AR 350AH1A, Руководство по эксплуатации и обслуживанию

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Model 350AH1A
28 Rev B
3.4 CONTROL CIRCUITS
3.4.1 Power On/Operate Circuits
This section describes the functioning of the switches, relays and controls in the AC/DC power distribution
system. See Schematic Drawing Number 10024922, Interconnect Diagram, 350AH1A .
Circuit breaker CB1 disconnects all circuits from the AC mains. Assume that circuit breaker CB1 is closed.
+5VDC and +/-15VDC are connected to the DCP and ALC board.
If the Keylock Switch is in the LOCAL position, when the POWER switch is energized, then +15VDC will
be applied to the Power On relay, K1. Note that in order to complete the circuit through K1, the external AC
interlock circuit must be closed. The rear panel Safety Interlock connector provides pins 10 and 14 for this
purpose. Another interlock circuit, provided in the same connector, is used for RF inhibit, pins 1 and 8, if the
user so desires. Both types can be used simultaneously in their respective circuits. If the AC interlock circuit
is open, a direct logic signal will be applied to the Control Panel to display ACINT on the display when
Power On is attempted. If the Inhibit interlock is open, INT will be displayed.
The energized relay K1 will apply the AC mains to the main power supplies. The amplifier will then be in the
STANDBY condition. In this state, all high level RF stages are without DC power, making it impossible to
produce any RF power in the amplifier. Cooling fans will be heard even though no DC is output from the
main power supplies. The main power supplies will be armed for DC Enable and waiting for Operate mode to
be executed.
If the RF ON button is pressed, and there are no interlock faults existing, the power supply inhibit signal is
removed, allowing high level amplifiers to become functional. After a short delay for circuit stabilization, all
Fault signals are monitored; if there are no faults then the amplifier will continue to function normally.
If the Keylock Switch is in the REMOTE position, the Power and RF ON functions are the same except that
they can only be performed remotely (i.e., from the user’s computer), since the front panel controls are locked
out when the amplifier is in the Remote mode.
3.4.2 A13 ALC Board (Schematic #10023927)
This section describes the operation of the level control board. The level control board performs the
following functions:
• Provides automatic level control of the amplifier’s output when the amplifier is placed in the ALC mode.
•
Limits RF input level to the amplifier when forward or reflected power levels exceed specified levels.
•
Drives forward and reflected indicators on the front panel display.