User's Manual
HS-5600
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
Some cellular telephones and similar devices transmit signals while
they are ON, even when not being used;
EMI AND WARMINGS
3
It is very important that you read this information regarding the possible effects
of Electromagnetic Interference on your motorized wheelchair.
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
chair to release its brakes, move by itself, or move in unintended directions. It can also
permanently damage the motorized chair control system. The intensity of the interfering
EM energy can be measured in volts per meter (V/m). Each motorized chair 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 a 20 V/m immunity level, which would provide useful protection from the more
common sources of radiated EMI. This motorized chair was tested using the configuration
pictured on page 4. It had an immunity level of at least 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.
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.
