Centrifuge Calibrator

1
Centrifuge Calibrator
Group 18 Presents
BME 401 Progress Presentation

• Yu-Chen Su (Ray)
• Nicholas Adam Thaera
• Zhou-Yuan Zhang (Jimmy)
• Mentor Dr. Kurt Thoroughman

Monday, October 30, 2006
2
Recap

• Engineering World Heath
• Provide means of verifying speeds of old
  centrifuges for
• Underdeveloped countries
• Secluded regions
• Lower-income communities
• Corrected 1 per unit in quantities of 5!!

Centrifuge CalibratorMechanical or electrical
device for verifying the RPM of a centrifuge.
Must bereusable and applicable to a very wide
range of centrifuges. Separate devicesfor each
RPM calibration is acceptable.Relevant
additional specificationsCost lt1 in quantities
of 5
Engineering World Health. lthttp//www.ewh.org/gt
3
Recap

• Completion of Design December 11, 2006
• Cost of Production 1 per unit in quantities
  of 5
• Size 2cm2 by 3mm for circuitry, no limit for
  display
• Mass 50g
• Detection Range 0 20,000 RPM
• Power Supply dc power (battery) 1.5 V
• Compatibility Able to be installed on most
  laboratory benchtop centrifuges (80 of
  centrifuge models)
• Accuracy Reports rpm within 10
• Durability Robust and lasts 5 years
• Interface Analog pointer display
• Safety Adheres to safety guidelines
• Operating Temp Room temperature (25C 20C)
• Noninvasive Easily installed, requires 1 hour

4
Recap

• Completion of Design December 11, 2006
• Cost of Production 1 per unit in quantities
  of 5
• Size 2cm2 by 3mm for circuitry, no limit for
  display
• Mass 50g
• Detection Range 0 20,000 RPM
• Power Supply dc power (battery) 1.5 V
• Compatibility Able to be installed on most
  laboratory benchtop centrifuges (80 of
  centrifuge models)
• Accuracy Reports rpm within 10
• Durability Robust and lasts 5 years
• Interface Analog pointer display
• Safety Adheres to safety guidelines
• Operating Temp Room temperature (25C 20C)
• Noninvasive Easily installed, requires 1 hour

5
Design Alternatives I

• Mechanical Counter
• Counts the number of rotations the centrifuge
  rotor makes.
• Exhibits internal friction.
• Wear-down issues.
• Out of budget range, gt1

http//www.scancon.dk/encoders/Nano/SCHO9.htm
6
Design Alternatives II

• Completing an Electrical Circuit
• Counts revolutions of centrifuge using the
  completion of an electrical circuit.
• Centrifuge rotor spins at high speeds, difficult
  to make exact contacts
• Requires complicated setup in a small space.

http//www.uspto.gov/web/patents/patog/week44/OG/h
tml/1300-1/US06960158-20051101-D00000.gif
7
Design Alternatives III

• Optical Sensor
• Photodetector detects brightness or hue of a
  visual stimulus to keep count.
• Consequently, recording the number of stimulus
  per unit time leads to the measurement of RPM.
• VERY EXPENSIVE!

? rotational rate n number of stimuli
received N number of stimuli per revolution t
sampling time
8
Design Alternatives IV

• Vibration Sensing
• Piezoelectric crystal transforms mechanical
  energy into electrical energy.
• Use the resulting electrical voltage change per
  unit time to measure RPM.
• Requires massive computational power and
  compiling statistical data.

9
Design Alternatives V

• Hall Sensor System
• A system that measures the rotation of a shaft
  displays RPM measurements.
• Hall-effect sensor, requires strong enough
  magnetic fields.

http//www.autobytel.com/images/2006/Honda/CivicSi
/400/2006_Honda_CivicSi_inguage.jpg
http//news.thomasnet.com/news/sensors_monitors_tr
ansducers/740
10
Pros and Cons of all Designs
11
Design Decision
HALL SENSOR SYSTEM IS THE WAY TO GO
12
Hall Sensor System

• The Hall Sensor system will be consisted of five
  major parts
• Hall-effect Sensor
• Electrical Counters
• Timer
• Power Supply and Wiring
• Display

Placed on a circuit board!
13
Hall-effect Sensor

• Sensor placement in the centrifuge.
• The sensor is located on a circuit board along
  with electrical counters, timer, power supply,
  and wiring to the display.

Modification
14
Hall-effect Sensor
http//www.micronas.com/products/by_function/hal_2
xy/product_information/index.html
http//upload.wikimedia.org/wikipedia/en/7/7e/Hall
_sensor_tach.gif
15
Electrical Counters

• The digital Hall-effect sensor will output a
  square wave clock signal that will serve as the
  input to a 4-bit electrical counter.
• The 4-bit counter will count on the falling edge
  of the square wave (ripple counter).

http//www.eelab.usyd.edu.au/digital_tutorial/part
3/sa-op.htm
16
Electrical Counters

• The 4-bit ripple counter can display the 15
  decimals (numbers 0-15).
• Each counter then outputs binary numbers to the
  display.

http//www.kpsec.freeuk.com/counting.htm
17
Display
http//www.kpsec.freeuk.com/counting.htm
http//www.kpsec.freeuk.com/counting.htm
18
Timer

• The timer unit will be installed on the circuit
  board.
• The timer is going to be an internal component of
  the system, meaning, the time will not be
  displayed.

http//www.fairchildsemi.com/ds/NE/NE555.pdf
19
Power supply and Wiring

• The battery will also be installed on the circuit
  board (not included, purchased separately).
• Wiring is needed to link the battery to the rest
  of the components on the circuit board.
• Wiring also sends the output from the electrical
  counter to the display (the only part of the
  system not on the circuit board).

http//www.datamath.org/Batteries/BP7_Repair.htm
20
Hall Sensor System Diagram
21
Preliminary Costs
22
Design Schedule
23
Team Responsibilities

• Nick
• Preliminary Presentation
• Webpage and 3D Modeling
• Mechanics, Mathematics
• Display
• Ray
• Progress Presentation
• Electrical Counter
• Power Supply and Wiring
• Patents, Coordination
• Jimmy
• Final Presentation
• Hall-effect Sensor
• Timer
• DesignSafe Analysis

24
References

• http//www.ewh.org/
• http//www.scancon.dk/encoders/Nano/SCHO9.htm
• http//www.autobytel.com/images/2006/Honda/CivicSi
  /400/2006_Honda_CivicSi_inguage.jpg
• http//news.thomasnet.com/news/sensors_monitors_tr
  ansducers/740
• http//www.micronas.com/products/by_function/hal_2
  xy/product_information/index.html
• http//www.uspto.gov/web/patents/patog/week44/OG/h
  tml/1300-1/US06960158-20051101-D00000.gif
• http//upload.wikimedia.org/wikipedia/en/7/7e/Hall
  _sensor_tach.gif
• http//www.eelab.usyd.edu.au/digital_tutorial/part
  3/sa-op.htm
• http//www.kpsec.freeuk.com/counting.htm
• http//www.fairchildsemi.com/ds/NE/NE555.pdf
• http//www.datamath.org/Batteries/BP7_Repair.htm

25
Questions