Magnetic Bearing
Critical Design Review
Team miniMuffin
Lauren Glogiewicz
Jacob Beckner
Kevin Bodkin
James Holley
Philip Terry
Level 0 Functional
Decomposition
Phil T.
Level 1 Functional
Decomposition
Phil T.
Level 2 Functional
Decomposition
Phil T.
Current Control
Iout = -Vin / Rmag
Jake B.
Electromagnets
• Electromagnets have inductance as circuit element
• Causes initial overshoot and slow rise to desired level
• Must be accounted for in design
Leveling Time = 2.7 μs
Rise Time = 20 ns
Jake B.
Sensor Circuit
• Sensor output current is
based upon the distance
away from the object
• Ideal distance to axle
from the sensor is
between 0.3” - 0.8”
• Beyond this, sensor data
will become unreliable
Kevin B.
A/D Converter
• Using microcontroller on-board A/D
• TI MSP430: 4 Channel 10-Bit 200 KSPS
• TI C2000: 7 Channel 12-Bit 4.6 MSPS
Kevin B.
Software FD
8x sensor distance in to FPGA
Convert distance error to current
8-12 bits per magnet sent to
current control via FPGA I/O
Kevin B.
Microprocessor / FPGA
Two possible microcontroller / FPGA controllers:
• TI C2000
o Up to 60 MHz
o Supports I2C and SPI
o On board A/D Converters
• Altera DE2 Board
o Up to 50 MHz
o 80 GIO Pins
o Ability to apply control in parallel
James H.
D/A Converter
• TI DAC7576
o 8 channel, 12 bits
o Up to 2.3 MHz communication speed
o I2C synchronous communication will be used
James H.
Magnet Test Bed
James H.
Magnet Test Bed
James H.
Timeline
• Milestone 1
o Floating 1D concept
o Focus on feedback loop design and interface
• Milestone 2
o 2D axle built and working
• Expo
o Fully 3D axle with horizontal stabilization
Lauren G.
Updated Budget
• We have received $1000 from UROP
• We will still apply for the EEF Grant
Item
Part No.
Cost
Quantity
Total Cost
Electromagnets
EM 200
$
41.61
15 $
624.15
Optical Sensors
Sharp GP2Y0D805Z0F
$
3.70
15 $
55.50
BJT
$
0.38
25 $
9.50
Op Amps
$
1.00
25 $
25.00
Capacitors
$
0.60
20 $
12.00
Resistors
$
0.60
20 $
12.00
Wire
Wire T Lead Plastic 22AG
$
18.00
5$
90.00
Nuts, Bolts, Screws
Aluminum (25 pack)
$
9.58
3$
28.74
Aluminum
6ft x 1/4" x 2"
$
30.22
1$
30.22
Machining
$
200.00
1$
200.00
PCB
$
60.00
3$
180.00
Shipping and Handling
$
10.00
6$
60.00
Posters/Presentation
$
70.00
1$
70.00
$
1,397.11
Total
Lauren G.
Questions?