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CHAPTER 11 - EMI WARNING
All types of electrically powered vehicles, such as powered
wheelchairs and motorized scooters (in this text all types will
be referred to as “powered vehicles”) may be susceptible to
electromagnetic interference (EMI), which is interfering
electromagnetic energy (EM) emitted from sources such as
radio stations, TV stations, amateur radio (HAM) transmitters,
two way radios and cellular phones. The interference (from
radio wave sources) can cause the powered vehicle to release
its brakes, move by itself, or move in unintended direction. It
can also damage the powered vehicle’s control system. The
intensity of the interfering EM energy can be measured in volts
per meter (V/m). Each powered vehicle can resist EMI up to a
certain intensity. This is called its “immunity level”. The higher
the immunity level, the greater the protection. At this time,
current technology is capable of achieving at least 20 V/m
immunity level, which would provide useful protection from the
more common sources of radiated EMI. This SUPERLIGHT as
shipped with no further modification, has an immunity level of
20 V/m.
There are a number of sources of relatively intense
electromagnetic fields in everyday environment. Some of this
sources are obvious and easy to avoid. Others are not apparent
and exposure is unavoidable. However, we believe that by
following the warning listed below, your risk of EMI will be
minimized.
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: citizen band (CB) radios, “walkie
talkies”, 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.
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