Air Ionizer, Ozone and Negative Ion Generator Cautionary Safety Statement


This Cautionary Safety Statement is issued in response to the reported failure of a Rhythmedics Metronome when operated in close proximity to a High Energy Discharge Device (HEDD), such as an Air Ionizer, Negative Ion Air Purifier, Ozone Generator or Negative Ion Generator. These devices use very high voltage, in excess of several thousand volts, to emit a continuous stream of charged particles (anions or cations) which may behave like a static electricity.  HEDDs are normally safe to use when following the manufacturer’s guidelines. However, there are some precautions that should be followed when they are used around electronic instruments.
The subsequent evaluation and testing of the returned instrument  and subsequent testing of all Rhythmedics instruments operating in close proximity to the same model of HEDD has prompted NuTesla to recommend the following cautionary safety measures for any Rhythmedics instrument used in the same room with a HEDD.
  1. Do not connect the Rhythmedics instrument’s AC Power adapter into the same AC circuit as the HEDD. The use of a Surge Protector power strip does not provide adequate isolation to overcome this restriction.
  2. Do not place the Rhythmedics Instrument or its AC Power Adapter within 2 meters (6 feet) of the HEDD or its generated output of ions.  Never place the Rhythmedics instrument anywhere below the HEDD or in the path of any forced airflow emitted from some types of HEDDs.
  3. If the Rhythmedics instrument must be operated within the same room as the HEDD, use a grounded USB power source to operate the instrument, such as from a desktop computer that is connected to the house wiring using a third wire grounded (3 prong) electrical connector.
Background Information and Analysis of the Failure
A customer reported a Metronome Pro, while connected to its AC charger and operated continuously on a nightstand next to a Negative Ion Air Purifier, became very hot to the touch and a spark was observed when the user unplugged the charger from the Metronome Pro.  The Metronome Pro and its AC charger were returned and evaluated and it was discovered the Battery Management Integrated Circuit that connects directly to the AC charger had failed in such a manner as to damage the internal rechargeable battery, causing it to overheat.
The negative ion generator is capable of producing a continuous stream of 100 trillion negatively charged particles every second in the range of 4,500 volts to 6,500 volts.  Connecting the Metronome’s charger and the Negative Ion Generator into the same AC electrical circuit created a return path with an electrical field which exceeded the manufacturer’s stated “Absolute Maximum” rating for the Battery Charge Management Integrated Circuit, causing a failure of the management chip and damaging the rechargeable battery.

All NuTesla instruments contain internal safety circuits designed to open power pathways should a failure occur. While the customer reported the Metronome was hot to the touch, none of the internal failsafes were tripped, indicating the failure was limited and there was no risk of a fire. By way of illustration, paper ignites at 541° Fahrenheit and the safety circuits activate before the temperature can reach 200°, well below any fire hazard. The user did not report any burns to the skin.

Subsequent retesting of all NuTesla instruments in close proximity to the same HEDD, revealed two other nuisances which occurred. These are classified as nuisances as the effects of the HEDD were temporary and the instrument returned to normal operation with thirty minutes after being moved outside the 2 meter range recommended above.

The first nuisance affected Somnius and Clarius, both of which developed an audible high pitch tone occurring when it was operated within three feet, one meter, of the HEDD and when plugged into the same AC power outlet circuit.

The second nuisance was with regard to the operation of Pendulum after being held within a few inches of the output field of the HEDD causing the Pendulum to retain an external electrical charge that created static electric shocks to the wearer when worn with the included metal beaded necklace.

In neither of these nuisance cases were any damages retained by the exposed devices, and all instruments returned to normal operation after being removed from the affected field of the HEDD.