Automated Calibration, Burn-In, and Test System
Design Requirements
Abstract
A test system will be created to automate the calibration and
quality control testing processes at FMR Audio. The system
will operate a single RNC1773 or RNLA7239 audio
compressor through the entire calibration, burn-in, and test
process and will contain all the instrumentation necessary
to perform these functions. Multiple test stations will be
needed to keep up with the company’s production rate, so
the test system must be inexpensive and compact, while
providing the accuracy necessary to assure quality products
are shipped.
Software
• Generates a sinusoidal test signal.
• Processes the returned signal to determine total harmonic
distortion (THD), noise, and frequency response.
• Determines an optimal setting for the digital trim pots on the
compressor.
• Indicates test status to the operator.
• Reports test results to an attached computer.
Hardware
• Outputs and smoothes the digital test signal generated by
the software.
• Conditions the returned signal by adjusting gain, filtering
out extraneous high frequencies
• Digitizes returned signal.
• Provides operator interface.
• Interfaces to compressor’s calibration port and computer.
•  The combined total harmonic distortion of the test
signal generator and THD measurement circuits
should be less than 0.001%
•  The noise floor of the test system in noise
measurement mode must be less than -100dBu
•  The frequency response of the system must be
repeatable to within ±0.01dB
•  The test system is capable of generating a
sinusoidal test signal with a frequency of
10Hz-120kHz.
•  The generated test signal has a THD of less than
0.001% at 0dBu.
•  The dimensions of the test system must be less
than 2”H x 8”W x 24”D
•  The test system must have a production cost less
than $400.
•  The test system must be capable of setting the
digital trim potentiometers on the FMR Audio
RNC1773 or RNLA7239 to a setting that produces
the lowest possible THD.
•  The test system must operate without any operator
intervention during the calibration, test, and burn-in
cycle.
•  The test system must power the device under test
for the duration of the burn-in period.
Design Team
• Jonathan Adams, EE, Project Manager
• Mark Demko, EE, Hardware Engineer
• Judicael Djoko, CpE, Software Engineer
• Michael Kyagaba, EE, Archivist
• 2012-2013 Senior Design Capstone Project • Dr. Joan Carletta, Faculty Advisor • Mr. Gregory A. Lewis, Senior Design Coordinator • Department of Electrical and Computer Engineering • College of Engineering • University of Akron •