Auto transformer in a negative ion generator

[Abcdjkzero]

I'll put the link to the schematic I'm working with. I haven't started building it yet because I want to fully understand it.

http://www.sentex.ca/~mec1995/circ/hv/niongen/niongen2.html

In the schematic and parts list it's calls for a 12v to 8kilo volt auto transformer. Does this mean the transformer is meant to convert 12v to 8000V? That seems kind of ridiculous.

If I'm planing on not using mains supply to a transformer and bridge rectifier and using just 12vDC battery supply instead, can I still use the auto transformer?

I believe the purpose of the auto transformer is to increase the volts going through the rectifier diode and the 2 capacitors before discharging through the pin. Do I have other options?

I know this is a lot of questions and I can be way off. Any help from anyone would be appreciated. Working with electronics is somewhat new to me and I'm still learning. Also any videos or literature that would give me a better understanding of this would be great.

Mucho appreciation!

Shane.

[MJLorton]

Hello Shane,

I'm also looking into the topic of air purification so it was interesting to read about the project.

I think you'll find...and I'm no expert...that ionization requires those high voltages. If you drop the mains side (transformer and bridge) it should run off a 12v battery. Testing with a variable power supply should confirm that.

Cheers,
Martin.

[mariush]

Have a look at this old negative ion generator:

http://www.youtube.com/watch?v=OgynsEveujQ

They're using a Walton Cockcroft voltage multiplier to boost the 230-240v common in UK to several thousand volts, which is required for the needles to emit negative ions.

Yes, 8kv is quite possible, but you have to keep in mind that the current will be extremely small, and most likely your design will also have a resistor or two (in the range of 1gohm+) further protecting users... or some other protection method.