Protech Audio 902 User Manual
Protech
PROTECH
MODELS COVERED
®
INTEGRA III SYSTEM
MODEL 902
PRIORITY PAGING SWITCHER CARD
INSTALLATION & OPERATION MANUAL
902
The Model 902 Priority Paging Switcher Card is designed
for use in professional audio applications. Each unit fea-
tures six (6) paging inputs, one (1) line level output, and a
switch closure circuit for control of priority bypass relays,
or other paging functions.
Typical applications are public address systems in build-
ings such as airports, factories, hospitals, courthouses,
casinos, convention centers, libraries, hotels, racetracks,
and office buildings.
The mechanical construction of the Model 902 allows
mounting of up to ten (10) units in a Model 857B Card
Frame, or 9 units in a Model 858B Card Frame. Each
Model 902 card unplugs from the front of the card frame,
without the need for removing any wires from the rear
of the card frame. Spare units may be placed into service in
a matter of minutes.
Each Model 902 has six inputs, which are arranged in
a series configuration. Each input passes thru a number of
double-pole double-throw relays. Activating any higher
priority relay disconnects the relay chain at the selected
point, and allows the higher priority input channel to pass
thru to the output stage. Input stage number 6 is normally
used for background music, and is configured in the nor-
mally ON position. Activating any of the other five (5)
inputs will disconnect input number 6.
The Model 902 Priority Paging Switcher Card is balanced
at both the input and output stages. The output level may be
adjusted by using the on-board output level control trimpot.
The relay control circuits are activated by grounding the indi-
vidual control pins as indicated on the block diagram on page 3
of this manual. In addition to the paging input controls, ground-
ing any of the control pins will activate the priority bypass relay
control circuit. This circuit is usually used to activate bypass
relays in remote level attenuators. However, it may be wired to
any control circuit requiring no more than 1 amp of current at
24VDC.
All integrated circuits used in the Model 902 are mounted in
plug-in IC sockets, to facilitate maintenance of the system.The
DC power supply connections are protected by self-resetting
electronic fuses. If a card should malfunction, the electronic
fuses will disconnect the card from the power supply. The
same type of fusing is provided in the priority bypass relay
control circuit.
Other INTEGRA III SYSTEM cards, such as distribution
amplifiers or compressors, may be used in the same card frame
assembly, to allow construction of complete audio systems.
Each of these products is designed to provide the user
with high quality audio, for years of uninterrupted
service.
Model 902 Shown
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Protech Audio Corporation, PO Box 597, 192 Cedar River Road, Indian Lake, New York, 12842, Voice 518-648-6410 Fax 518-648-6395