Shure SCM410E - Manual (Page 14)

14
Inhibit Function
For information on the inhibit function, refer to the Internal
Modifications section.
Remote Volume Control
The level of the Aux or Master output can be controlled from an
external VCA (Voltage Controlled Amplifier) such as the RU-
VCA1 from Radio Design Labs (Tel. 1–800–281–2683, or
www.rdlnet.com). To connect a VCA to the SCM410, proceed
as follows:
1. Connect the SCM410 Line output to the VCA line input.
2. Connect the VCA line output to the external device.
3. For remote Master level control, set the SCM410 Master
control to 5.
Diode Isolation of Logic Controls
Two or more control functions that use the same logic pins can
be isolated with diodes, as shown in Figure 27. With this modi-
fication, a channel can be muted by an overall group mute
switch, or by its own cough button.
GROUP
MUTE
COUGH
D = 1N4148 OR
EQUIVALENT
M1
M3
LOGIC
GROUND
BUTTONS
D D
DIODE ISOLATION OF LOGIC TERMINALS
FIGURE 27
External Logic Devices
SCM410 logic levels are directly compatible with TTL and 5V
CMOS logic families. Mixer logic may be used with 15V CMOS
logic if a pull-up resistor is used with each GATE output. See
Figure 28.
NOTE: For information on logic gate use, refer to the TTL
Cookbook and CMOS Cookbook, both by D. Lancaster,
Howard Sams Publishing Co.
15 V
POWER
+
–
SUPPLY
CMOS
GATES
5.1 K
G1
M1
O1
LOGIC
GROUND
15V CMOS
FIGURE 28
Digital Controls or Microcomputers
The SCM410 logic pins can interface with custom-designed
digital control circuitry or microcomputers for unlimited possi-
bilities of system control functions.