Control Output Terminal Strip - PRICOM Design Dream Player MK2 User Manual

Using your Dream Player MK2

3.4 Control Output Terminal Strip

The Dream Player is capable of controlling many types of devices and loads connected to
the Control Outputs. This section describes the electrical connections for the Control
Outputs.
The Control Outputs of the Dream Player are not isolated in any way from the Audio
Ground of the Dream Player. Why is that 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‟. If grounding problems become an
issue for your application, an external relay can be used to isolate the load from the
Dream Player.
As a convenience to your wiring, you may use the power supplied on the Control Output
Terminal Strip, but doing so will draw power from the internal 5V regulated supply used
to power the Dream Player. Use this convenience power for LED‟s, small relays, or
triggering another Dream Player, but if you intend to power any larger loads, please
consider an external power source for the Control Outputs.
Figure 5 – Control Output Terminal Strip Pinout (P6)
Terminal Name
1
2
3
4
5
6
7
The control output terminals (Output-1 to Output-4) provide connection to a Darlington
Transistor Array (Collector) used to Sink Power, but can not Supply Power. Each Output
is capable of sinking 400MA using the ULN2803 in the socket at U7. The Darlington
Array has its Emitters connected to the GND Terminal #1. External or Convenience
power can be used to power the load, but the reference and current ground will be using
GND Terminal #1.
Terminal #6 (Clamp) is connected to the Darlington Array protection diodes (Cathode)
for all 4 outputs. If you are driving an inductive load such as a relay, the Clamp terminal
should be connected to the power source being used for the load. This Clamp Terminal
will prevent the back-lash of the relay from destroying the Darlington Array. If simply
driving LED‟s this terminal can be left un-connected.
Terminal #7 provides a local power source that is not isolated from the Dream Player, but
can be used to simplify wiring if just powering LED‟s or other small loads. Power used
from this terminal can cause the on-board voltage regulator to become hot under load.
Description
GND Convenience power supply ground
Output-1 Control Output #1
Output-2 Control Output #2
Output-3 Control Output #3
Output-4 Control Output #4
Clamp Common Clamp Diode Connection
5V Convenience power supply (5VDC)
PRICOM Design Page 12