Shure AMS880 User manual

222 HARTREY AVE., EVANSTON, IL, 60204 u S.A
DATA SHEET
AREA CODE 3121866-2200 CABLE: SHUREMICRO
TWX. 91 0-231 -0048 TELEX: 72-4381 MODEL AMS880
PONENTS
b
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VIDEO SWITCHER INTERFACE
The Shure Model AMS880 is a Video Switcher Interface
which expands the Shure Automatic Microphone System
[AMS] for use in video teleconferencing applications. The
heart of theAMS880 is an 8748microcomputer which ac-
tuates the remote-control input of a commercially available
video switcher in response to the action of an automatic
microphone mixer such as the Shure AMS4000 or
AMS8000. Video cameras covering individualmicrophones
are thereby activated when their microphones are ac-
tivated, causing the video presentation to smoothly follow
the flow of the audio discourse. Three additionaloptions are
also available. First, the AMS880 can select a particular
vidoo channel [such as a wide-angle camera] after a
predetermined period of audio inactivity. Second, the
AMS880 contains an "override" option that suspends
automatic action and permits external manual switch selec-
tion of a particular video channel, such as a graphics
camera. Third, a "disable" input is available to suspend all
automatic action and allow manual camera selection via
switches externally connected in parallel to the AMS880
outputs.
The AMS880 is designed for mounting in a standard 19"
equipment rack, or, using supplied feet, on any horizontal
surface. The unit is powered by an external power
transformer which is Listed by Underwriters Laboratories,
Inc.
SPECIFICATIONS
Inputs
Logic Gate Inputs: 8 plus logic ground
Open Circuit Voltage:
+ 5V
Resistance: 1 kilohm
Logic Status: Low
= channel gated on
lnput Protection: To 12V
Outputs [FET optically isolated; not connected to input
ground]
Off Resistance: Greater than 300megohms
On Resistance: Less than 200ohms
Switching Time: Less than 1 msec
Output Closure: Selected output will pulse closed for
250 msec; may [optionally] provide
maintained closure
Power
External power transformer: 120Vac + lo%,60Hz,
6W
Temperature Range
Operating: -7O to 57OC [20° to 135OFI
Storage: -1
8" to 71OC [0° to 1 60°F]
Dimensions
44.5mmHx483mmWx127mmD[1 3hin.x19in.x
5 in.]
Weight
1 .I kilograms [2.5Ib], including transformer
SuppliedAccessories
Adhesive feet for surface mounting; screws andwashers
for rack mounting; mating output connector [25-pin
DB25P type with separate solderable contacts, locking
screws and back shell with cable clamp]
INSTALLATION AND OPERATION
Controls, Indicators and Connectors
The front panel of the AMS880 contains a push-button
power-on switch and a green power-on indicator. The
rear panel contains a 1.2m
[4 ft] multiconductor ribbon
input cable which consists of eight channelGate Out logic
inputsand a logic ground. Color codingof theribboncable
is shown in Table 1
.
TABLE 1. INPUT CABLE CONNECTIONS
Color
Brown
Red
Orange
Yellow
Green
Function
Gate 1
Gate 2
Gate
3
Gate 4
Gate 5
Color Function
Gate 6
Purple Gate 7
Gate 8
White Ground
The rear panel also contains a connector for the external
power transformer, and a 25-socket subminiature D-type
output connector [DB25S type] with locking screw studs
for connection tothe remote-controlinput of avideo switch-
er such as the 3MVideo BridgingSwitcher Model 101.The
AMS880 is supplied with a matching 25-pin connector for
connection to the video switcher cable. Pinlsocket connec-
tions for the 25-socket connector are given in Table 2.
TABLE 2. OUTPUT CONNECTOR TERMINALS
Output 3
Output 4
Output 5
9 N.C.
11 Output Cornrnol
Ground
Ground
N.C.
17 N.C.
N.C.
22 N.C.
The printed circuit board contains two eight-station DIP
switches which provide option selection as follows. Factory
preset positions are given in boldface type.
Copyright 1982, Shure Brothers Inc
27A8044 [El]

TABLE 3. OPTION SWITCH FUNCTIONS
Switch 6 Station Function
lnput T~rne Delay
Autornat~c ldle Opt~on
Automat~c ldle T~nie
See Table 4
Select~on
Rotat~on Rate
O~sabled 2.7 sec
Output Mode Ma~ntaned
Pulsed
Overr~de Channel 1
Enabled Disabled
53-2 Overr~deChannel 2 Enabled
Disabled
53-3 Overr~de Channel 3 Enabled
Disabled
53 4 Overr~de Channel 4 Enabled
Disabled
53-5 Overr~de Channel 5 Enabled
Disabled
53-6 Overr~de Channel 6
Enabled Disabled
53 7 Overr~de Channel 7
Enabled Disabled
53-8 Overr~deChannel 8
Enabled Disabled
- - - -- - -- -- -
*Off posltlon IS marked OPEN, On posltlon 1s not marked
TABLE 4. AUTOMATIC IDLECHANNEL SELECTION
152-8pFEJ+s2i4-
Channel
Off
Off
Off
Off
On
On
On
On
Off
Off
On
On
Off
Off
Un
On
Off
On
Off
On
Off
On
Off
On
Installthe AMS88O as follows.
I. lf any changes from the factory preset optlons are
desired, removethe AMS880 cover and set option swit-
ches [S2, S3] for thedesired function [seetables
3 and 4
and explanations below]. Replace the cover.
2. Install the AMS880 in a standard 19-inch equipment
rack [screws and washers are provided] or on a horizon-
tal surface [protective feet are provided].
3. Fabricate a connecting cable between the video switcher
and the AMS880 usingthe supplied 25-pin DB25Ptype
connector. Install the cable between the video switcher
and the AMS880 output jack.
4. Connectthe leadsof themulticonductor lnput cable of the
AMS880 to the Gate Out terminals of the AMS mixer
follow~ngthe EIA color coding [brown-Channel 1, red-
Channel 2, etc. as shown in Table I]. Connect the
AMS880 white input lead [Ground] to the Channel 8
[AMSBOOQ]or Channel 4 [AMS4000]Loglc Groundter-
minal of the AMS mixer.
5. Connect the external power transformer to . the
AMS880.
6. Connect the power transformer to a 120Vac, 60 Hz
source.
Operation
With all equipment connected, turn the AMS880 on by
depressing the Power sw~tch.If no funct~onoptions have
been changed from their factory settings [using internal
switches 52 and S3], a given camera channel will be
selected after its AMS mixer channel has been on for
2.5
seconds. This input timedelay prevents changing cameras if
an AMS mlxer channel has been activated by a short sound
such as brief paper rustllng or chair squeaking. Note that
thetime delay can be decreasedfrom 2.5to
1.9 seconds by
movlng switch 52-1 to the "off" position.
Dur~ngperiods of inactivity, the last camera channel ac-
tivated will remain on. It two or more AMS mixer channels
are active s~multaneously,camera channel selection w~ll
rotate among those among those channels at a rateof 2.7
seconds per channel. The rotatlon action can be disabled by
movlng switch S2-7 to the "on" [non-OPEN] posit~on.
Options
Automatic ldle Opt~on
Internalswitches S2-2 through S2-6 are assignedtothe
automatic Idle channel function. When an automatlc Idle
channel has beenselected, cessation of activlty by the AMS
mixer for more than 6.2 seconds will cause the autornatlc
idle channelto be activated. This allows switching to a wide-
angle or a graphics camera when no one IS talk~ng.Normal
action is restored when any input is active for the selected
Input time delay of 2.5 or 1.9seconds.
Switch 52-2 turns the automatic idle function on or off.
Switch S2-3 chooses the automatic idletimedelay of 6.2or
8.8 seconds. Switches S2-4, S2-5 and S2-6 select,
through a binary logic code system [see Table
41, the
number of the channelselectedfor theautomatic idle opera-
tion.
Overr~deOption
Any or all input channels can he selected to overrlde the
automatlc channelselectronfunct~on
nf the AMS mixer The
selected override Inputs
will usually be actrvated by a manual
sw~tchclosure to ground, rather than an AMS mixer gate
output When S3-1 through 53-8 are enabled [turned on].
any overrlde lnput actlvated wlll take precedence over those
channels normally actlvated by the AMS mlxer operation If
more than one overr~deoption channel 1s enabled, the f~rst
Input actlvated will turn on Heleasrng all overrlde Input
switch closures to ground w~llrestore automatic AMS
m~xer-controlledactlon
Disable Option
An external switch closurefrom Output Connector pin23
topin 25[Ground] will suspendall autornatic action, allowing
any parallel-connected [external] switch closures between
Output Connector Common [p~n
11 ] and Output Channels
[pins 1 through 81 to control the vrdeo switcher's action.
Releasingthe Disableswitch closurewill immediatelyrestore
automatic action.
GUARANTEE
This Shure product IS guaranteed In normaluse tobe free
from electrical and mechanical defects for a per~odof one
year fromdate of purchase. Pleaseretainproofof purchase
date. This guarantee includes all parts and labor. This
guarantee is in lieu of any and all other guarantees or war-
ranties, express or implied, and there shall be no recovery
for any conseq~jentlalor incidental damages.
Carefully repack the unlt, insure ~t,and return
~t prepa~d
to: Shure Brothers Incorporated
Attention: Service Department
222 Hartrey Avenue
Evanston, Illinois 60204
If outsidethe UnitedStates, returnthe unit toyour dealer or
Authorized Shure Service Center for repair. The unit will be
returnedto you prepaid.

REPLACEMENT PARTS LIST
Parts that are readily ava~lablethrough local electronic parts distributors are not
shown on the Circuit Diagram.
-- - --
Reference
Designation
- -
C6
Dl-Dl9,
021-036
Description
-- ---- pp ppp - -. . . .
Capacltor. Electrolytic. 47wF,1OV
Capacltor, Electrolytic, 1000{LF,25V
Capacltor, Electrolytic, 4 7 wF, I OV
Dlode, Slllcon Computer. 75mA, IOOV
Diode. General Purpose Rectlfler, 1A, 100V
Dtode, L~ght-Emttt~ng.Green
Dtode, Zener. Overvoltage Translent Suppressor
Fuse 3AG.
' )A.250V
Connector, 25-Socket
Transistor, NPN, General Purpose
Varlstor Metal Oxide
Swttch, Push-Button, Power, SPST
Switch Assembly, Dual In-Line SPST
Integrated Clrcult, Schmitt Trigger Inverter
lntegrated Clrcult. Mtcrocomputer
Reslstor Network
Dpto-Isolator [Photon-Coupled Btlateral FET]
Power Transformer. Prtrnary 120Vac * 10%.57-63 Hz,
Secondary 22 Vac, 16VA. CT, wtth cable and connector
Voltage Regulator, Pos~tlve
Fuseholder
Crystal, Quartz
3 579545 MHz HC-18IW Holder
-- - - - - - . -- - -
shown on the followinglist. Their values are
-
- - - -- - - --
Manufacturer 6
Part Number
--
p- --
Sprague 503D476FOlOLA
Sprague 501Dl08F025QS
Sprague 199D475X0010BB1
Motorola 1N4002
Shure 86C8402
Motorola MPTE 5
Llttelfuse 31 2 500
AMP 206584-2
Shure 55A8013, 1TT NEI51
F2U103EE/01-003-00
TI SN74LS14N
Shure 86A8806. NEC pPD8748*
Intel 8748'
Bourns 431OR-101RC1
K
GE HIIF1
Shure 95A8048
Motorola MC7805CT
Littelfuse 102071
GTE ECG358
- .. . - .-
Programmed wtth operatlrig code
PRINTED CIRCUIT
BOARD
-
COMPONENT
SIDE
SOLDER
SlDE