7. EMC statements
This portion of the content will provide the user with basic information
that describes the problems with EMI, known sources of EMI, protective
measures either to lessen the possibility or exposure or to minimize the
degree of exposure, and suggested action should unexpected or erratic
movement occur.
Caution
: It is very important that you read this information regarding
the possible effects of electromagnetic interference on your electric
TP
01-S
WHEELCHAIR.
■
ELECTROMAGNETIC INTERFERENCE (EMI) FROM RADIO
WAVE
SOURCES
Powered vehicle 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 directions. It can also
permanently 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 a 20 V/m immunity level,
which would provide useful protection from the more common sources
of radiated EMI. This powered vehicle model as shipped, with no
further modification, has an immunity level of 20 V/m without any
accessories.
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 warning
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 ( transmitter-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.
P19
