PAT DS 150, Service Manual

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Mechanical Description Of The System 2
2 MECHANICAL AND ELECTRICAL DESCRIPTION OF THE CENTRAL UNIT
All the data of the crane is stored inside the central unit in EPROM‟s. The central unit receives all
actual information of the crane. This is computed against the reference data and the crane status is
continuously monitored.
Description of the Housing: The central unit DS150 is a rugged, waterproof sheet steel housing. It is
mounted on the left side of the turn table weldment or on the counterweight. The cables are led into
the central unit via strain reliefs and connected with fast-ons. An override switch is mounted on the
housing, which overrides the LMI function. The system is protected by a 2-AMP fuse, which is
mounted on the lower right side. The output signal is protected by a 10-AMP fuse, mounted on the
lower mid.
Description of the Boards: Inside the central unit (CU) there is a main board. The main board and
CPU is the heart of the system, and it contains the processor and the system and data EPROMs. The
system EPROM holds the operating system and data EPROM hold the crane and calibration
information. The wires from the various components are connected with fast-ons to the main board.
The main board holds the electronics necessary to receive, evaluate, and direct the continuous flow of
data from the sensors to the processor.
Main board components:
Power supply: Provides all the necessary voltages for the transducers and the electronics on the main
board.
Analog input part: Receives and prepares all the signals from the transducers for further processing.
Relays, an overload and anti-two-block relay: Controls the Bosch relay for lever lockout.
Incoming Signals: Signals from the transducers are connected to the main board. The signals vary
depending on the sensor:
Angle transducer signal is between -1.875V and -3.125V.
Length transducer signal is between -0.500V and -4.500V.
Pressure transducer signals are between 0.00V and -1.00V. (measured between the negative and
positive outputs)
Anti-two-block switch resistance is 4.7Kohms.
Digital inputs for the duty selection switches are on or off.
Outgoing Signal: The outgoing signal of the main board is the signal for lever lockout of connection
#48. In normal working conditions there are 12 volts at this connection. If there is an overload or anti-
two-block condition the signal becomes 0 volts. Furthermore, all voltages for the transducers are going
out through the main board.