Technogym BIOSTRENGTH LINE, Service Maintenance Manual

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BIOSTRENGTH LINE: Service & Maintenance manual - rev. 2.1
Page 3.18
3.4. SEAT MOTOR MANAGEMENT
3.4.1. M
ECHANICS
On a few machines, the position of the seat on the machine may be adjusted (not present on
Abdominal Crunch and Lower Back). On some machines this is done by adjusting the horizontal
position (Leg Extension and Leg Curl), while on others it is vertical (Vertical Traction, Shoulder
Press, Chest Press and Rowing Torso). On Leg Press, the motor and control electronics are
different, and will thus be discussed in paragraph 3.5. “Seat motor management for Leg Press”.
Regardless of the machine, the position is adjusted by using a mechanism such as the one
schematically illustrated in the figure below.
Figure 3.4.1
To adjust the seat, a linear actuator a , while its internal motor moves, moves the stem b forward and
back until the front limit c and rear limit d are reached. The actuator a is fastened to the machine
frame e by means of the fitting f , while the stem b is fasted to the seat g : thus moving the stem
forward and back also moves the seat.
3.4.2. C
ONTROLS
To adjust the seat position, the CPU board sends the motor up signal (to move the seat forwards or
back) or the motor down signal (to move the seat up and down) to the Bio servo board. This powers
the motor properly, which in turn moves. Due to the movement of the motor, the reed sensor
produces the pulses that the Bio servo board sends to the CPU board. The CPU board counts the
pulses received. As soon as the number of pulses corresponds to the desired position, it disables the
motor command signal.
If the current absorbed by the motor after the starting point is too high, and above a set threshold
value, the Bio servo board sends an alarm signal to the CPU board to disable the motor. The pre-set
value may be adjusted using trimmer PT2.