This quick build allows me to extend the life of the P3 filters used in the face mask . Even with the inhale valves a small amount of warm , moist air from the lungs can still pass through the filters and promote the growth of the bacteria and fungi . In order to eliminate them I build a small ozone disinfection chamber .
The ozone chamber uses a corona discharge tube in order to produce enough ozone do fill a plastic container . The discharge tube is powered with high voltage pulses produced with an old car ignition coil.
The discharge tube is built using a ceramic or glass tube . Inside it a long threaded bolt is used as the ground electrode , while a stainless mesh is used as the high voltage electrode. The tube needs the voltage in the 10 kV range in order to operate.
The high voltage is produced using the car ignition coil . The coil is powered using a simple driver built using only discrete components . This way it can be built using parts which can be easily found in most of the electronic junk . Most of the components values are not critical , substitutes can be used. The maximal coil current is set with the value of the R6 resistor , while the pulse repetition frequency can be set with the capacitor C2.
The device has been installed on the lid of a small plastic container .