User's Manual
EW-M48
ELECTROMAGNETIC INTERFERENCE AND WARNINGS
3
CAUTION: It is very important that you read this information regarding the possible
effects of Electromagnetic Interference on your power chair.
Powered wheelchairs and motorized scooters may be susceptible to electromagnetic
interference (EMI), which is interfering electromagnetic energy (EM) emitted from sources
such a radio stations, TV stations, amateur radio (HAM) transmitters, two-way radios, and
cellular phones. The interference (from radio wave sources) can cause the motorized
scooter to release its brakes, move by itself, or move in unintended directions. It can also
permanently damage the motorized scooter control system. The intensity of the interfering
EM energy can be measured in volts per meter (V/m). Each motorized scooter can resist
EMI up to a certain intensity. This is called its "immunity level." The higher the immunity
level, the greater the protection will be. At this time, current technology is capable of
achieving at least a 20 V/m immunity level, which would provide useful protection from
the more common sources of radiated EMI. The immunity level of this motorized scooter
model is 20 V/m.
There are a number of sources of relatively intense electromagnetic fields in the everyday
environment. Some of these sources are obvious and easy to avoid. Others are not
apparent and exposure is unavoidable. However, we believe that by following the warnings
listed below, your risk to EMI will be minimized.
Some cellular telephones and similar devices transmit signals while
they are ON, even when not being used.
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.
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.
3.Long-range transmitters and transceivers such as commercial broadcast transmitters
(radio and TV broadcast antenna towers) and amateur (HAM) radios.
Because EM energy rapidly becomes more intense as one moves 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 power chair control system while using these devices. This can affect power chair
movement and braking. Therefore, the warnings listed below are recommended to prevent
possible interference with the control system of the power chair.
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 motorized scooter.
Power Chair Electromagnetic Interference
：
Electromagnetic interference (EMI) from sources such as radio and TV stations, amateur
radio (HAM) transmitters, two-way radios, and cellular phones can affect the power chair.
Following the warnings listed below should reduce the chance of unintended brake release
or power chair movement, which could result in serious injury.
Warnings
：
