Testing Tool for Sensor Manufacturing

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Testing Tool for Sensor Manufacturing
ELG 4135 Electronics III Professor Riadh
Habash
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Outline
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Introduction

• In todays 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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Background

• Sensor 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.

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System Description

• The 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
Tested Sensor
Pass
Threshold
Selector
Differential
Rectifier
Comparator
Reference Sensor
Fail
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Design
Differential Block
Rectifier Block
Comparator Block
Selection Block
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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
FAIL
FAIL
PASS
Reference _at_ 50
Maximum _at_ 55
Minimum _at_ 45
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Selection Range (2)
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Future Development

• Develop 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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References

• Belusov, 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/wik
  i/Sensors
• Telecom Glossary 2K,
• Feb.2001, http//www.atis.org/tg2k/_sensor.html

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Thank You!