Working Principle: By using pulses and vibration of electric appliances, rise the original low voltage to DC high negative pressure. Making use of DC high voltage of carbon brush tip to produce high corona, emitting large amounts of electronic at a high speed. Electronics can not remain in the air for a long time, therefore, after reacting with oxygen molecules in the air, negative ions will form.
I planned to built with this item an a portable personal air ionizer. For this reason take a photo (see below) to efficiency. Left meter a miliampermeter, the right meter a voltage meter. You see the current, voltage and emitted voltage.