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The sources of radiated EMI can be broadly classified into three types:
1) Hand-held portable transceivers (transmitters-receivers) with the antenna
mounted directly on the transmitting unit. Examples include: citizens band
(CB) radios, “walkie talkie,” security, fire, and police transceivers, cellular
telephones, and other personal communication devices. **Note: Some
cellular telephones and similar devices transmit signals while they are ON,
even when not being used.
2) Medium-range mobile transceivers, such as those used in police cars, fire
trucks, ambulances, and taxis. These usually have the antenna mounted on
the outside of the vehicle; and
3) Long-range transmitters and transceivers, such as commercial broadcast
transmitters (radio and TV broadcast antenna towers) and amateur (HAM)
radios.
Note: Other types of hand-held devices, such as cordless phones, laptop
computers, AM/FM radios, TV sets, CD players, and cassette players, and
small appliances, such as electric shavers and hair dryers, so far as we know,
are not likely to cause EMI problems to your powered wheelchair.
Powered Scooter Electromagnetic Interference (EMI)
Because EM energy rapidly becomes more intense as one move
closer to the transmitting antenna (source), the EM fields from Hand-held
radio wave sources (transceivers) are of special concern. It is possible to
unintentionally bring high levels of EM energy very close to the powered
scooter’s control system while using these devices. This can affect powered
scooter movement and braking. Therefore, the warnings listed below are
recommended to prevent possible interference with the control system of
the powered scooter.
WARNINGS
Electromagnetic interference (EMI) from sources such as radio and TV
stations, amateur radio (HAM) transmitters, two-way radios, and cellular
phones can affect powered scooter and motorized scooters. Following the
warnings listed below should reduce the chance of unintended brake release
or powered scooter movement, which could result in serious injury.
1) Do not operate hand-held transceivers (transmitters-receivers), such as
citizens band (CB) radios, or turn ON personal communication devices,
such as cellular phones, while the powered scooter is turned ON.
2) Be aware of nearby transmitters, such as radio or TV stations, and try to
avoid coming close to them;
3) If unintended movement or brake release occurs, turn the powered
scooter OFF as soon as it is safe.