Theories Of Operation - Life Fitness E5 Service Manual

Theories of Operation

All electrical functions of the model E5 cross-trainer are controlled through the console and the Activity Zone.
Console
The console provides the primary interface for the user. The consoles have keys by which the user can select various
exercise programs and resistance settings (levels). The display shows speed, heart rate, resistance level and other in-
formation. For more specifi c details on the console including console displayed errors, please see the Go or Track Plus
Service Manuals.
The console has four connectors that attach to the product base.
1. An Activity Zone connector allows communication between the Activity Zone and the console.
2. The I/O Connector brings speed, resistance control and 9VDC power signals into the console.
3. The Contact Heart Rate connector brings signals from the hand sensors to the contact heart rate board located in
the console.
4. The ground connector grounds the console board to the base product.
Activity Zone
The Activity Zone supports a keypad interface to allow the user to quickly control the product's resistance level, stride
length as well as two program selections. There is a small microprocessor in the Activity Zone that runs the Leg Sculp-
tor Mode shown on the Activity Zone and also controls the stride length. The Total Body Mode and resistance levels
are controlled from the console. The Activity Zone also incorporates an LCD display that displays intensity level, stride
length as well as showing leg muscles normally used at different stride lengths. There is some back and forth communi-
cation between the Activity Zone and the Track Plus Console (No back and forth communication with the Go Console).
The Track Plus Console will adjust the speed and distance values based on the stride length. A message will also ap-
pear on the Track Plus Console when the Leg Sculptor Mode is started or exited.
Resistance Device
The Resistance device in the E5 cross-trainer is an Eddy-Current Brake. The resistance level is controlled through the
console and Activity Zone by sending signals to a small servo motor. The servo motor contains a Potentiometer that
tells the console the position of the brake magnets. The servo motor pulls a cable that is attached to magnets on the
actual Eddy-Current Brake. The movement of these magnet changes the resistance level felt by the user. The magnetic
fi eld in the brake and therefore the resistance felt by the user also increase with increased speed of the product.
Refer to Resistance Control in this section for an in depth explanation of the resistance system.
Electrical Stride Adjustment
The stride length of the product can be changed by selecting different stride lengths on the Activity Zone. The stride
length is controlled by a motor controller inside the E5. The system works by the actuators located in the adjustment
links fi nding a home position (there are limit switches at both the minimum and maximum travel lengths) and then run-
ning a fi xed set amount of time to reach the requested stride length. There are 6 LED indicators on the motor control
board. Four of these indicate the status of each of the 4 limit switches. One is used to display the closure of the reed
switch (product rpm). The fi nal LED is used to display when full power is present at the motor controller. The motor
controller has a switching power transformer. This means that both the 230 volt and 110 volt versions of the product
use the same motor control board and Activity Zone board. However, the product uses voltage specifi c actuators as
well as some other components (see the E5 Parts Manual for details).
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