Platinum Z5 CD, Руководство пользователя

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WARNING: Disconnect primary power prior to servicing.
Overall System Theory
e. FAILSAFE. Discussed earlier.
f.
PA_15V_FAIL. This fault comes from both of the PA Controller Boards. It is
triggered when there is a loss of the -15V on BOTH of the PA Controllers. If
the -15V supply is lost, the PA Controllers will not be able to mute the PAs
and therefore cannot protect them, so the exciter and IPA will be muted to
protect the PAs.
g. CONTACTOR_ON(BAR). Discussed earlier.
4.7.6.1.5 Exciter Select
Exciter Select is only applicable if the transmitter is configured with Main/Alternate
exciters. Exciter select is software controlled by the Master Controller. It can be
switched manually or will switch automatically if the active exciter fails (no RF
output). Exciter switching is done by latching relay K1. EXCITER1_SELECT is a
pulsed signal which will go high to select exciter 1. This will make U12-8 high if
the Master Controller is working (MSTR_NORMAL 1 will be high). This passes
through inverter U13-16 and resets K1. This places K1 in the position shown on the
schematic. K1-4 will be pulled low. This is sent two places:
a. The low from K1-4 goes off the board to the IPA Backplane Board where it
actuates the exciter select relay K1 to the position shown on the schematic. It
also goes to the Master Controller as a status signal, so it knows which exciter
is physically selected.
b. The signal from K1-4 is also used to mute the off air exciter when in the Life
Support Mode, via U35-3 and U35-6, which tie into the exciter mute lines.
Exciter 2 is selected when EXCITER2_SELECT goes high which will SET K1. K1-
4 will go high and this will switch K1 on the IPA Backplane board to the exciter 2
position.