Studio Technologies 210 2012 - Manual (Page 28)

Issue 5, September 2012 Model 210 User Guide
Page 28 Studio Technologies, Inc.
It’s worth discussing what will happen if
either power source falls below its specified
minimum. Typically, if the Model 210 is be-
ing powered by an external 24 volt nominal
power source, normal operation will con-
tinue until the input falls to the 18-20 volt
range. As the input voltage drops below
this range the Model 210’s internal power
supply will have reduced stability, operating
in this manner until its low-voltage shut-
down circuit halts operation. Note that as
the input voltage moves down from 24 volts
the input current will rise proportionately to
make up for the
loss of power.
If an IFB circuit is powering the Model 210,
maintaining the required voltage and cur-
rent is more critical. Should the voltage or
current fall below the specified minimum,
the Model 210’s power supply circuit will
again become unstable. This will become
an issue as noise will be induced into
the IFB circuit’s audio signals. The reason
is simple: an IFB circuit “multiplexes”
3-conductors so that they carry both power
and audio signals. If sufficient amounts
of voltage and current are supplied to the
Model 210’s IFB input, the Model 210’s
power supply will draw a steady amount of
energy. This will not disturb the analog sig-
nals on pin 1 (common for DC and audio)
and pin 2 (DC and channel 1 audio). But if
the Model 210’s power supply is not sup-
plied with sufficient energy (volts x amps)
it will try to draw what it needs from the IFB
circuit, becoming unstable in the process.
The IFB circuit’s audio signals will be cor-
rupted by the power supply’s attempt to
draw enough power. Instead of nice clean
audio there will be squeaks, squeals, and
some awfully funky noises added. Again,
in a low-voltage or low-current situation,
no damage will be done to the Model 210’s
circuitry but correct operation will not be
possible.
In most cases maintaining the IFB circuit’s
required voltage and current shouldn’t be
a problem. But issues may arise due to
malfunctioning IFB circuit sources or
poor interconnect cabling. Typically, ex-
cessive cable length won’t be the cause
of problem. Generally, problems will be
caused by broken or damaged connec-
tor pins, dirty patch points, or damaged
(partially open) cable conductors. Measur-
ing the IFB circuit’s voltage and current
draw directly at the Model 210’s IFB input
connector will quickly identify if there’s a
power issue.
And now for another shameless “plug”
for other Studio Technologies products:
Frankly, most devices that supply IFB
circuits for broadcast applications use
outdated technology that provides
mediocre performance. That’s why
Studio Technologies’ developed high-
performance IFB interface units. These
products do an excellent job of providing
power and audio to connected devices
such as the Model 210. However, un-
like other products, the power supplied
by these units’ IFB circuits maintain their
output voltage all the way to their full rated
current. The result is being able to power
more devices over longer cable runs. In
addition, the audio quality of these units
is superior. For further information please
refer to the Studio Technologies website.
LED Colors
As previously described, two LED indica-
tors are associated with the main output
and are located directly above the main
output pushbutton switch. The red LED,
located on the left, is lit whenever the
main output is muted. The green LED,