16
MicroController Control System
System Operation
General Information
The MicroControl Panel is the control center and the
Logic Unit (logics) is the decision making part of the
MicroController System. The logics provide a self
contained Battery Discharge Indicator (BDI) with lift
interrupt and built-in diagnostic capabilities. The
battery charge state and Quick diagnostic are
monitored by the logics and displayed by the
Central Vehicle Monitoring System (CVMS) located
on the steer console.
NOTICE
Damage to all motors and control panels will
result. The motors and control panels are 48 volt
unit and must be operated at their designed
voltage. The voltage can not be changed
without changing motors and control panel.
The steering system is activated when the truck is
powered up and the line contactor closes. The truck
uses a combined power steering/hydraulic system
where the hydraulic fluid for steering is provided by a
DC series hydraulic motor, pump, and priority valve.
The traction motor and the hydraulic pump motor are
controlled by pulsing MOSFETS ON and OFF and
controlling contactor operation.
The speed and direction of the drive motor are
controlled by voltage inputs to and outputs from the
logics. Inputs to the logics are generated by the
accelerator control and direction switch. Outputs
from the logics control contactor coil and drive
MOSFET pulsing.
The drive circuit pulses MOSFET to provide travel
speed control up to 95% of full speed, after which the
bypass contactor close to provide full speed.
The drive circuit includes a failure protection circuit
which detects malfunctions of the drive power circuit,
a plugging circuit to provide electrical braking and a
current limit circuit to prevent excessively high
currents during MOSFET pulsing.
The speed of the hydraulic pump motor is controlled
by voltage and switch inputs to and outputs from the
logics. Outputs pulses the hydraulic pump MOSFET
The MOSFET pulse to control the speed of the
hydraulic pump motor. To provide full speed the
logics turns the MOSFET ON 100%. The hydraulic
pump system includes a failure protection circuit to
protect against malfunctions of the power circuit.
Thermal protection circuits are used on the
hydraulic pump motor, the drive motor and the
control panel to prevent permanent damage caused
by over heating.
Summary of Contents for B20S-3
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