Axcera CHV400BTD, Technical Manual, Page: 63 / 87

Innovator CHV400BTD ATSC Transmitter Board Descriptions
Technical Manual, Rev. 0 59
(A8) Control Card, Innovator CX (1312543 )
The Innovator CX control board provides the overall system control for the CXB system.
There are two main elements of the board, U7 and U9. U7 is a programmable logic
device that is loaded with firmware, which provides the overall system control. It
decides whether or not to allow the system to generate RF output power, and turns the
+32 VDC power supply on and off depending on whether or not it is receiving any faults,
either faults generated on board, or faults generated externally. The second major
component of the board is the microcontroller U9, which controls the front panel
indications and drives the display. The U9 microcontroller is not involved in the decision
making process, U7 does that. Rather, it is layered on top of U7 and is the EPLD's
interface to the outside world. Information is passed between the microcontroller and
the EPLD. The microcontroller communicates information to and from the front panel
and sends the EPLD the information it needs to decide whether or not to allow the
system to turn on. The front panel viewable LEDs DS3 for Operate/Standby and DS4 for
Status indicate the current operating condition of the system are mounted on and
controlled by this board. The U9 microcontroller can also communicate, using the
Optional Ethernet Kit, with a daughter card that allows the user to view remote control
parameters via a web Ethernet interface.
The ±12 VDC and +5 VDC from the (A9) power supply are routed to the other boards in
the tray through this board. The (A10) +28/+42 VDC power supply connects the
+28/+42 VDC to the board at J19-1 with 4 common. The ±12 VDC and +5 VDC input
voltages to this board is connected through J21 and filtered before being connected to
the rest of the board. +12 VDC connects through J21-1, +5VDC through J21-2 & 3, and
-12 VDC through J21-6. Common connections for the input voltages are connected to
J21-4 & 5. The ±12 VDC and +5 VDC are used on this board and also routed to the
other boards in the tray through this board. The +3.3 VDC for the microcontroller and
programmable logic array, mounted on the board, is provided by the voltage regulator
IC U6 from the fi5 VDC input. The output of U6 can be adjusted to +3.3 VDC
using R120.
(A9 & A10) Power Supplies used in CHV20B, CHV200B, and Driver for CHV400B
& higher power
Voltages for the operation of the boards in the tray are generated by (A9) a +5VDC and
±12VDC power supply and (A10) a +28/+42VDC power supply. The 230VAC input to
the tray connects through the AC power cord at J10, the power entry module located on
the rear panel of the tray.
An On/Off 10A/250VAC circuit breaker is part of the power entry module. With the
circuit breaker switched On, the (L) line input is wired to F1 a 10 Amp fuse for over
current protection. The AC lines are connected to terminal block TB1, which distributes
the AC to (A9 and A10) the two DC power supplies. There are two varistors, mounted
on TB1, connected from the line input to neutral and to ground for surge protection.
The AC also connects to the (A11) fan mounted on the rear panel of the driver trays, but
in the CHV20B system the fan is connected through the A10 power supply. In trays
other than the CHV20B, the fan will run when AC is applied to the tray and the circuit
breaker is switched On. The +5VDC and ±12VDC outputs of the (A9) power supply
connects to the terminal block (TB2) that distributes the DC to the boards in the tray.
Some of the +5VDC and ±12VDC outputs connect directly to the 8 VSB Demodulator
and 8 VSB Modulator boards while the other outputs connect through the CX Control