How does a negative ion generator work?

[gabee]

Like this one:

http://www.goldmine-elec-products.com/prodinfo.asp?number=G9695

I understand that it uses some sort of "needle assembly," and electric fields are stronger at sharp points in a conductor and then will ionize the surrounding air at a certain potential. But how exactly are the negative charges isolated in the first place? Some friends and I have discussed how this might happen, such as first charging a capacitor, then attaching the negative lead to such a needle assembly, then grounding the positive lead, but we're not exactly sure.

 

[Mentz114]

I believe the ionisation is caused when an electron binds loosely with a gas molecule. If you put a high -ve voltage on a needle, electrons can escape from the point.

Some friends and I have discussed how this might happen, such as first charging a capacitor, then attaching the negative lead to such a needle assembly, then grounding the positive lead, but we're not exactly sure.

That's about right. The voltage can come from any source, with the +ve grounded.

 

[charng]

A negative ion generator works by using a high-voltage power source to create a strong electric field at the sharp points of a needle assembly. This electric field causes the air molecules around the needles to become ionized, meaning that they lose or gain electrons and become either positively or negatively charged.

The negative charges are created by the sharp points of the needle assembly, which act as a collector for electrons. As the electric field becomes stronger, the electrons are pulled towards the needle points and are then released into the air, creating a stream of negatively charged ions.

This process is similar to how a capacitor works, where one plate becomes positively charged and the other becomes negatively charged. In the case of a negative ion generator, the needle assembly acts as the negatively charged plate, while the surrounding air acts as the positively charged plate.

The grounded positive lead in the setup you described helps to balance the charges and maintain a stable electric field. As the negative ions are created and released into the air, they are attracted to the grounded positive lead and are then dispersed into the surrounding environment.

Overall, a negative ion generator works by creating a strong electric field at the sharp points of a needle assembly, which ionizes the surrounding air and releases negatively charged ions. This process helps to purify the air and can have potential health benefits for those who are exposed to the negative ions.