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How to Build an Ozone Water/Air Sterilizer - Disinfecting Water withOzone Power

We are all familiar with thundering and lightning during stormy weathers and know how the effect is responsible of producing a lot of ozone and negative ions in the atmosphere. The same concept has been employed in the proposed water and air sterilizer circuit.

Properties of Ozone

Ozone is a pale blue gas having a pungent order (akin to chlorine) with the chemical formula O3. In the atmosphere ozone may be produced due to the presence of strong UV rays or electrical discharges as during thunder lightnings.

The above mentioned phenomenon produce ozone basically by knocking down the dioxide oxygen molecules (O2) which are present plentifully in the atmosphere, resulting in O2 → 2O.
The resultant free radicals generated as 2O collide around the source forming  O3 or Ozone. The process continues as long as the source (lightning arcs, UV rays) keep their presence.

By nature Ozone is a very strong oxidant even stronger than dioxide. This property of ozone is helpful in killing germs, parasites and other microorganisms which may be regarded as pests and hence is used as sterilizer for disinfecting water and air.

However, the strong oxidizing property of ozone could be also harmful for humans and animals and could cause respiratory issues if inhaled for longer periods of time inside a non-ventilated premise.

The above discussion shows that ozone can be actually produced very easily either through unsuppressed arcing or through UV rays and used for sterilizing water or air appropriately.

Implementing Unsuppressed Spark Arcing

In the proposed design we incorporate the unsuppressed arcing method since it's more effective and easily implementable.

Producing artificial arcing can be simply done by using a boost circuit topology wherein a high frequency is dumped into a booster coil for generating the required high voltages.

The resultant voltage being in kVs can be forced to arc by bringing the ground terminal close to the high tension terminal from the coil.

The best example of this could be a CDI circuit using the ignition coil as the kV generator, which are normally used in vehicles for generating ignition sparks inside the spark plug.

The following diagram illustrates how a CDI circuit may be used as a ozone generator for sterilizing water, air, food etc.

The lower 555 IC circuit is used for triggering TR2 which is an ordinary step down iron core transformer. It's primary is oscillated at its rated voltage through a frequency set by the 100k pot.

This results in the induction of 220V or whatever may the rating of the secondary high voltage winding of the transformer.

Using a Capacitive Discharge Circuit

This induced 220V is fed to the following CDI or the capacitive discharge ignition stage consisting the scr and the ignition coil as the main components.

The SCR along with the high voltage capacitor and the associated diodes fire at the given frequency forcing the 105/400V capacitor to charge/discharge rapidly, dumping the stored 220V at the same rate into the ignition coil primary.

The result is the generation of around 20,000 volts at the secondary high tension output of the ignition coil.

This output is appropriately terminated close to another terminal derived from the negative of the supply.

Once the above set up is configured, the arcing initiates instantly causing the ozone to be generated around the spark zone.

Since excess generation of the ozone could be harmful for the living beings in the premise, the circuit could be triggered through a programmable timer such that it stays switched ON only for some predetermined period of time and gets switched OFF automatically once the set time elapses.

This would ensure the safe amount of ozone to be produced in the premise.

The arcing may be introduced inside any chamber wherein the intended materials or ingredients may be placed and the unit switched ON for initiating the sterilizing actions through the generated ozone gas.

Circuit Diagram

Ozone Water/Air Sterilizer Circuit

Need Help? Please leave a comment, I'll get back soon with a reply!


  1. Please sir, i have a question about the Op-amp. My question is: If an op-amp is fed with a supply voltage of 9v for instance, can you generate more than that 9v at the output assuming the gain is properly defined? In simple words, can you generate 15v from 5v input in an Op-amp that is powered with a supply voltage of 12v? If yes, will the output current be significant?

  2. Dear Swagatam,
    This circuit can give High voltage with low frequency (between 50hz and 2000hz)?

    Thank you

  3. Dear Victor,

    yes, it has to be at lower frequency only, higher frequencies will heat up the ignition coil...

  4. Thank you for your quick response,
    Which is the capacity of the condenser near the diodes?
    And which amperage is recommended to have the 230v transformer?
    I will try it and let you know, thank you

  5. the capacitor is 105/400V or 1uF/400V metalized polyester type.

    the transformer could be a 0-12V/1amp

  6. Dear Swagatam,
    2 questions more sorry..
    All transformers (for buy) are AC/AC right?
    And how many volts should be in the part of 230 Volt of the transformer? like 230volts?
    Thank you

  7. Dear Victor,
    TR2 is an ordinary step down transformer with rating: 0-12V/1amp/220V

    the red one could be any standard automobile ignition coil...

  8. Good day swagatam ! I have a question how should i implement it to sterilize a water ? should i put the output directly to the water ? thanks for this.

  9. Thanks Ryan, just bring the high tension wire end near the ground wire through a needle arrangement such that these are held 1 inch apart or at a distance where arcing or sparking just initiates and is sustained.

    this arcing terminals can be enclosed inside a water tank permanently for executing the sterilizing action, the water may be kept in a cycling motion through a motor propeller mechanism for enabling an effective contact with the generated ozone atmosphere inside the container

  10. Thanks Swagatam ! I have another question, can you send me the link of the detailed schematic diagram ? i cant find it here in your site. thanks !

  11. Ryan, the detailed schematic is already shown in the above article, please click on the diagram to enlarge it.

  12. sir what are the IC used in circuit for a 30 gm ozonator

  13. Hello Swagatam.
    Nice project, I need your help for making this more powerful.
    Like if CDI is generating 20kv. How it can generate 50kv.
    Can you guide me please.
    Thanks and regards.
    Taibani Imran.

  14. Hello Imran, I think you can try replacing the shown motorcycle ignition coil with a car ignition coil and see the difference, because a car ignition coil would be much powerful than a motorcycle coil and produce stronger pulses.

  15. Hello Swagatam,
    Thank you very much for giving your valuable time in answering our questions.
    Need one more help please can you design Negative ion generator circuit with the input should DC not AC.
    Thanks and Regards.
    Taibani Imran.

  16. Hello Imran, I have a one circuit which will generate negative ion but with a low current, here's the link:

    such circuits will generally not work with DC, the DC will first need to converted to AC then applied to the circuit, as shown here


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