Specifications

Section-4 Theory
November 11, 2013
4‐10
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4.4.4.5 CustomerI/OCard
TheprimaryfunctionoftheCustomerI/OCardistointerfacebetweentheinternaltransmittercontrolsystemand
allexternalorperipheraldevices.ThecustomerI/OcardislocatedintheTCUandisconnectedtotheCustomerI/O
boardconnectorsJ13andJ14insidethecabinettop.Formoredetailon
thecustomerI/Oconnectionswhichcanbe
foundonthecustomerI/Oboardon thetopofthecabinetrefertosection
4.5onpage4‐18andtosections2.11on
page2‐20and2.18onpage2‐33.
4.4.4.6 ExciterSwitcherCard
TheexciterswitchercardinthemaincabinetTCUcontrolsexciterswitchingwithaboardmountedrelay.Itincludes
2RMSdetectorswithadjustabletrippointsthatuseEPOTstomonitorexciterpower.Therearecontrolandstatus
interfaceconnectorsJ1AandJ1BthatgotoexcitersAandBrespectively.
Table4‐5showsthesignalsonthepinsof
connectorJ1A.ThesimplifiedblockdiagramfortheexciterswitchercardisgiveninFigure4‐7.
Figure 4-7 Exciter Switcher Block Diagram