UHF Analog Driver/Transmitter/
Chapter 4, Circuit Descriptions
Translator
LX Series, Rev. 3
4-22
terminations, used as dissipation loads,
connect to the reject and reflected ports,
J5 and J4, of the coupler.
4.6.6 (A5) Amplifier Control Board
(1303682 or 1301962; Appendix B)
The amplifier control board provides LED
fault and enable indications on the front
panel of the module and also performs
the following functions: overdrive
cutback, when the drive level reaches the
amount needed to attain 110% output
power; and overtemperature, VSWR, and
overdrive faults. The board provides
connections to the LCD Display for
monitoring the % Reflected Power, %
Output Power, and the power supply
voltage.
If the Module OK LED, located on the
front panel, is Red and blinking, a fault is
present. The meaning of the blinking
LED is as follows.
1 Blink:
Indicates Amplifier Current
Fault.
2 Blinks:
Indicate Temperature Fault.
3 Blinks:
In32V Power Supply
Over Voltage Fault.
4 Blinks:
In32V Power Supply
Under Voltage Fault.
5 Blinks:
Indicate Reflected Power Fault.
6 Blinks:
In12V or –12V Power
Supply Fault
4.6.6.1 Schematic Page 1
U4, located upper center of page, is an in
circuit microcontroller. The controller is
operated at the frequency of 3.6864 MHz
using crystal Y1. Programming of this
device is performed through the serial
programming port J2. U4 selects the
desired analog channel of U1 through the
settings of PA0-PA3. The outputs of Port
A must be set and not changed during an
analog input read of channels PA5-PA7.
PA4 of U4 is a processor operating LED
that monitors the ±12 VDC. PA5 is used
to monitor the +12VDC supply to the
board. PA6 is the selected channel of
analog switch U1. PA7 is connected to a
via, V10, for future access.
U6 is a serial to RS-485 driver IC. U7 is a
watchdog IC used to hold the
microprocessor in reset, if the supply
voltage is less than 4.21 VDC. U7
momentarily resets the microcontroller if
Pin 6 (!ST) is not clocked every second. A
manual reset switch is provided but should
not be needed.
In the Upper left corner, U3 is used to
determine where the amplifier control
board is located. The eight inputs come
from the main amp connector and are used
to set the SCADA address of the controller.
Pull-up resistors set a default condition of
logic high.
U5 below U3 is used for getting digital
input information of the board. Page two
has several monitoring circuits that provide
information on the amplifier’s status. Many
of these circuits automatically shut down
the amplifier if a specific fault occurs.
U8 below U5 is used to control four board
mounted status LEDs. A FET is turned On
to shunt current away from the LED to turn
it Off. U9 below U8 is used to enable
different features within the software.
Actual use is to be determined.
4.6.6.2 Schematic Page 2
In the lower right corner are voltage
regulator circuits. U22 should allow for
0.14 amps of power using its 92 C/W
rating if Ta = 60°C max and Tj = 125°C
max 0.26 amps can be obtained from U22
if the mounting pad is 0.5 square inches.
The controller will not need this much
current. U23 and U24 are low drop out +5
VDC, voltage regulators with a tolerance
greater than or equal to 1%. 100mA of
current is available from each device but
again the controller will not need this much
current.
In the upper left section are circuits with
U12 and U13. U12 is used to generate a
regulated voltage that is about 5 volts less
than the +32 VDC supply, approximately
+26.25 VDC. When the +32 VDC supply is
enabled, the circuitry around U13B is used
Содержание INNOVATOR
Страница 99: ...APPENDIX A LX SERIES ANALOG SYSTEM SPECIFICATIONS...
Страница 102: ...APPENDIX B DRAWINGS AND PARTS LISTS...
Страница 105: ...APPENDIX C TRANSMITTER LOG SHEET...