Having bought quite a few of the in-car ozone generating plugs from ebay and other sellers in the hope of getting one that wasn’t actually fake, I finally got a real one. I can’t tell you which exact supplier it came from, since I received two identical black ones from different suppliers so far, so I’m not sure which one the real version came from.
There are quite a few more still to arrive, so if there are any other real ones with different circuitry I’ll tear them apart too.
Inside is a very generic high voltage inverter like the ones used to light cold cathode tubes (CCFL) for PC case decoration.
These circuits use a Royer configuration to drive a transformer in a push-pull configuration using two transistors and a feedback winding.
The transformer has a primary section and a multiple of secondary sections to provide better winding separation due to the high voltage being generated.
The output has a series capacitor for current control and one leg goes to both the connections of a standard neon indicator lamp (blue in this instance), while the other grounded end of the transformer is attached to a small tube of stainless steel mesh around the outside of the lamp.
The high voltage couples from the electrodes in the lamp to the entire inner surface via the internal gas, and the charge then alternates capacitively between the inside of the lamp and the outer metal mesh creating an area of corona discharge that splits oxygen molecules (O2) apart, before they recombine randomly as O2 and O3 which is ozone. Ozone is unstable and needs to get rid of the third molecule of oxygen, so it tends to attach onto any receptive surface, oxidising it in the process. This is what also gives the fresh bleach-like smell (which was very noticeable!)
The cases of these things are identical and even the circuit board shape and connection springs are clear copies. So it’s hard to tell what’s fake and what’s real without looking into the end of the module. The fake ones have a diffused blue LED in the end while the real ones have a glass lamp with a pip at the end and a very noticeable metal mesh round the lamp.
Most of the fake unit sellers on ebay use stock images of the real thing in its packaging, but some sellers show pictures of the actual units from various angles. By looking closely you may be able to see the LED or mesh covered lamp in the end. Although that doesn’t guarantee that they may send a real unit or whatever stock they could get cheapest.
