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Transcript of Outline Introduction & BackgroundSystem Description & DiagramSpecificationsDesign – Four...
Outline
211/22/2006
IntroductionIn today’s business environment, the US sensor
market is expected to grow at an annual rate of
4.6%, to reach approximate $7.6 billions by 2009.
Increased sensor demand will bring an increase
in production and testing capacity.
Our objective is to design a tool and establish its
technical requirements, in order to speed up the
testing of sensors in the manufacturing process.
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BackgroundSensor is a device that responds to a physical stimulus,
such as thermal energy, electromagnetic energy,
acoustic energy, pressure, or motion, by producing an
electrical signal.
Most sensors are electrical or electronic although other
types exists.
Electrical voltage sensors vary in terms of performance,
specifications, optional features and environmental
operating conditions.411/22/2006
System DescriptionThe system described will focus on testing electrical
voltage sensors and all tests are assumed to be done at
room temperature.
The system will test newly built sensors and compare it
against a reference sensor known as a “good” sensor.
The testing tool will lit a green light for a “Pass” unit
and a red light for a “Fail” unit.
The system consists of four stages: differential stage,
rectifier stage, comparator stage, and selection stage.
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System Diagram
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Design
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1. Differential Block
Potentiometers are used
to simulate the sensors
Upper POT is the tested
sensor
Lower POT is the
reference sensor
Difference between two
sensors is amplified (Gain
= 30)
The difference can be
either positive or negative
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2. Rectifier Block
The input to the rectifier
could either be positive or
negative.
The purpose of the
rectifier is to take the
absolute value of the input
voltage.
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3. Comparator Block
The absolute value of the
difference is compared to
the threshold voltage.
The threshold voltage
can be adjusted according
to our specifications.
The output can either be
positive or negative.
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4. Selection Block (Pass)
If the input voltage is
negative, Q1 is cut-off, Q2
is in the active region.
Green LED lights up
which indicates the sensor
passed the test.
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4. Selection Block (Fail)
If the input voltage is
negative, Q2 is cut-off, Q1
is in the active region.
Red LED lights up which
indicates the sensor failed
the test.
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Selection Range
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Selection Range (2)
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Future DevelopmentDevelop the testing tool such that other types of
sensors can be tested.
The testing tool can be made portable, so that it
can be used in different locations.
Digital display can also be added for input and
output observations.
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ReferencesBelusov, Alex “Simple procedure test transducer” EDN, March 1, 1996, pg 144
Frank Keys, “All Types of Sensors”,
http://www-sensors.com/sensors-applications.html
Sensorsoft Corporation, “Real-time Contract and Voltage Sensor
Specifications’’, 2005-2006
Wikipedia, Sept. 2006, http://en.wikipedia.org/wiki/Sensors
Telecom Glossary 2K,
Feb.2001, http://www.atis.org/tg2k/_sensor.html
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