Suggested Logic Applications - Shure SCM810 User Manual

SUGGESTED LOGIC APPLICATIONS

This section contains suggestions on the uses of the SCM810's
logic capabilities. Note that uses of these functions are not limit-
ed to the listed applications. The user is limited only by individual
imagination and creativity. For additional suggestions and solu-
tions to installation problems, contact Shure's Applications
Group.
In the following paragraphs, the wiring diagrams refer to the
DB-25 connector pins shown in Figure 10.
Cough Button
The talker can turn off his or her microphone during coughing or
private conversations by installing an SPST pushbutton switch
between the MUTE IN and Logic Ground pins for each channel to
be modified (see Figure 12—Channels 1, 2 and 3 modified).
When a channel is muted, no audio is passed. (See "Dead Zone
on MUTE IN Defeat" in Internal Modifications section for more in-
formation on MUTE IN logic.)
M1 M3
M2
COUGH BUTTONS
FIGURE 12
Chairperson-Controlled Muting
The chairperson can, by activating a switch, silence all other mi-
crophones and be heard without interruption. For operation in
this mode, connect all the MUTE IN pins together except that of
the chairperson's channel, and wire an SPST pushbutton or
toggle switch between those MUTE IN and Logic Ground pins
(see Figure 13—the chairperson is shown as Channel 1).
An alternative to a switch is to connect the chairperson's GATE
OUT to the MUTE IN of other channels. When the chairperson's
microphone activates, all other microphones mute.
CH. 1
M3
M2 M4
CHAIRPERSON–CONTROLLED MUTING
FIGURE 13
LOGIC
GROUND
LOGIC
GROUND
M5 M5 M7
M6
Remote Channel-On Indicators
Remote indicators can be used to indicate when a talker's micro-
phone is on. Connect the LEDs and a 5-volt supply to the GATE
OUT pins as shown in Figure 14 (Channels 1, 2 and 3 shown
modified). To avoid switching clicks in the audio output, do not
ground the power supply negative terminal in the audio system or
rack ground.
IMPORTANT: If a single cable is used for the microphone audio
signal and the LED dc power, separate shielded pairs must be
used. Failure to carry the dc power on a shielded pair may result
in audible clicking due to capacitive coupling between the dc
power lines and microphone lines.
R
G1
R
REMOTE CHANNEL–ON INDICATORS
Disabling the Gating Function (Bypass)
To keep certain microphones on at all times, wire the desired mi-
crophone channel's OVERRIDE IN pins together to the Logic
Ground pin. The selected channels now function as they would in
a non-automatic mixer (see Figure 15—Channels 1, 2 and 3
modified).
O1
11
+
–
5 V POWER
SUPPLY
R
GROUND
G3
G2
R = 470 Ω
, 1/4 W
FIGURE 14
GROUND
O2
O3
GATING BYPASS
FIGURE 15
LOGIC
LOGIC