GE SX TRANSISTOR CONTROL IC3645SR4U404N2 Manuel D’Utilisation

Page de 74
BASIC OPERATION AND FEATURES 
SX TRANSISTOR CONTROL
 
 
 
Page 7
 
 
January 2000 
to optimize motor and control performance, and this setting 
will be determined by GE and OEM engineers at the time of 
vehicle development.  This setting must not be changed by 
field personnel, without the permission of the OEM. 
 
Section 2.1.4.b Speed Limits 
 
This feature provides a means to control speed by limiting 
motor volts utilizing three "adjustable speed limits.  This 
motor volt limit regulates top speed of the transistor 
controller, but actual truck speed will vary at any set point 
depending on the loading of the vehicle. Each speed limit 
can be adjustable with the Handset using Functions 11, 12, 
and 13. 
 
Section 2.1.4.c Proportional Operation for Dual Motor 
Vehicles 
 
A key performance advantage of this control is the ability to 
achieve actual "proportioning" of motor speed. In a 
non-proportioning, or single control, system when the 
vehicle starts to turn, the outside drive wheel turns in a 
larger circle than the inside wheel. Depending on the 
geometry of the vehicle, at some degree of turn angle, the 
inside wheel must slow down to prevent scrubbing of the 
wheel. This is accomplished on single control system by 
disconnecting the inside motor and letting the wheel "free 
wheel" or "float" at whatever speed is dictated by the 
outside wheel that is still under power. The main 
disadvantage of this system is that no torque is available on 
that motor when the inside wheel is in the "free-wheel" 
mode, and performance in a turn is reduced. When the 
steer wheel nears to the 90° turn angle, the inside motor is 
re-connected in the opposite direction of the outside. At 
this point, torque is returned to the inside wheel and the 
speed is the same on both motors. 
 
With two controls, the speed of each motor can be 
regulated independently. The driver controls the speed of 
the outside wheel with the accelerator input signal. The 
inside wheel speed is controlled by the turn angle of the 
steer wheel . A potentiometer is attached to the steer wheel 
in order to communicate the steer angle to the controllers. 
During vehicle manufacture, software selection identifies 
each control for its application as a right or left control. 
The controls are physically identical, and it is only software 
that separates a right from a left control or differentiates a 
control for a dual motor application from one intended for a 
single motor vehicle. As the steer reaches some 
pre-selected turn angle, approximately 20
o
, the speed of the 
inside wheel decrease proportionally to the speed of the 
outside wheel. This proportional decline will continue on a 
linear path until the steer angle reaches another pre-
determine angle of, approximately 65
o
 
At this point, the inside wheel will stop, as the steer angle is 
increased toward the 90° point, the inside wheel will 
reverse direction and start to accelerate proportionally in 
speed. As the steer angle reaches the 90° point, the inside 
wheel speed will be the same as that of the outside wheel. 
During this entire turn, except for several degrees when the 
motor was stopped to change direction, torque was always 
present on the inside wheel, providing a smoother ride 
throughout the turning radius of the vehicle. 
 
Details for adjustment of the steer angle potentiometer can 
be found in Appendix A of this manual. 
 
0
O
10
O
10
O
20
O
20
O
30
O
30
O
40
O
40
O
50
O
50
O
60
O
60
O
70
O
70
O
80
O
80
O
90
O
100%
50%
50%
100%
90
O
100%
50%
50%
100%
RIGHT
MOTOR
LEFT
MOTOR
STEERING ANGLE
LEFT
TURN
RIGHT
TURN
LEFT
MOTOR
RIGHT
MOTOR
RIGHT
CONTROL
LEFT
CONTROL
0
O
90
O
90
O
REV - SPEED - FWD
REV - SPEED - FWD
 
Section 2.1.5  Ramp Operation 
 
Section 2.1.5a Ramp Start 
 
This feature provides maximum control torque to restart a 
vehicle on an incline. The memory for this function is the 
directional switch. When stopping on an incline, the 
directional switch must be left in its original or neutral 
position to allow the control to initiate full power when 
restarted. The accelerator potentiometer input will 
modulate ramp start current. 
 
Section 2.1.5b Anti-Rollback 
 
This feature provides retarding torque to limit rollback 
speed in the non-travel direction when the ACC pedal is  
released when stopping on a grade, or when the brake 
pedal is released when starting on a grade. This feature 
forces the vehicle to roll very slowly down the grade when 
accelerator or brake is released. Because the vehicle can 
gain significant speed during roll-back, the torque needed 
to re-start on the ramp is lower than an unrestricted roll-
back speed. 
  
Section 2.1.6 Steer Pump Contactor Time Delay 
 
This feature provides two options for SP time delay. Option 
1 provides a 0.5 to 63 second time delayed drop out of the 
steer pump contactor when the Forward or Reverse 
directional switch is opened. This Option 1 is overridden by 
a 1.5 second time delayed drop out whenever the seat 
switch is opened. Option 2 provides a 0.5 to 63 second time 
delayed drop out of the SP contactor when the seat switch 
is opened.