Broadcast Electronics AM-2.5E, Руководство пользователя, Страница: 72 / 320

4-9
4-39.
METERING.
4-40. The transmitter metering consists of the forward power meter, reflected power/primary ac
input voltage meter, and the exciter modulation meter. Forward power information is
presented on the forward power meter. Reflected power/primary ac input voltage
information is presented on the reflected power/primary ac input voltage meter. The
meters are controlled by three-position switches. Forward and reflected power samples
for the metering circuitry are provided by the directional coupler circuit board. An ac
sample for the reflected power/primary ac input voltage meter is provided by an ac sample
circuit board.
4-41. Monitoring of exciter operations is provided by the exciter modulation monitor. Two 30
segment multi-color bar graph displays present L/L+R and R/L-R information. A X10
mode allows the monitoring of low level signals such as the pilot tone.
4-42.
COOLING FANS.
4-43. The AM-2.5E/AM-5E transmitters are equipped with 2 cooling fans. The fans are
controlled by an optically-coupled-relay. In the fans provide 500 CFM of cooling air for
the transmitter. A temperature sensor circuit board monitors the transmitter air
temperature and provides status information to the controller.
4-44.
INTERFACE CIRCUIT BOARD (AM-5E ONLY).
4-45. On AM-5E models, communication between the controller, RF power modules, and the
power supply circuit boards is provided by an interface circuit board. The circuit board:
1) routes status information from the RF power modules and power supply circuit boards
to the controller and 2) routes control signals from the controller to the RF power modules
and the power supply circuit boards.
4-46.
DETAILED DESCRIPTION.
4-47.
POWER SUPPLIES.
4-48. The AM-2.5E/AM-5E transmitters require a 196V to 252V ac single phase power source
(refer to Figure 4-3). The following text presents ac power source required for each
transmitter.
TRANSMITTER AC POWER SOURCE
AM-2.5E 196V to 252V ac 50/60 Hz single phase at 75 Amperes.
AM-5E 196V to 252V ac 50/60 Hz single phase at 125 Amperes.
4-49.
AC INPUT CIRCUITRY.
4-50. When the transmitter fused disconnect is closed, single phase ac power is routed through
an RFI filter to rear-door ac input switch S1. The filter prevents the coupling of RFI
components into or out-of the transmitter. S1 is the transmitter primary ac power safety
device. S1 disconnects primary ac power when the transmitter rear door is opened.
4-51. The ac line is monitored for high/low conditions by an ac line voltage monitor. The
monitor controls ac power contactor K2. The transmitter primary ac power will be
interrupted if the ac line is above 260 volts or below 190 volts. Overload protection for the
transmitter is provided by fuses F1 and F2.