I did some digging on the subject of ionizers. It looks as if a high voltage (several kV) is applied to an array of needles (this concentrates the electrostatic field to facilitate ionization). There's only one "electrode" not a pair (as far as I can tell). This is not the same as an ozone generator.

the link below is for the core high voltage device and needle array, for $4.50.

: Hi there.

: My impression of these ionizers is that they are simply a device which
: creates a small constant (more-or-less) spark which creates ozone which
: ultimately helps neutralize the slightly charged dust particles so that
: they are not attracted to our boats. Add a small fan for circulation,
: maybe a paper filter just to get the big stuff out of the air, and that's
: it.

: How's it look to you; have you had the cover off it yet?

: Pete,
: in Snohomish, WA