Two models will be shown, one full-wave rectified and the other a half-wave rectified negative ion ionizer. Featuring an optional fan on the full-wave model. Benefits of negative ions supposedly include • freshen and purify the air • help lift mood • alleviate depression including winter depression(SAD) • eliminate most tiny particles suspended in the air (indoors)CAUTIONHIGH VOLTAGESpresent in both devices is high enough to induce a bad case of temporary Tourettes. Be aware of the hazards when working with loose CARBON FIBRE filaments if using this option for high voltage grid instead of pins. Step 1: Components and DesignShow All ItemsTools required: soldering iron and solder. screwdrivers, flat and star hot melt glue gun. The full wave rectified version has better performance but is a bit noisier if using the optional fan. The fan is a 60mm x 60mm CPU 12 brushless fan which I'm driving at 5v to reduce current consumption and noise. The half wave version uses fewer components and less current, the smaller size is also trickier to build.

In both versions the negative band on the diode must point towards the ac voltage input. If you follow the green arrows on the component diagrams, you will first encounter the negative side on the diode first, indicated by the white band.« air cleaner in basementPreviousNext »View All Steps Downloadair cleaner for throttle bodyThe air inside an average home overflows with pollutants, bacteria, and other harmful particles. best lens wipes for glassesThis is why air purifiers are invaluable for people with allergies and respiratory ailments such as asthma. The most common method of purifying air is with filters. Ionic air purifiers use a more complex method than mere filters and reduce contaminants using charged particles.

Understanding the basics of how ionic air purifiers work helps buyers make more informed decisions regarding their purchases. Molecules make up all the particles in the air, including contaminants. These molecules have a stable, neutral charge. Most air ionizers use a process called corona discharge to create negatively charged air molecules. To achieve a corona discharge, air ionizers use several rows of needle-like structures. High electric voltage (with a low current) passes through these needles. Because electrons have a negative charge, they repel each other until they reach the tip of the needle and break free. The free electrons cling to the nearest air molecule, giving that molecule a negative charge and turning it into an ion. Because negatively charged particles repel each other, these ions push each other away. As a result, they disperse in all directions without the need for a motorized fan or any other dispersal system. When an ion encounters another molecule, it passes on its negative charge.

Contaminants usually consist of large molecules, and ions easily bump into them. The negatively charged contaminants seek a grounded surface, such as a wall or the floor. Modern ionic air purifiers include built-in collector panels that act as magnets for these charged contaminants. Because air ionizers work at a molecular level, they can remove even the smallest contaminants, including germs, bacteria, and viruses. According to an article in The New Scientist, ionic air purifiers can wipe out even antibiotic-resistant bacteria present in public hospitals. However, critics of these purifying systems point out the lack of extensive testing on this technology and insist poorly designed units can prove hazardous to users' health. Because the contaminants stick to floors and walls as well as the collector panels, users have to clean the units and their homes regularly. Not doing so allows the contaminant particles to re-pollute the air. Compared to other air purifiers, air ionizers are the most well-rounded and efficient systems available.

Although other air purifiers are more effective in some cases, they typically have a narrow range of very specific uses. Purifiers that use ultraviolet light, for example, kill microorganisms but fail to handle dust and smoke. Type of Air Purifying System Can remove particles up to 0.01 microns Can remove bacteria and viruses Most units are easy to clean Contaminants could return to the air without frequent cleaning of rooms and collecting panels Badly-designed units could produce harmful ozone HEPA Filter Air Purifiers Can remove particles up to 0.03 microns Filtered contaminants not re-released into the air Cannot filter smaller contaminants such as cigarette smoke Filter is sometimes a breeding ground for microorganisms Can remove odors, fumes, and smoke Filtered contaminants not re-released into the air Cannot remove larger particles such as dust and other allergens Cannot remove bacteria and other microorganisms Sterilizes bacteria, molds, and viruses

Cannot purify dust and other allergens Cannot remove odors, fumes, and smoke Some ionic air purifiers are actually hybrids that contain additional purifying methods, such as pre-filters with activated carbon. This makes the systems more effective at cleaning the air. Buyers can start their search for air purifiers on eBay. Typing "ionic air purifier" into the search box found on any page typically provides users with hundreds of results. Adding additional details, such as a brand name, helps buyers find listings that are more precise. Search terms such as "Ionic Pro air purifier" or "Sharper Image air purifier" yields fewer results but are more specific concerning the buyer's needs. Buyers should read the product pages and the seller's policies very carefully, especially for used air purifiers. Although the operation of air ionizers may seem too complex for average buyers to understand, it is actually just basic science. Air ionizers apply high voltage through several needles to create negatively charged air molecules.