Shure SCM410E manual Inhibit Function, Remote Volume Control, Diode Isolation of Logic Controls

INHIBIT FUNCTION

For information on the inhibit function, refer to the Internal Modifica- tions section.

REMOTE VOLUME CONTROL

The level of the Aux or Master output can be controlled from an exter- nal 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 iso- lated with diodes, as shown in Figure 14. With this modification, a chan- nel can be muted by an overall group mute switch, or by its own cough button.

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 15.

NOTE: For information on logic gate use, refer to the TTL Cookbook and CMOS Cookbook, both by D. Lancaster, Howard Sams Publishing Co.

+

5.1 K	15 V
	POWER

	–
	CMOS
	GATES
G1	O1

GROUP

MUTE

DD

M3

M1

D = 1N4148 OR EQUIVALENT

LOGIC

GROUND

LOGIC

GROUND

M1

15V CMOS

FIGURE 15

COUGH

BUTTONS

DIODE ISOLATION OF LOGIC TERMINALS

FIGURE 14

DIGITAL CONTROLS OR MICROCOMPUTERS

The SCM410 logic pins can interface with custom-designed digital control circuitry or microcomputers for unlimited possibilities of system control functions.

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