Nautel NV30LT-N, Руководство по эксплуатации и техническому обслуживанию

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NV30LT-N OPERATIONS & MAINTENANCE MANUAL DESCRIPTION
VERSION 0.1 2015-03-01 PAGE 3.1.1
SECTION 3.1: DESCRIPTION
This section provides a high-level description of the transmitter’s key sections. The transmitter circuitry
is subdivided into four basic stages:
 Ac-Dc Power Stage
 Control/Monitor Stage - see page 3.1.3
 RF Drive Stage - see page 3.1.4
 RF Power Stage - see page 3.1.5
Refer to the functional block diagram, Figure 3.1.1 on page 3.1.11.
NV30LT-N Electrical Schematics
Some descriptions in this section refer to electrical schematics (SD-#s) . These are located in Section 4 of
the NV30LT-N Troubleshooting Manual.
Ac-Dc Power Stage
See electrical schematic Figures SD-1A/B/C SD-2 and SD-3. The ac-dc power stage provides power to
operate the low voltage power supplies, which generate the 40 to 48 V dc voltage that is converted to
the low level dc voltages (±15 V and +5 V) used throughout the transmitter. This voltage is also
conditioned to operate cooling fans in the RF power module, reject load assemblies and splitter
assembly. The ac-dc power stage also converts the ac power source to a positive dc voltage (PA volts)
for the transmitter's RF power amplifiers and exciter(s). The transmitter accepts a wide range of ac
input voltage options:
 3-phase, **175 - 265 V ac (208 V ac nominal)
 3-phase, **303 - 459 V ac (380 V ac nominal)
 1-phase, **175 - 265 V ac (240 V ac nominal)
NOTE
: ** - The NV30LT-N’s full ac input range is 90 - 265 V ac (or 156 - 459 V ac, as applicable), but RF
output power is limited when the voltage is less than 175 V ac (or 303 V ac, as applicable).
The ac-dc power stage comprises ac input terminal block TB1, power supply interface PWBs (A1, A17
and A33), low voltage power supply (LVPS) modules 1A (U2), 1B (U3, if purchased), and power supply
modules (U4 through U11 and U14 through U29), two for each of the 12 RF power modules. There are
three amber LED pilot lamps (DS1 through DS3), located in the bottom, rear of the cabinet, that indicate
the presence of each ac phase. Ac voltage is distributed from TB1 to TB2 (power rack 1) TB3 (power
rack 2) and TB4 (power rack 3).