Studio Technologies 230 2008 User Manual

Page 41

Model 230 User Guide

Issue 7, October 2008

Studio Technologies, Inc.

Page 41

their speciﬁed minimum. Typically, if the

Model 230 is being powered by an exter-

nal 24 volt nominal power source, normal

operation will continue until the input falls

to the 18-20 volt range. As the input volt-

age drops below this range the Model

230’s internal power supply will have

reduced stability, operating in this manner

until its low-voltage shutdown circuit halts

operation. Note that as the input voltage

moves down from 24 volts the input cur-

rent will rise proportionately to make up

for the loss of power.
Using the intercom line to provide Model

230 power shouldn’t prove to be a prob-

lem. Power supplies associated with

broadcast and production intercom sys-

tems are designed to support multiple

belt-pack and related devices. In the “big

scheme of things,” connecting a Model

230 shouldn’t add a signiﬁcant load.
If an IFB circuit is powering the Model 230,

maintaining the required voltage and cur-

rent is more critical. Should the voltage or

current fall below the speciﬁed minimum,

the Model 230’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 pow-

er and audio signals. If sufﬁcient amounts

of voltage and current are supplied to the

Model 230’s IFB input, the Model 230’s

power supply will draw a steady amount

of energy. This will not disturb the analog

signals on pin 1 (common for DC and au-

dio) and pin 2 (DC and channel 1 audio).

But if the Model 230’s power supply is

not supplied 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 corrupted 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 230’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 a 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 230’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 medio-

cre performance. That’s why Studio Tech-

nologies developed high-performance

IFB interface units. These products do an

excellent job of providing power and audio

to connected devices such as the Model

230. However, unlike other products, the

power supplied by the IFB circuits created

by these units maintains their output volt-

age all the way to their full rated current.

The result is being able to power more de-

vices over longer cable runs. In addition,

the audio quality of these units is superior.

For further information please refer to the

Studio Technologies website.