Friday, December 9, 2011

How to Make a Simple AC Mains Surge Protector Device

Spikes or voltage surges can sometimes be a big nuisance as far as the safety of the various electronic appliances are concerned. Let's learn how to make a simple AC Mains surge protector device at home.

More innovative circuits HERE.

A sudden surge or a spike is basically a sharp rise in the voltage lasting not more than a few milliseconds but enough to cause damage to our precious equipment almost instantly.

It thus becomes imperative to stop or block these from entering vulnerable electronic gadgets like our personal computers.

Commercial spike busters are though avalable pretty easily and cheaply too, cannot be trusted and moreover have no reliability test arrangement so it becomes just a "assuming" game, until it's all over.

The circuit of a Simple AC Mains Surge Protector Device below, which shows how to make a simple homemade AC mains surge protector device is based on very simple principle of "speed breaking" the initial jolt through components who are well equipped in the field.

A simple iron resistor and MOV combination are more than enough to provide the protections we are looking for.

Here R1 and R2 are 5 turns of iron wire (1mm in diameter) over a 1 inch air core each followed by an appropriately rated varistor or an MOV connected across them to become a full fledged spike protector system.

Surge entering the input of spike  are effectively tackled and the "sting" absorbed in the course by the relevant parts and a safe and clean mains is allowed to go through the connected load.


An e-mail from one of my followers:

Hi swagtam,

 I found your email address from your blog. I really need yr help. Actually my company has customer in china we make UV lamps and we use electronic ballast for it. now the problem is in china because of Over Voltage the ballast burn out so i design circuit which is in attachment which dosen't help either?
so i found your
Ultimate High/Low Voltage Protector Circuit which i wants to build. or can you tell me the update if i can do in my circuit that will be great.
sorry if i am bothring you. but i really really need yr help to save my job
thanks
Thank You
Krishna Shah

My Reply to Mr. Krishna:

Hi Krishna,

According to me the problem may not be with the voltage fluctuations, rather it's because of the sudden voltage surges that's blowing of your ballast circuit. 

The diagram shown by you may not prove very effective, because it does not incorporate a resistor or any kind of barrier with the MOVs. You may try the following circuit, introduce it at the entry point of the ballast circuit. Hope it works:







47 comments:

  1. Hey swagatam, can this circuit be incorporated into the over and under voltage protection circuits you talked about at: http://www.brighthub.com/engineering/electrical/articles/68396.aspx

    ReplyDelete
  2. Hi Bourgeoisie,

    Yes, it can be incorporated in the over voltage protection circuit.

    Welcome to Swagatam's Homemade Circuit Blogspot :-)

    Thanks for visiting!

    ReplyDelete
  3. thank you sir. i will try and let u know.

    ReplyDelete
  4. Hello Sir

    I just have one question the circuit shown above i should connect it between Line -neutral am i correct?

    ReplyDelete
  5. Hi Kristin,
    Yes it is to be connected to the LIVE and Neutral input mains voltage.

    ReplyDelete
    Replies
    1. HI sir!

      Sir can i connect this circuit in line 1 to line 2 with ground main voltage? What i mean is the main voltage, line1 to ground = 110v, line2 to ground = 110v, line1 to line2 = 220v.

      Thanks

      Jojo l.

      Delete
  6. Hello sir,

    how to decide value of fuse? in any circuit and also what value of fuse can we use in above ckt if mains voltage 230v.

    thanks

    ReplyDelete
  7. Hi Kristin,

    The maximum safe current is the fuse rating that must be used.
    So if suppose your max allowable current is say 15 amps, then you use a 15 amp fuse and so on.

    Regards.

    ReplyDelete
  8. Hi Swagatam,

    Can you able to help me to make LI-ON and NI-MH battery charger using induction charging? I don’t know how to do it. I have Li-on battery with 3.6V and 2000mAh.Please can you help?

    ReplyDelete
  9. Hi Kristin,
    Please provide some more specs about the circuit, so that I can come up with an appropriate design.

    Regards.

    ReplyDelete
  10. ok i have to one project which is i wants to connect one UV LED to a circuit and from that circuit i connect that to NI-MH or LI-ON rechargeable battery and whenever charfe is not there through indication LED we can put that Whole unit for charge in HOlder which is made of Induction. i mean we can do induction charging.

    right now i don't know much about LED specs. i will let you know by tomorrow. so you can help me.

    thank you very much

    ReplyDelete
    Replies
    1. Hi Kristin,

      This concept is new to me and I haven't done any practical project involving magnetic induction, I'll try though, but I cannot guarantee the results.
      I'll post the design soon within a couple of days, just check back in-between.

      Regards.

      Delete
    2. in short i need to make a design which is for chraging any NI-MH battery. also i found that charging ckt for LI-on will be different from NI-MH. because overchraging may explode LI-ON battery.

      one LED(not UV) has 3.6voltage and approx. 700-1000mA current. also NI-MH battery is 3.6v and 2000mAH. actually below i copied the battery details.

      Features and Benefits

      •High quality 1.2 V 4/5 A 2000mAh rechargeable Nickel Metal Hydride (Ni-MH) battery
      •High capacity (2000mAh)
      •Make your own battery packs in any combination of shape and voltage with easy soldering
      •Ideally suitable for making mini battery pack for remote controlled (RC) aircraft.
      •Ultra high capacity, 40% more running time than Ni-Cd battery.
      •Very long cycle life and Rapid battery charge up
      •Significant savings (60 % or more) from any retail stores.
      •Battery tested based on International Electronic Commission (IEC) standard to ensure capacity, quality and life time.
      •6 months warranty.
      Technical Specifications

      •Dimension: Height 43 mm, Diameter 17 mm
      •Weight: 30g.
      •Capacity: 2000 mAh
      •Voltage: 1.2V
      •Standard Charge: 20 hours @ 100 mA
      •Rapid Charge: 2 hours @ 1000 mA

      Delete
    3. Hi Kristin,
      The above specs are all known to me, so it was not required.... I wanted to know about the circuit that you want, do you want just an automatic Ni-Cd charger circuit?

      And what is role of the UV LED,

      Please explain all these in steps, how do you want the circuit to function?

      I have already published one article related to induction charging, you can find it in the blog homepage.

      Regards.

      Delete
  11. Hi Swagatam,
    it is a flashlight which has a Blue LED.Right now i use 1 Ni-MH battery to run that LED no Circuit. But now i need a circuit which i use to run LED and also an induction charging circuit to charge the NI-MH battery.

    thanks

    ReplyDelete
    Replies
    1. Hi Kristin,

      I can design the charger and the LED driver circuit, but the induction charging system will be difficult, because I'm not entirely familiar with the concept.

      Regards.

      Delete
  12. Ok. If you can give me that.

    Thank you very much

    ReplyDelete
    Replies
    1. Hi Kristin,

      I'll do it within a couple of days and publish it.

      Regards.

      Delete
  13. Hey,

    May I know why you need two MOV's and two resistors between them?

    ReplyDelete
    Replies
    1. just for extra safety, even a single one will mostly do.

      Delete
  14. Thanks for your response. I'm sorry if my questions sound dumb to you, most of the surge related terms are new to me.
    As regards to my question earlier, wouldn't there be some voltage drop across a resistor. So why would be we wasting some power there. And why would we need a resistor on the neutral?

    I have noticed that you have two or three surge protection ckts on this blog, do any of them will pass surge voltage of 500V-6000V?

    ReplyDelete
    Replies
    1. The resistor value can be calculated and adjusted as per the load current, in fact the resistor is introduced for dropping voltage during higher voltages and thus safeguarding the load from the inrush.

      500V and above voltages are far too high, and probably not applicable for circuits presented in this blog by me...

      Delete
  15. Hi... about the surge protector you gave to krishna, can i incorporate it to my existing AVR for additional protection of my HDTV?

    ReplyDelete
    Replies
    1. Please indicate which circuit you are referring to.

      Delete
    2. sir, the surge protector i'm talking about is the one with two MOV and two 10ohm 2watt resistor. or sir can i ask a surge protector design that works with my HDTV with 220V working voltage? what would be the recommended MOV values?

      Delete
    3. The above circuits have not been verified practically, so I would suggest that you buy a "spike buster" from the market, because it is your costly HD TV that is at stake.

      Delete
  16. I want to design A PCB board

    The board must have the dimensions shown in the drawing. Only the area 1.250 X 0.800
    will be populated

    1. Act as a voltage indicator:

    Below a certain voltage (12-12.5V), the led will be RED.
    Over a certain voltage (12-12.5V) the led will be GREEN.

    2. It will monitor the current of one or two fans

    If one fan fails under a one-fan operation (no current draw), the LED will flash RED
    One fan will draw 0.075A

    If either fan fails under a two-fan operation (no current draw), the LED will flash RED
    One fan will draw 0.075A
    The other 0.12A

    ReplyDelete
    Replies
    1. I'll try to design it, if it's feasible for me I'll inform you.

      Delete
  17. Sir,

    Good day! How would I design a surge protection circuit without causing any effects in the voltage (e.g. voltage drop across the resistor)? We are developing a power quality meter and will incorporate a surge protection in the high side of voltage sensing circuit.

    Thanks!
    -Pierre

    ReplyDelete
    Replies
    1. You can incorporate thermistors and MOVs together, resistors can be avoided then.

      for knowing more about thermistors, you may refer to this article:

      http://homemadecircuitsandschematics.blogspot.in/2013/02/using-ntc-resistor-as-surge-suppressor.html

      Delete
  18. Can U plz. provide ckt. diagram of suge protector including EMI/RFI filter with 230V AC line tester.

    Thanx in Advance

    ReplyDelete
    Replies
    1. For what application do you want to use it?

      Delete
  19. I want it for PC, i already have ups but some times when mains fails PC restart and i think it is due to Spike problems.
    Thanx for your reply.

    ReplyDelete
    Replies
    1. No it's not due to spike, it's due to a split second late response from the UPS, try with a new good quality UPS and you won't find this issue happening.

      Delete
  20. sir can i use this circuit as telephone surge protector

    ReplyDelete
    Replies
    1. telephone surge protector?? i didn't get the application, can you pls explain it?

      Delete
  21. Hi....Swagatam can u give the VA rating of mov & fuse of above ckt u used above....when my ckt I/p current is 130mA and o/p current is 170mA & o/p voltage is 167 when I/p voltage is 230V for electronic ballast. ....so please share it with me asap....

    ReplyDelete
    Replies
    1. Hi Shersingh,

      you can use a 350V RMS, @5amp rated MOV.

      Delete
  22. Hi,

    Is it possible to use this diagram for a single wire ground return system? My power line is a single phase 240V and the neutral is coming from a copper rod in the ground. The voltage fluctuates a lot and i would really like to protect my devices (Mainly motors and VFD's) and some computers. Do you recommend any other systems like high and low surge protection? Also, what protection rating should i expect (high voltage vise)

    I appreciate your response in advanced.

    Chris

    ReplyDelete
    Replies
    1. Hi,
      the above circuit will only help to control surge in-rush to some extent but won't control the voltage fluctuations.

      you would need a voltage stabilizer circuit for tackling the issue effectively, one design has been discussed below which may be tried or procured readymade:

      http://homemadecircuitsandschematics.blogspot.in/2011/12/how-to-make-accurate-7-stage-op-amp.html#uds-search-results

      Delete
  23. Hi Swagatam ,

    How are you ? hope doing well.

    If want to draw constant 220 v AC at any point

    Generally input is
    Low - 110v / 130v AC
    High - 230/260 v AC

    Required Output
    220 V AC (Stabilized)

    Can you please suggest best circuit . if Tranformerless will preferable.

    Thanks
    Nilesh Patil

    ReplyDelete
    Replies
    1. Hi Nilesh,

      I am fine, thanks!

      You can try the design that's shown in the following article:

      http://homemadecircuitsandschematics.blogspot.in/2011/12/how-to-make-accurate-7-stage-op-amp.html#uds-search-results

      a transformerless design could be very difficult since it would involve complex mosfet drivers, ferrite inductors etc, so I think using the traditional iron core transformer would be much easier, although a little bulky.

      Delete
  24. Plz. value of MOV and best one company product......thnx.

    ReplyDelete
    Replies
    1. company is not important as all are good, the clamping voltage rating should be 50 V more than the input mains supply voltage.

      Delete
  25. Value of MOV and best company product....thnx.

    ReplyDelete
  26. Hi Mr Swatam. Cogratulation for your extraordinary electronic web page.......

    I write from México. My question is: For a 120v nominal voltage, what should be the value of the resistors, and the maximun peak voltage and Joules for the MOV's ?

    Thanks in advance for your help.......

    ReplyDelete
    Replies
    1. Thanks Roberto,

      for 120V you can select 200V as the clamping voltage for the MOV, the resistors are not critical they are just for complementing the MOVs, any value between 0.5 ohms to 1 ohms will do the job.

      10 ohm is far too big and must not be used, it's incorrectly shown in the diagram.

      Delete

Readers are requested not to include external links while commenting. For consulting a diagram, upload it on Google Drive and provide the link here.


Readers are advised to proceed with the construction of the presented circuits only after understanding the concepts from the core. Not adhering to this can lead to failures and frustrations.