Precor AMT12 base, Service Manual

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the generator. The zero crossing counts the speed of the generator and the LPCA processor
divides out the step-up in the pulleys will determine the RPM at the cranks.
When the user begins to pedal the unit, The LPCA powers up right away. To insure that all regulated
supplies are up and stable, the unit holds power off of the UPCA until a minimum of 20 RPMs at
the crank is detected. Once this minimum speed is detected, the processor will turn on a relay,
which in turn switches power onto the UPCA. When the us
er presses “Quickstart” or goes into a
program, the UPCA is going to want to use the actual stride count for its user display functions.
The stride is counted by the LPCA processor, and transferred to the UPCA processor via the
communication cable.
DC Lift System
– Motion Control (If Equipped)
The motor used in the lift system of a self-powered unit is a DC motor. It is powered by 12VDC
from the battery, and utilizes a 7 amp self-resetting fuse on the lower control module to protect the
switching circuitry on the lower control module. Motion can be driven in 2 different directions by
switching the polarity of the battery voltage applied to the windings of the motor. Since the lift motor
is only expected to travel at one speed, the voltage is NOT varied. A single voltage is switched to
the lift motor to initiate motion, and the polarity is switched to control direction.