Honeywell Chadwick-Helmuth 8500C, Руководство по обслуживанию

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Detailed Description
8500C/8500C+ System Maintenance Manual 4-11
a. Velocimeter Inputs. Twelve discrete Velocimeter connectors are mounted on the front
panel of the 8520C. All inputs may be simultaneously connected to twelve transducers
(Velocimeters). Each connector provides reg12 and -12 VDC power to a
connected Velocimeter.
b. Azimuth Pickup Inputs. Four discrete azimuth pickup connectors are mounted on the front
panel of the 8520C. All pickup inputs may be simultaneously connected to four pickups,
which may be any combination of magnetic or photocell types.
c. 12:4 Crosspoint Switch. The microcontroller in the controller board controls vibration
transducer switching with a 12:4 crosspoint switch array. Crosstalk between channels is
better than -80 dB from DC to 10 kHz.
d. Dual Sum/Difference Function Blocks. Two sum/difference function blocks derive both
the sums and differences of their two inputs. The four inputs to these circuits come from
the outputs of the crosspoint switch array. Each sum circuit implements (A+B)/2, which
allows measurement of the scaled sum of two distinct channels or, when the same, a single
channel. Similarly, the difference circuits implement (A-B)/2, which allows measurement
of the scaled difference between two distinct channels or, when channels A and B are the
same, a single channel.
e. 2:1 Multiplexers. The microcontroller controls electronic switches in the second 2:1
multiplexer, which selects either the sum or difference output of the first sum/difference
function block for buffering and routing to a peak detect and hold circuit.
Figure 4-6. Controller Board and Quad Peak Detector Board Block Diagram
PICKUP INPUT 1
PICKUP INPUT 2
PICKUP INPUT 3
PICKUP INPUT 4
4:1 MULTIPLEXER
4:1 MULTIPLEXER
PICKUP SIGNAL
TO 8500
DIGITAL BOARD
2 CHANNELS
2 CHANNELS
A-B FUNCTION BLOCK
A+B FUNCTION BLOCK
A+B FUNCTION BLOCK
A-B FUNCTION BLOCK
2:1 MULTIPLEXER
2:1 MULTIPLEXER
PEAK DETECT AND HOLD
ANALOG-TO-DIGITAL
CONVERTER
SERIAL
COMMUNCIATIONS
TO/FROM 8500
DIGITAL BOARD
63A03A
MICROCONTROLLER
+ 12 VDC
LATCH
POWER SWITCH
POWER
MONITOR
SHORT
CIRCUIT
LAMP
VELOCIMETER BIT
PULSE DETECTOR
FILE: FIG4-6A.DRW
12:4
CROSSPOINT
SWITCH
TO 8500
ANALOG BOARD
PULSE DETECTOR
PULSE DETECTOR
PULSE DETECTOR
VELOCIMETER INPUT 1
VELOCIMETER INPUT 2
VELOCIMETER INPUT 3
VELOCIMETER INPUT 4
VELOCIMETER INPUT 5
VELOCIMETER INPUT 6
VELOCIMETER INPUT 7
VELOCIMETER INPUT 8
VELOCIMETER INPUT 9
VELOCIMETER INPUT 10
VELOCIMETER INPUT 11
VELOCIMETER INPUT 12
QUAD PEAK DETECTOR BOARD A3