Figure 4-7.–Radar azimuth converter functional block diagram.
CHANNEL 2 DATA SOURCE SELECT switch in
The DRAC is similar to the SRAC except the
the BACKUP position. Display channels 3 and 4 are
tied together in the same way.
SENSOR CONVERTER GROUP (SCG)
The sensor converter group (SCG) of the CEG is
the main interface between the system radars and the
display consoles. The SCG consists of three synchro
radar azimuth converters (SRACs) or two SRACs and
one digital radar azimuth converter (DRAC), located
in one drawer of the CEG.
Each SRAC or DRAC provides the interface for
one radar. The SRAC receives azimuth data and
triggers from a synchro radar and generates the
signals required to display sweep and range marks on
the display console. The DRAC performs the same
function with signals from a digital radar. The SRAC
consists of four fictional areas as shown in figure
synchro-to-digital converter is replaced with the input
functional area.
Synchro-to-Digital Converter Function
The synchro-to-digital converter receives 60-Hz or
400-Hz synchro azimuth data from the radar and
converts it to a 12-bit digital value that is sent to the
polar-to-Cartesian converter.
INPUT FUNCTION.– The input function, used
only in the DRAC, receives digital azimuth data from
a digital radar and converts it to TTL levels. The
azimuth data consists of 11 bits representing the
absolute value of sin q/ cos q and 1 bit representing the
sign. The input function retransmits the azimuth data
received back to the radar for error checking.
CONTROL,
T I M I N G , A N D
TEST
4-7. These fictional areas are:
synchro-to-digital converter
control, timing, and test circuits
polar-to-Cartesian converter
digital transmitter
FUNCTION.– The control, timing, and test fiction
produces the signals that control the operation of the
polar-to-Cartesian conversions, provides the system
clocks for the converter, and produces digital test
azimuth for the self-test functions.
POLAR-TO-CARTESIAN
CONVERTER
FUNCTION.– The polar-to-Cartesian converter
function converts the parallel azimuth data from the
synchro-to-digital converter to DC and DU pulse
trains and sign of DC/ sign of DU. The 10 LSBs of the
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