Thompson Consulting
Some Consulting Projects
Following
are thumbnail sketches of some of our past consulting jobs in the areas of
analog design, magnetics, power electronics,
electrochemistry, and system design.
High Power Laser
Diode Modulator Based on Power Converter Technology
System
designed for driving 500 mW to 2.5W diodes, at full
optical power modulation up to frequencies of 10 MHz. The circuit is capable of
delivering up to 2.5 A to a laser load, with a 10 - 90 % switching risetime from lasing threshold to full optical power output
of less than 20 nanoseconds. The system has an active ripple reduction
circuit which reduces current ripple to less than 1% of full scale. A
current source is generated from a quasi-Buck converter technology for higher
efficiency than previous laser drivers, allowing removal of a bulky heat
sink. The PC board is connected to the laser through a microstrip cable. More detail is given in the paper here and in
the US
patent here.
Block diagram of laser diode driver
Transient response of laser output, 2 Watts full scale
vertical
Dual-Level
Semiconductor Diode Laser Modulators
Designed
3 Amp, 20 nanosecond risetime semiconductor diode
modulator for driving gallium arsenide laser diodes. The driver had a
dual-level diode ON current with adjustable overdrive amplitude and duration.
Patents are pending on dual-level drive concept.
Dual-level laser driver test
results using fast photodiode. 2 Watts optical power full scale
vertical, 50 ns/div.
Switching
Power Supply for CCD Camera
Designed
multiple output switching power supply for CCD
camera.
Included battery management and switching for multiple
battery inputs.
Series Laser Diode
Driver
Designed
3 Amp, series laser driver for driving 8 GaAs diodes
in series. Based on current-controlled Buck topology,
switching at 200 kHz with T filter at output for reduced magnetics
size.
Magnetically
Levitated Flywheel Energy Storage System
Assisted
in successful Phase I S.B.I.R. preparation for
magnetically levitated flywheel energy storage device. Performed stress
analysis, rotational loss calculations, finite-element analyses and magnetic
design. Assisted in successful Phase II proposal
preparation. Am currently acting as consultant on Phase II NASA SBIR "Shaftless, Magnetically
Levitated Flywheel Energy Storage System"
Multiple-Output
Offline Flyback Power Supply
Designed
wide temperature range, universal input offline flyback
power supply for ultrapure water instrumentation.
Laser Diode
Forensics
Assisted
client in determining causes of laser diode failures in spectroscope
application.
PC Board Spiral Inductors for Induction
Heating
Performed
study to determine design tradeoffs in planar spiral inductors and
transformers. Did comprehensive literature search, solved simplifying
cases, and ran finite element analyses for selected geometries. From
these studies, a set of design principles were identified.
Designed,
modeled, and analyzed small PC board spiral inductors for induction heating
applications. Developed approximation methods and scaling laws, and did 2D and
3D finite-element analyses (
Planar spiral inductor geometry
R/D for Ultrapure Water Instrumentation
Did
R/D and wrote SBIR for measurement of electrochemical
effects at water/electrode interface. Designed miniature
probe for measuring electrochemical effects at interface.
Electrochemical model of the water/electrode interface
Miniature Capacitive
Proximity Probe Analysis
Designed,
modeled, and analyzed small capacitive proximity probes. Developed
approximation methods, and did finite-element analysis (
Actuator Magnetic
and Thermal Design
Did magnetic and thermal design for small lens actuator. Designed switching actuator driver for higher bandwidth and power
delivery efficiency. Generated thermal models
and finite-element analysis for design.
Magnetic actuator with flexural lens mounting
Control System
Algorithm for Photovoltaically-Driven Inverter
Design
review and control system specification for 300 Watt 3-phase inverter system
driven from a photovoltaic source. PC board layout review.
Eddy Current Brakes
Designed
permanent magnet induction brakes for amusement park applications. Work
included magnetic optimization and materials specification for brake
electrodynamic and mechanical design. Have built
scale-model fixture for evaluating different braking geometries, including
linear brake arrays and Halbach arrays. Work with Magnetar
Corporation
Ranging System
Analysis
Identified
acoustic ranging system for client company. Analyzed possibility of using alternate schemes using laser diode
triangulation and time-of-flight measurements.
Audiotape Forensic
Analysis
Performed
forensic analysis on audiotape to determine if tape was modified/tampered.
Magnetic
Pick-and-Place
Re-designed magnetic pick and place system for improved reliability
Other Consulting Projects
- Designed systems for high
speed modulation of 100 milliWatt, 500 mW, 1W and 2W semiconductor diode lasers
- 200 kHz switching actuator
driver for lens positioning
- Assisted in design of 300
kHz flyback offline switching power supply
- Thermal analysis of
inductive proximity sensor
- Assisted in preparation of 3
SBIR proposals
- Assisted in proposal
preparation for semiconductor laser diode safety beacon for bicycle
application
- Phase-locked loop analysis
for induction heating application
Thompson
Consulting, Inc
Email: marctt@thompsonrd.com
Business website: http://thompsonrd.com/index.htm
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