Aux Control Port; 10 V Zener; IQ Mixer / Multiplexer- Page 19

Page 19

IQ Mixer / Multiplexer  Hardware Installation

Rev. 0

Fig. 3.22  A 12x8 Mixer Using 8 Mixer/Multiplexers

By using several units and a combination of parallel
inputs and stacked outputs, larger mixing configu-
rations (12x8, 24x4, etc.) can be created as shown
below:

3.4  Connecting Auxiliary Devices (Step 4)

Auxiliary devices, external to the 

IQ System, can be

turned on and off using the Aux port on the mixer/
multiplexer. For example, auxiliary cooling for an
amplifier equipment rack can be controlled using
the Aux port to control a solid state relay which in
turn controls a cooling fan. This is shown below in
Figure 3.23:

AUX

CONNECTOR

GND

10 V

1

3

2

AUXILIARY

EQUIPMENT

110 VAC

SOLID

STATE
RELAY

(C 7308-7)

+

–

INPUT

Fig. 3.23  Sample Auxiliary System Wiring

maximum of 16 mA. This is shown below in Figure
3.24.

Notice in Figure 3.24 that the Aux port also has the
capability to receive a signal across pins 2 (+) and
1 (ground). It is a high impedance input and in-
cludes a pull-down resistor.

OUT

AUX

CONNECTOR

GND

1

3

1.5 K ohm

+24 V

IN

(LSTTL)

+5 V

20 K

100 K

2

10 V Zener

Fig. 3.24  Internal Auxiliary Circuit

SMX-6

SMX-6

MPX-6

MPX-6

MPX-6

MPX-6

MPX-6

MPX-6

MAIN

OUT

STACK
IN

PARALLELED

INPUTS

6x8

12 INPUTS

8
OUTPUTS

STACKED
OUTPUTS

6x8

The solid state relay shown (Crown part number C
7308-7) can be ordered from Crown.

The Aux port uses a male 3-pin mini XLR connector
which is located above the DB25 connector (Figure
2.1). Use a Switchcraft

®

 TA3F cable connector or

equivalent to make the connection.

When the Aux port is turned on by the 

IQ System it

provides 10 VDC across pins 3 (+) and 1 (ground).
An internal 1500 ohm resistor limits the current to a