Nautel NV7.5, Operation And Maintenance Manual

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NV10/NV7.5 Operations and Maintenance Manual Description
Issue 3.4 2016-08-03 Page 1-3
LVPS modules
See Figure
SD-1
(
A
,
B
or
C
). LVPS modules A (U3) and B (U4) convert the ac input voltage to
the regulated low voltage dc supplies. The +5 V, +15 V and -15 V regulated outputs of the
supplies are ORed together at the control/interface PWB (A1) and applied throughout the
transmitter.
+12 V power supply modules
See Figure
SD-1
(
A
,
B
or
C
). +12 V power supply modules A (U1) and B (U2) convert the ac
input voltage to the reg12 V dc supplies. The +12 V outputs are ORed together on the
power supply distribution PWB (A7) and a 12 V supply is applied to the control/
monitor stage.
Power supply distribution PWB
See Figures
SD-1
(
A
,
B
or
C
) and
SD-3
. The power supply distribution PWB (A7) interfaces
between fan power supply modules U7 and U8 and the cooling fans for RF power modules 1
through 4 and the reject load. The fan voltage (+48 V) is applied via power rectifiers CR1 and
CR2 to the transmitter's cooling fans. A nominal 47 V is applied as Fan V Sample A and B to
the control/monitor stage for metering and fan PS fault detection.
The power supply distribution PWB also interfaces between SBC/AUI power supplies U1 and
U2 and the control/monitor stage. +12 V is applied via power rectifiers CR3 and CR4 to the
control/monitor stage. A n12 V is applied as +12V Sample A and B to the control/
monitor stage for metering and supply fault detection.
Control/monitor stage
See electrical schematics
SD-4
and
SD-5
and Figure 1.1 on page 1-4 . The control/monitor stage
monitors critical samples and status/alarm signals from the ac-dc power stage, RF drive stage
and RF power stage. For example, RF power monitoring and RF power stage status
information is applied to the control/monitor stage. Based on the value and status of each
input, the control/monitor stage produces the appropriate control signals for the RF power
stage to ensure the proper operation and protection of the transmitter. The control/monitor
stage also provides the remote control/monitor interface for the transmitter.
The control/monitor stage comprises a control/interface PWB (A1), a remote interface PWB
(A2), an LCD touch monitor (U5) and a single-board computer (U6).