Group 19, Motor Controls
19-1-4 • Description SM 765, Sep ’06
sequence is not followed completely. (Request for drive,
must be made after closing the key switch).
Capacitor Charge:
The controllers can hold an electrical charge for several
seconds, due to the power capacitor bank. A discharge
resistance is built in the controller, which ensures capaci-
tor discharge to a safe voltage in about one minute, after
the key is switched off. If it is necessary to work on the
controller before that time, discharge the capacitors as
described below.
Discharging Controller Capacitors
It is necessary to discharge the capacitors before you work
on the controller. To discharge the capacitors, disconnect
the battery at the battery receptacle, connect a 200 ohm 10
watt resistor between the positive and negative input post
of the controller for 10 seconds.
Communications with CLARK Dash:
The traction controller communicates by CANBUS to
CLARK dash. The dash shows Battery State of charge,
Hourmeter and fault code if a fault occurs.
Microswitches:
The micro switches must have a contact resistance lower
than 0.1ohm and a leakage current lower than 100 micro
amps.
When full load is connected, the voltage between the key
switch contacts must be lower than 0.1 volt.
The micro switches send a voltage signal to the micropro-
cessor when a function is requested (for example: running
request) is made.
Accelerator Unit:
The accelerator unit consists of a potentiometer in 3 wire
configuration.
CPOT (C21) signal.
EN ACC (C8) is the accelerator enable. It is fed with
+Batt from the key switch.
NPOT (C20) is the accelerator negative supply. This out-
put is feed back to the microprocessor A/D converter to
test the continuity of the accelerator unit circuit (test of
pot wire disconnection). The procedure for automatic
potentiometer signal acquisition is carried out using the
handset. This enables adjustment of the minimum and
maximum useful signal level (PROGRAM VACC func-
tion), in either direction. This function is unique when it is
necessary to compensate for asymmetry with the mechan-
ical elements associated with the Potentiometer. Espe-
cially relating to minimum level. The sequence of
procedure is described later in this manual.
Analog control unit
Connection C25 (PTHERMR) and C24 (NTHERMR) are
used for the right motor thermal sensor. Connection C35
(PTHERML) and C34 (NTHERML) are used for the Left
motor thermal sensor. Sensors are analog.
Speed Feedback
The traction motors control is based upon the motor speed
feed back. The speed transducer is an incremental
encoder, with two phases shifted at 90°. The encoder is
supplied with +12V from the control panel.
Steer Angle Transducer
Angular position of steered wheels in transduced to an
electric information (voltage) by means of a potentiome-
ter, with following characteristics:
− Positive supply: 12V
± 2V
− Voltage potentiometer : 1V~9V
− Netural : 5V
− Potentiometer is installed in a way that in the
zero position (straight wheels), pot output volt-
age is in the middle of the electric range corre-
sponding to a full left-to-right transition of
steer wheels;
− The potentiometer is installed in a way that,
when the truck turns right, pot voltage
increases;
− Use "SET STEER MIN" and "SET STEER
MAX" functions of the handset to record the
extremes (minimum and maximum) of the
potentiometer range;
− Use "SET STEER 0-POS" function of the
handset to record the pot output when the steer
wheels are straight.
To Next Page
Loading...
