From: "Steve Andrew"
Subject: Re: Negative ion generators
X-Newsreader: Microsoft Outlook Express 5.00.2615.200
Date: Fri, 13 Sep 2002 02:23:34 GMT
NNTP-Posting-Date: Fri, 13 Sep 2002 12:23:34 EST
Organization: BigPond Internet Services (http://www.bigpond.net.au)
GregS wrote in message
> In article ,
email@example.com (Jason Hsu) wrote:
> >Exactly what voltage and current levels do I need?
> >I would like to build a negative ion generator. From what I
> >understand, a negative ion generator has a very high voltage
> >(thousands) and a very low current. This voltage is fed into a
> >very-high-voltage diode (oriented to pass the negative voltage but
> >reject the positive voltage). The resulting very high negative voltage
> >is fed into a very sharp object (such as a sewing needle), which
> >injects the negative ions into the air inside the chassis. A nearby
> >fan disperses the negative ions into the air in the room outside the
> >Exactly what voltage and current levels do I need? (I also realize
> >that I must simulate this in PSPICE, because the tiny current levels
> >and huge voltage levels aren't in a range that regular multimeters can
> >handle.) I have heard that using too much power will produce ozone,
> >which is poisonous.
> Emulate? A good potential is 6-9KV. Current is microamps, maybe
> 50-500 depending on the emitters and grounds nearby. A DC source is
> However which way you do it, diode, diodes. Negative of the supply goes
> to the emitters, needles, wire brush, etc. The positive terminal gets
> referenced to AC ground. Its a good idea or necessary to add series
> resistance, so a finger on needle will get less than 1 Ma. preferably less
> than 500 microAmps. A fan is unecessary. It blows air anyway. A fan
> can be used to force surrounding air through and land upon a slighty
> conductive element or just metal. The debris just sticks to all you walls
> otherwise. It will do it anyway. If the voltage is too high or a ground is
> too close to the needles, an arc can try to occur which will produce
> Ozone. Ozone needs carefull attention but is an otherwise
> excellant odor eliminator, preferably used in an unoccupied space,
> or while you are away. You like the smell of the sun through a window?
> Ion generators can reduce odors slightly.
I've seen ion generators running directly of 240VAC mains supply using
something like a Cockcroft-Walton or Villard voltage multiplier. You can get
a circuit for the more commonly used Villard cascade multiplier from