GE SX TRANSISTOR CONTROL IC3645SR4U404N2 Manuel D’Utilisation

TURN ANGLE POTENTIOMETER INSTALLATION 

SX TRANSISTOR CONTROL

 

 

 

Page 69

 

 

January 2000 

 
Section 8.1 GENERAL: 
 

The potentiometer used for the turn angle must be a 320 degree rotation device that is attached to the steer wheel in a manner to 

cause a 1:1 rotation ratio between the two devices.  Any ohm value potentiometer can be used, but it is suggested that it be at 

least 2K ohms or above, to keep the wattage of the potentiometer to a minimum.  The turn angle potentiometer provides a voltage 

divider circuit that allows the left and right motor controller to determine the turn angle of the rear steer wheel of the vehicle. 

The potentiometer is connected to the two controls as show in Figure 1. After the potentiometer is installed on the vehicle, it will 

need to be adjusted to insure proper operation of the vehicle.  

 
OPERATION: 
 

To insure proper operation, the input voltage at P12 on both the left and right 

controls must coincide with the turn angle of the steer wheel. When the steer 

wheel is straight ahead ( Zero Degree Turn Angle), the input voltage at each 

control should be 2.15 volts. As the vehicle turns left, this input voltage will 

decrease, as the vehicle turns right, the input voltage will increase. The graph 

in Figure 2 outlines the input voltages, the actions of the controls and the 

corresponding turn angles of the steer wheel. A complete listing of input 
voltages, steer angles and control actions can be found in Section 8.2 - 320 

Degree Potentiometer Input.  As an example of control operation as 

compared to the input voltage, the following series of events takes place in a 

left turn from the zero to the 90 degree steer wheel position. In the first 16 

o 

of 

travel (2.15 to 1.90 volts), there is  no change to the inside wheel speed. Between 16

o

 (1.90V) and 66

o 

(1.10V), the inside motor will 

reduce its speed proportionally from top speed at 16

o

 to creep speed at 66

o

. There will also be also available two vehicle speed 

limit enable points during the transition from 16

o

 to 66

o

. Speed limit 1 can be enabled at 41

o

 and speed limit 2 can be enabled at 

60

o

. Between 66

o

 and 71

o

, the inside wheel will be in a free wheel mode. As the steer reaches the 71

o

 point, the inside wheel can 

now be programmed to reverse and accelerate proportionally in the opposite direction. Above 86

o

 is over travel for the turn 

angle potentiometer. 

 
SETUP: 
Before any adjustments are done, jack up the drive wheels. 

Install the potentiometer on the vehicle steer wheel in such a way to allow adjustment of the shaft with the potentiometer and 

connected to both the left and right controls.  Setup of the turn angle pot can be done in several ways, detailed below. 

 
Volt Meter Method: 
Attach a volt meter, positive to P12 and negative to P8. Insure that the steer wheel is pointing straight ahead (Zero Degree 

Angle); connect the battery and adjust the potentiometer until the voltage between P12 and P8 is 2.15 volts. Lock down the 

potentiometer shaft and turn the vehicle all the way to the left turn stop, the voltage should be .93 volts or less. Turn the wheel to 

the right turn stop, the voltage should be 3.32 volts or greater. 

 
Handset Monitor Mode Method: 
Plug the Handset into the left motor controller. Insure that the steer wheel is pointing straight ahead (Zero Degree Angle) and 

connect the battery. Place the Handset into the monitor routine (Function 25) to view RAM location 95, which is turn angle volts, 

using the following steps: 

 

1.  Push CONT 10 

2.  Adjust Handset to 95 

3. Push 

STORE 

4.  Angle Value Displayed 
5.  ESC to 8888 ( To verify that you have the correct location ) 

6.  Push CONT 10 

7.  Display should read 95 

8. Push 

STORE 

9.  Angle Value Displayed 

P8

Section of Left Motor

Control (Master)

Section of Right Motor

Control (Slave)

P12

P9

P12

4.3V Suppl

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 Angl

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Suppl

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 N

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T

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 Angl

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Input

320 Degree

Potentiometer

Figure 1