Question 2 months ago

    One more qstn,
    Can i use a 16 amp plug socket and a 16 amp fuse in this circuit?

    1 answer
    Electro makerFinny philip

    Answer 2 months ago

    You can use 16 amp plug socket but you can't use 16 amp fuse. I recommend using 1 amp fuse because it can handle upto 500w.

    Finny philip

    3 months ago

    At high voltage Will the circuit breaks completely or the voltage gets regulated?
    And also after what voltage it acts?

    1 reply
    Finny philip

    Question 3 months ago on Step 8

    What is the use of transformer?
    Can i use without a transformer?
    How well a mov work? I heard that mov cant withstand high voltage or current.
    Can i use it for higher loads like upto 6amp or 8

    2 answers
    Electro makerFinny philip

    Answer 3 months ago

    Transformer is must in this circuit you can use a power supply instead of transformer. Mov is used for over voltage protection


    Question 3 months ago on Step 8

    Very Interesting, keep inspire!!

    I would like to ask you what component is actually the one goes to the realy, and the other goes to the AC plug. (Triangle on top and triangle at the bottom of the drawing).

    Thank you very much!

    1 answer
    Electro makerAndria6000

    Answer 3 months ago

    I don't understand which component you are asking,in input there is a 1amp fuse and in Output there is a mov

    Bro i participate in a exihibition of science and technology i got 1st price in that exihibition.I make this surge protector for that exibition. Iam using this surge protector. Thanks have a nice day.