Trick to Protect Home Appliances

Here is a low cost Spike protector for Electric appliances, TV, Computer etc from high voltage spikes that appear in the power lines. Very high voltage spikes and transients develop momentarily in the supply lines when lighting occurs. Such short duration high voltage spikes also super impose on the mains when high current loads are switched on or when power resumes after a power failure due to high magnetic field in the distribution transformer. Even though the spikes are short living, they can cause permanent damage in appliances. This MOV based circuit can be added in the existing switch board to protect the appliances from high voltage spikes. If heavy transients develop in the mains, the MOV in the circuit short circuit the lines and the fuse will blow out.

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9 responses to “Trick to Protect Home Appliances

  1. Sir,
    Please give circuit to protect TV from the spikes through Cable TV wires.
    Thank you in advance.

  2. Sir thanks for this excellent article…
    I have a MOV ! But i am confused whether I can use this or select some another one…
    On my MOV : PVR7D471K is written…

    Can I use this or not sir…
    And what is the meaning of that code….

  3. Dear Sri.DMK,
    you have not mentioned about the varieties of MOVs available and their places of usage. How much should be the minimum load and the maximum load to be used with this circuit, and also, please give us the details of their availability and approx. rate.
    V. Hari Hara Prasad

    • Hello Sri.VHHP
      MOVs are used in Spike guarded extension cord( one used with computer) SMPS. Telephone junction box, TV etc.Different types of MOVs are available which are rated depending on the surge voltage. 130 VAC, 250 VAC, 275 VAC, 300 VAC etc.The selection is based on the voltage level at which the breakdown occurs. For example, if the AC voltage is 230, then 275 VAC type is an ideal choice. 130 VAC is for 110 volts AC. Load rating is not a parameter, but the input AC voltage.In 275 VAC type, breakdown occurs if the line voltage increases( due to spike) above 275 volts. MOV cost only Rs.5 and available in all electronic shops.