System Description Chapter 2

10-kW UHF Transmitter with Chapter 2, System Description
Feedforward Driver
840A, Rev. 0 2-11
Note: The circuit breakers discussed
in Table 2-12 are on the AC
distribution panel of the 10-kW
amplifier and the high-voltage power
supply assembly. For the other
circuit breakers on the panel to
operate, the main AC and the control
circuit breakers must both be
switched on
.
Note: When the preceding command
is completed, the automatic turn-on
procedure will cycle the transmitter
through the command status and
corresponding operating status steps
from left to right on the front panel
LEDs. The Command Status indicator
shows that a command has been
given and the Operating Status
indicator shows that the command
has been carried out.
Table 2-12. 10-kW Amplifier Assembly Command Status Indicators
STATUS INDICATOR FUNCTION
Blower (DS8)
Indicates that the Blower On command
(Enable) has been given by the control
logic. The blower is controlled by the
filament power supply control board that
sends a low Enable command to the
isolation relay on the blower assembly. The
relay energizes and the closed contacts
apply 220 VAC to the blower contactor K1.
If the blower circuit breaker is turned on,
the 208/240 VAC 3 phase is applied to (A1)
the blower and the unit will operate.
Filament (DS9)
Indicates that the blower is on and that the
Filament On command (Enable) has been
given to the filament power supply
assembly. If the black heat has been
applied to the filament for at least 10
minutes, the Operate command activates
the ramp-up phase of the filament power
supply.
Bias (DS10)
Indicates that the filament voltage has been
at 5.2 volts for approximately 20 seconds
and the Bias On command (Enable) has
been given to the isolation relay (A3) on the
control and bias power supply assembly.
The relay energizes and, when the bias
circuit breaker is turned on, applies 220
VAC to the bias power supply board.
High Voltage (DS11)
Indicates that the bias voltage is on and the
High Voltage On command (Enable) has
been given to the isolation relay (A24)
in the high-voltage power supply assembly.
The relay energizes and applies +12 VDC to
the (A18) isolation relay and (K1) the
contactor control relay that control the