CV
G
R
Driving One LED
I
≈
2v
R+40
Ω
Driving Lamps
2
N
3904
+
CV
10
K
Ω
G
G
CV
Driving Logic Gates
Equivalent Output
Circuit for Control
Voltage Out
CONTROL
VOLTAGE
40
Ω
GND
Relay Driver
2N3904
IN4001
+
CV
10K
Ω
RELAY
COIL
G
Control Voltage Out
When a microphone channel turns “on,” as indicated by a Selected Channel LED on the front
panel, the channel’s associated Control Voltage Out goes “high” (+4 VDC). This signal can be
used to light indicator lamps, switch speaker zones on and off, select video cameras, etc. The
control voltage should not be connected directly to an inductive load such as a relay coil, as
damage to the mixer may result. Several interface circuit possibilities are shown in Figure 5.
Figure 5. Control interface examples.
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