Using your Dream Player MC
Page 9
Dream Player MC – User Manual
3.3 Trigger Input Terminal Strip
More than simply playing an audio file, your Dream Player MC is capable of acting
and reacting based on input from you or the devices it is controlling. This section
describes the electrical connections for the Trigger Inputs.
The Trigger Inputs of the Dream Player are optically isolated which means you can
wire the inputs so that they are electrically isolated from the Dream Player. Why is
this important? Because sharing a common ground between an Audio Playback system
and any other system can (and usually does) create ground loops and noises such as
‘buzz’ and ‘hum’.
By isolating the Trigger Inputs, we have removed this problem for you!
As a convenience to your wiring, you may use the power supplied on the Trigger Input
Terminal Strip, but doing so will defeat the isolation offered by the Dream Player.
If you are simply wiring switches or buttons, there isn’t much chance of a ‘ground
loop’ or ‘noise’, so we give you the best of both worlds.
Figure 1 – Trigger Input Terminal Strip Pinout (P4)
Terminal Name
Description
1
GND
Convenience Power Supply Ground
2
Trigger-1
Opto-Isolated Trigger #1 Input
3
Trigger-2
Opto-Isolated Trigger #2 Input
4
Trigger-3
Opto-Isolated Trigger #3 Input
5
Trigger-4
Opto-Isolated Trigger #4 Input
6
POS
Opto-Isolator Shared Power Input
7
5V
Convenience Power Supply (5VDC)
The trigger input terminals (Trigger-1 to Trigger-4) provide connection to the low-side
(Cathode) of the LED in each opto-isolator. Current limiting resistors are built-in, so
you can simply connect any Trigger Input to GND to cause the Trigger to occur.
Terminal #6 (POS) is connected to the high-side (Anode) of all 4 opto-isolators.
Typically, Terminal #6 is connected to the power source to be used for the trigger
inputs. This can be an external power source, or Terminal #7 (5V) if you do not need
to isolate the Dream Player ground. The internal current limit resistors are suitable for
voltages from 5VDC up to 24VDC. If higher voltages are required please contact us to
determine suitable added current limit resistors.
Terminal #1 and Terminal #7 provide a local power source that is not isolated from the
Dream Player, but can be used to simplify wiring when using push-buttons, relays, or
other inputs that don’t require optical isolation.
