9/15/06
888-2586-001
4-59
WARNING: Disconnect primary power prior to servicing.
Section 4 Overall System Theory
Platinum Z16HD+
initial 100mSec turn on pulse from U4-10 is gone, the CLR input to U4 will also
go low, holding the Q output low whether the ON button is pressed or not. This
prevents U8-10 from generating a 3 second mute command for no reason, since
the Master Controller is not working and cannot be initialized (if the Master was
working, MSTR-NORMAL 1 at U33-13 would be high removing the clear from
U4-13). The transmitter must first be turned off, then turned back on to try to ini-
tialize the system. Once the transmitter is turned off, a turn on pulse can be gener-
ated since K4-4 will be high when the contactor is disengaged. This removes the
clear from U4 allowing the transmitter to turn on. In summary, the signal at U33-
12, CONTACTOR_ON(BAR), will not allow a second turn on pulse to be deliv-
ered while the transmitter is still running and in Life Support Mode.
b.
The CONTACTOR_ON(BAR) signal at U30-12 is used to disable the power sup-
ply when the contactor is turned off. The signal is high when the transmitter is off
and low when turned on. The other input, U30-13 comes from the Master Con-
troller, SUPPLY_DISABLE, which will pass through to U6-8 as long as the Mas-
ter Controller is operating normally. When the PS DISABLE signal at U30-11
goes high, the power supplies will be shut off via the PS Controller.
c.
U30-10 ties the CONTACTOR_ON(BAR) signal into the SYSTEM-MUTE line,
which will mute the exciter and IPA when the contactor is off.
Remote Low Power ON Command
This command should only be used during Life Support Mode and is therefore
discussed later.
4.8.7.1.2 Transmitter Turn OFF
Whenever the OFF button on the front panel is pressed, the Master Controller sends a
high TX-OFF command to J1-A53 on the Life Support Board. This is tied to AND gate
U25-12. When the Master Controller is working, MSTR_NORMAL1 at U25-13 will be
high and U25-11 will go high. This high will pass through to U31-11, U33-6 and
inverted at U16-10 before reaching the RESET input of K4. When K4 is RESET, the
AC mains contactor will de-energize, shutting off the transmitter. The
CONTACTOR_ON(BAR) signal at K4-4 will go high, applying a SUPPLY_DISABLE
at U30-11 to shut off the power supplies and a SYSTEM_MUTE via U30-10 which will
mute any exciters and IPAs.
Remote Transmitter Turn OFF
REM_OFF(BAR) is activated via the remote control interface. When the remote control
pulls this line low, it will activate optical isolator, U23, bringing U23-6 low. This is
inverted at U27-6 and applied to U25-10 as an active high signal. The input at U25-9 is
not used and will always be high. Therefore the AND gate output at U25-8 will follow
Summary of Contents for Platinum Z16HD+
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