Instruction manual

ACU-1000 Operations Manual
1-10 Interoperability Now
1.6.2 Card Cage
The chassis is a 19" wide EIA standard rack-mounted Eurocard card cage equipped with a
backplane board into which the modules are plugged. The module PC Boards are 100 x 220
mm. The card cage height is 5.25" (3U) tall, 19” wide, with a depth of 11". An AC input
module and power transformer assembly is located on a metal panel that is mounted to the
backplane. The AC module is a combination AC line filter, power cable connector, input
voltage selector, and fuse holder. The backplane interfaces the outside world via D-
subminiature connectors, and internally to the plug-in modules via 60-pin card edge connectors.
No active or passive electrical components reside on the backplane board.
1.6.3 PSM1-A Power Supply Module
The PSM-1A plugs into the left-most slot in the backplane. The power supply's backplane
connector is offset relative to the connectors for the other boards to prevent improper insertion
of the Power Supply Module in the slots reserved for the other cards. In turn, these other
modules cannot be plugged into the Power Supply slot. The power supply incorporates a dual-
primary line transformer with a bridge rectifier and filter capacitors to provide a +15V
unregulated DC bus. (The power transformer is mounted on the chassis, not the PSM-1A.)
The bus feeds a linear regulator that supplies all modules with +12VDC, and the bus feeds a
switching regulator that provides -12VDC. Each individual module contains a switching +5V
regulator operating from the +15V bus. . This is a 60W-output power supply, which furnishes
+12V, -12V, and +Bus (unregulated) voltage to the modules. This module will operate from
115/230 VAC as well as +12 VDC and Battery. A 1-Ampere capacity battery charger for a
lead-acid backup battery is built in.
1.6.4 HSP-2A
The HSP Module provides a means to locally monitor, configure and control an ACU-1000
system. The user can monitor audio via an internal speaker (or plug in an external speaker), or
use the handset provided. This handset includes a PTT switch to allow the user to key a cross-
connected radio via the HSP. Module control and configuration is made via a 3x4 keypad
(standard telephone layout). This keypad can be used to select a system module, either to
communicate with that module, or to set the module’s configuration parameters (input and
output levels, for example). For example, if the system contains a PSTN-2 module, the user
may place telephone calls manually using the HSP keypad and handset.
In addition to the front-panel handset jack, the HSP has input and output audio lines (0 dBm
nominal) and an external speaker output. All system voice prompt circuitry resides within the
HSP module.