Motor Control CCA A2 Test Point Signals
A1 high test
A low test
B low test
B1 high test
A2 high test
B2 high test
As shown in figure FO-4, input A1 is applied through driver Q5 to
voltage regulator U1. Voltage regulator U1 provides a constant
current source to current amplifiers Q6 and Q1. The resulting A1
high output is routed to the windings of stepper motor M1 and to
extender CCA A5. Diode CR2 prevents excessive current surges to the
motor windings and provides a MOTOR FLYBACK output to extender CCA
assembly contains four rotary switch wafers and eight RF CCAS.
Stepper motor M1 operates the switch wafers to select one of 20 tuned
circuits through the CCAs. As shown in figure FO-5, RF relays K1 and
K2 receive TX/RX inputs and control the RF path through the RF switch
assembly. For the transmit mode, relays K1 and K2 operate. Relay K1
applies the RF input from connector J2 to the selected tuned circuit.
Relay K2 applies the tuned circuit output through connector J1 to the
energized and the RF switch assembly is bypassed.
Refer to figure FO-1. The feedback
3-5.5 Feedback Switch CCA S4.
switch CCA receives Band 0 through Band 24 signals from control logic
CCA A3 that specifies the transmit mode operating frequency. The
feedback switch CCA is operated by stepper motor M1, and provides an
SW FDBK output to control logic CCA A3 when the stepper motor reaches
the proper position.
The tunable coupler status circuit receives antenna-deployed
switch and DF input signals at connector pins J3-A through J3-D. The
signals are combined with status signals from the tunable coupler
CCAS and applied to external equipment in the system.