Negative Ion Generator

How Negative Ions Purify the Air

Virtually all particles in the air have a positive charge, while negative ions have a negative charge. In which case, negative ions and particles magnetically attract to one another. When there is a high enough concentration of negative ions in the air, they will attract to floating particles in large numbers. This causes the particle to become too heavy to remain airborne. As a result, the particle will fall out of the air, preventing it from being inhaled into the respiratory tract where it can trigger breathing and health problems.

The ionized particle will then be collected by normal cleaning activities, such as vacuuming or dusting. If the particle happens to be kicked back up into the air again, it will be ionized, and quickly settled out of the air once again.

 Air Ionizers  electrodes needlepoints produce negative ions. This method produces a density (about 1,000,000/cm3) that is comparable to the world's largest waterfalls, such as Niagara Falls, which offers one of the healthiest environments in the world. (Effects of Negative Ions)

Other Negative Ion Benefits

High levels of negative ions drastically or significantly reduce asthma and allergy symptoms, as well as respiratory-related illness.

Migraine Headaches. Inhaling negative ions prevents the production of Serotonin inside the brain. The overproduction of Serotonin inside the brain is the cause of migraine headaches.

Depression. A study at Columbia University suggested that negative ion treatment is more effective than anti-depressant drugs such as Prozac and Zolof, and there are no side effects with negative ions.

Fatigue. The production of Serotonin (chemical produced inside the brain) also causes fatigue, and negative ions prevent the production of Serotonin inside the brain.

Sleep. A study in France found that negative ionizers helped people to sleep better, by preventing the production of the chemical Serotonin in the brain.

Mental Performance and Concentration. Several tests have shown people exposed to negative ion treatment perform much better in mentally-oriented activities than those who are not.

Physical Performance. Due to test results performed by Russian scientists, negative ionizers were always installed in the locker rooms and resting places for the Russian athletes.

Burns. Studies performed in one hospital found that burn patients were far more likely to recover more quickly and thoroughly.

The design of the Negative-Ion Generator is fairly straightforward  The circuit is a high voltage generator. It contains a standard 555 timer that's used to generate square-wave pulses. The pulses are applied to the base of the TIP120 NPN Darlington transistor. The Darlington provides sufficient current to the base of the 2N3055 power transistor to turn it on. Each time that happens, current flows through the high voltage auto-transformer, T2. The high voltage lead of the transformer is connected to a 10 kilovolt high voltage diode. Notice the polarity of the diode. It is biased to place a negative charge on C3 and C4, leaving the discharge point negatively charged. The voltage at the discharge point negatively charges the air forced past it by the fan.
The author's prototype was built on sections of perfboard using point-to-point wiring. It is a suitable method that you can use in your won ion generator provided you follow some precautions: Make sure you place C3, C4, D1, and the discharge point (which we'll describe momentarily) on a piece of perf board all their own. The junctions between those components should be at least a centimeter (about 1/2-inch) apart. Both this little high voltage board and the autotransformer should also be kept at least 1 centimeter away from the perfboard containing the other components, the fan, and the power transformer.
In passing, if you chose not to buy D1 from the supplier (1992) mentioned in the Parts List, an exact replacement may be difficult to locate. However, even though it has a lower current rating, an ECG518 or NTE518 should work fine, although this substitution has not been tried.
The discharge point should be "pointy" to enhance the ionization of the air. You can use a sewing needle, for example. An alternate discharge point can be fashioned from a small piece of No. 22 stranded wire. Strip off about 1/2-inch from one end of the wire and separate the fine copper strands so that they are more of less evenly dispersed. When the wire is connected to the high negative voltage, the end of each strand will behave as a discharge point.
Any screen or covering on the fan-outlet hole should be non-metallic or plastic in nature. Using a metal screen would severely cut the efficiency of the generator because the negative ions that come into contact with the metal screen would be neutralized.
When testing the circuit, if you see any arcing or discharge from the high voltage transformer or high voltage capacitors, cut the power immediately. Let the project sit for awhile to let the capacitors discharge, and, without touching the project if possible, coat the faulty are with a little "No Arc" spray (available from Radio Shack or Tandy). Allow the material to dry before testing the unit again.
(Tony's comment: The ECG518 and NTE518 are still available, the added bonus is that the ECG/NTE518 supplies 25mA instead of 10mA by the IMD5210).

Parts List:
   R1 = 15K, 1/4W, 5%
   R2 = 1K, 1/4W, 5%
   R3 = 2.2K, 1/4 W, 5%
   R4 = 470, 1/4 W, 5%
     
   C1 = 1000uF/25V, electrolytic
   C2 = 0.047uF, polyester-film
C3,C4 = 0.002uF, 6000WVDC, ceramic disc

   U1 = 555 timer, 8-pin IC (no CMOS)
   Q1 = TIP120 or NTE261, NPN, Darlington transistor
   Q2 = 2N3055, NPN, power transistor
   D1 = 10,000 Volt, 10mA, SI rectifier diode (see text)
  BR1 = 4A, 50-PIV bridge rectifier

Additional Parts and Materials:
  T1 = 12 volt 1.2A, power transformer
  T2 = 12 volt to 8 kilo volt autotransformer
FAN1 = 12 volt DC fan.
Enclosure, line cord, switch, TO-3 socket/heat sink, perfboard, wire, solder,
hardware, etc.