Harris DiamondCD Series, Техническое руководство

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3/6/08 888-2463-001 4-23
WARNING: Disconnect primary power prior to servicing.
Section 4 Theory of Operation
Diamond Series™
4.7.2.14 Analog Voltage Reference
The reference voltage for the DAC on this board need an accurate voltage reference
which is regulated by U13. Using a precision volt meter on TP 50, adjust R97 for 4.999
VDC to 5.003 VDC.
4.7.3 32VDC Power Supplies
The 32 volt PA Module power supplies are vendor manufactured power supplies put
into a slide-in chassis with a breaker. Refer to the vendor for service documentation.
4.7.4 Low Voltage Power Supplies
The Low Voltage power supplies are vender manufactured power supplies. Refer to the
vender for service documentation.
4.8 Power Amplifier Module
The Power Amplifier Module consists of the following sub-assemblies; Module
Controller, input Phase and Gain board, RF Driver Pallet and 6 RF Pallets, Pallet
splitter and combiner. The module comes factory adjusted.
4.8.1 Module Controller
The function of the Module Controller board is to provide a means of PA Module
protection and compensation as well as interfacing to the Main Controller via CAN bus
and an RS485 port which can be used as a bench test or for a back up communications
bus. The Module controller in each PA module will control that amplifier’s basic
operation and gain over frequency compensation. It monitors and protects the amplifier
in failure mode. The micro-processor based module controller makes operational
decisions based on input from the module and the serial data bus. It provides a safe
sequence to turn the module ON and OFF, provides reference voltage to the Phase and
Gain board which forms an AGC closed loop system. It also reports all of the module’s
data and status to the Main Controller in the Control Cabinet, with a data update rate of
less than one second.
The Module Controller makes the Power Amplifier module self protective by
monitoring the module’s working condition, such as heat sink temperature, input RF
power, output RF power, PA pallet currents and Power Supply DC voltage. It turns the
module OFF if it senses a critical failure and sends a message to the Main Controller
and specifies the critical path. If the failure condition is not critical, the module will