Studio Technologies 214 - Manual (Page 27)

Model 214 User Guide Issue 1, July 2014
Studio Technologies, Inc. Page 27
The heat-shrinkable tubing is provided
so that the connector terminals or “solder
cups” can be insulated from each other. It
will also provide some strain relief to the
solder joints. Be certain to slip the desired
length of tubing over the wire prior to
soldering a connection! (If the writer had a
dollar for every time he forgot to put tub-
ing on a wire (or slip on a connector shell)
before making a solder connection….)
Most of the 3-position headers on the
Model 214’s main circuit board assembly
are located close to their related input or
output connectors. Others headers pro-
vide access to functions such as the relays
or the remote control inputs. For details on
the headers please refer to Appendix B at
the end of this guide.
Remote Control Connections
Provision has been made on the Model
214’s printed circuit board assembly to
allow external switches or contact closures
to control the status of the audio signal
sent to the main and talkback output
channels. Two 3-position headers provide
access to the circuitry associated with the
functions. Refer to Appendix B for connec-
tion details.The input circuitry is “active
low,” with a 3.4 k ohm resistor connected
to +3.3 volts DC to act as a pull up. A
combination of resistors and capacitors
provide ESD protection.
Relay Contacts
The Model 214 provides two normally
open (not shorted) relay contacts for use
in specialized applications. One is associ-
ated with the main pushbutton and the
other with the talkback pushbutton. When-
ever audio is being sent to the main output
channel relay contact 1 will close (short).
And whenever audio is being sent to the
talkback output channel relay contact 2
will close (short). The two relays operate
under software control and are always ac-
tive, whether or not connections are made
to them.
Some “head scratching” or “brainstorm-
ing” should lead to a number of interesting
ways to take advantage of the relay con-
tacts. Applications could include keying
wireless transmitters, activating “on-air”
lights, and muting loudspeaker systems.
To utilize the relay contacts does require
the talents of a qualified technician. This
is because the Model 214’s enclosure
must be disassembled and the desired
wiring scheme implemented. For detailed
information on interfacing with the relay
contacts refer to Appendix B at the end
of this guide.
Pushbutton Backlighting
From the factory, white LEDs are installed
in the pushbutton housings. These LEDs
provide illumination (“backlighting”) of the
pushbutton switches. This may prove use-
ful for applications where adequate room
lighting is not available. It’s important to
note that the pushbutton lighting does not
provide a tally function; it is intended to
illuminate the pushbutton’s clear lens and
associated labeling.
The socket in each of the pushbutton
housings was originally designed to allow
insertion of a pluggable T-1 bi-pin incan-
descent bulb. But they are also compat-
ible with the more modern leaded T-1
LEDs. As of the time of writing this guide
the specific LED used at the factory is the
Kingbright WP7104QWC/D. If backlight-
ing is not desired it’s easy to remove the
LED lamps. The mating socket in each
pushbutton assembly is accessed by
carefully removing the pushbutton’s lens