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Aproio Management: George Fellingham


Expert Analog Design Engineer and Consultancy Business Owner with an active 30-year career resulting in a strong reference portfolio, Thirteen U.S. Patents (see List of Patents), and an emphasis in analog and power electronics for medical/industrial equipment and computer peripherals.  



Triple Ring Technologies | Newark, California | Apr 12 – May 17

Principal Analog Engineer at Triple Ring Technologies, a high-tech consultancy group and incubator for medical, industrial and security companies


  • Third-generation low-cost, high-efficiency electron beam deflection system for a scanned beam X-ray source (linear power amplifier with pulsed power supply rail controlled and monitored by an FPGA);

  • Laser power supply for phototherapy equipment;

  • Amplifiers and signal processing for Sensl silicon photomultiplier;

  • Low-noise light source drivers and sensing circuits for a diffuse optical tomography system and an optical renal function monitor;

  • Microwave loop-gap resonator for electron spin resonance oxygen sensor;

  • Test fixture electronics for drug pump.


  • Control loop of 80kV, 40W X-ray power supply.


Wright Speed, Inc. | San Jose, California |  Jan 11 – Apr 12

Senior Hardware Engineer at Wright Speed, an electric vehicle powertrain manufacturer.

  • Designed a 200kW PMSM traction drive power stage, 2.2kW DC-DC converter and 6kW battery charger for a hybrid delivery truck power train.


Fellingham & Associates | San Jose, California | Jun 95 – Dec 10

Principal Analog Design Engineer and business owner at Fellingham & Associates, a consultancy focused on hardware designs for medical and industrial electronics manufacturers, including:

  • Aerogen - Piezoelectric aerosol generator, drivers and control electronics for ultrasonic nebulizer & inhaler.

  • Alexza - Electronics for prototype drug delivery device.

  • BioElectromed - Signal processing development for bioelectric field imager.

  • Cardiac Mariners –Second-generation 2kW linear amplifier for magnetic electron beam deflection in scanned-beam X-ray system.

  • Cardiovention - FPGA-based air purge valve controller for heart-lung bypass machine. EMI system debug.

  • Dean Miller Associates - Medical RF ablation power sources (3W to 200W at 500kHz), high-speed high-voltage Q-switch driver and other support circuits for medical laser.

  • Dimatix - Discrete transistor power amplifiers for ink jet nozzle drive.

  • Doggicam Systems - Electronics and microcontroller firmware for 35mm motion picture camera remote head, motion capture/playback system, gyro stabilizer, power slide and super slide.

  • Hybrid Networks - Upstream receiver line card for broadband wireless internet access, wireless modem debug – RF circuit design and FPGA design using Altera devices with VHDL.

  • Litrex - FPGA-based ISA-bus inkjet print head driver card, programmable waveform driver-per-nozzle inkjet head driver.

  • Nektar - Inhaler electronics debug, aerosol generator test equipment development.

  • Nonsequitur Technology - Ion beam deflection system, USB analog I/O board for system control.

  • Norand Corporation - Switching power supplies and battery chargers for hand-held computers.

  • Panelvision Technology - Electron gun and deflection electronics, panel drivers for LCD panel tester.

  • Pocket Science - Analog design, ESD debug for pocket email device.

  • Specialized Bicycles - Bike light electronics.

  • Sportbrain - Analog ASIC test board.

  • Terumo Mission Medical - Specified and tuned DSP motor controller for cell-separating blood pump, produced electronics for experimental cell separator, centrifuge blood-level sensing, step motor drives, EMI debugging.

  • Topaz Technologies - Piezoelectric print head drive amplifier, long-range IR paper sensor for ink-jet printers.

  • Triple Ring Technologies - Multi-channel photomultiplier amplifier, multi-channel bio-impedance measurement system front end, low level optical measurement system hardware, MEMS oscillator, and scanned beam X-ray system electronics.

  • Other (Private Enterprise) – Drive electronics for a thermal perfume dispenser; spark ignition for small gas engines; and remote controlled pan-tilt head for digital SLR cameras.


Cardiac Mariners | Los Gatos, California | Aug 93 – Jun 95

Senior Analog Engineer at Cardiac Mariners, a scanned-beam X-ray systems manufacturer.

  • Designed and built a 96-channel video amplifier/discriminator for a multi-channel scintillation detector (input pulses are typically 50ns by 100mV).   

  • Developed a first-generation liquid-cooled scan amplifier board, providing electron beam deflection, focus and astigmatism correction, including a beam stepper capable of moving one pixel in 100ns.


Raster Graphics | Sunnyvale, California | Nov 99 – Jul 93

Senior Electrical Engineer  at Raster Graphics Inc., a manufacturer of electrostatic plotters. 

  • Designed two generations of analog electronics for the writing head on D and E-size plotters. Secured Regulatory Agency - Safety and EMI - Approvals with UL, CSA, TUV, FCC, VDE and VCCI standards. 

  • Designed multi-output (5V to 500V) power supplies up to 400W with power factor correction and motor driver/sensor boards. 

  • Developed a high-density thick film resistor process, test hardware and software. 

  • Supervised the development of a high-voltage IC tester for head drivers.

Circadian | San Jose, California Jun 87 – Sep 88

Senior Electrical Engineer at Circadian, San Jose, CA, a medical electronics manufacturer.

  • Redesigned a hybrid EKG instrumentation amplifier to improve yield and reduce cost by eliminating active trimming. 

  • Rescued a treadmill motor drive project, putting it back on schedule by replacing an unreliable 1 kW MOSFET motor drive with an off-the-shelf SCR drive. 

  • Solved EMI problems on analog tape decks in treadmill and Holter monitor systems.


Oximetrix/Abbott Labs | Mountain View, California | Jan 84 – Jun 87

Member of Technical Staff at Oximetrix/Abbott Labs, a medical instrument manufacturer.

  • Developed analog electronics for Life Care 5000 (Plum) IV pump — from concept to pilot production.  Development Included: Ultrasonic-bubble and strain-gauge pressure sensors and their electronics; step motor drives; power supply/battery charger; software algorithms for testing fluid valves with a pressure sensor, and for software damping of step motors. 


DV International | Saratoga, California | Jan 83 – Dec 83

Electrical Engineer at DV International, a cartridge tape drive manufacturer. 

  • Developed prototype cartridge-speed and head-position servos and a read-head amplifier for a high-performance cartridge drive.


CSIR | Pretoria, South Africa | Jan 82 – Jan 83

Research Officer at National Institute for Aeronautics and Systems Technology, CSIR.

  • Researched and evaluated applications for digital adaptive filtering.  Built and tested analog adaptive filter.



BSc | Electrical Engineering, with Honors, from University of Cape Town, South Africa. Postgraduate courses in control systems and stochastic signal processing at University of Pretoria.

Other | US citizen. IEEE member.



US7757632 - Waveform generator for microdeposition control system. Issued: July 20, 2010.

US7673820 - Subminiature thermoelectric liquid dispenser. Issued: March 9, 2010.

US7449070 - Waveform generator for microdeposition control system. Issued: November 11, 2008. Company: Ulvac, Inc.

US5682412 - X-ray source. Issued: October 28, 1997. Company: Cardiac Mariners, Inc.

US5191795 -  Ultrasonic detector. Issued: March 9, 1993. Company: Abbott Laboratories.

US5181050 - Method of fabricating an integrated thick-film electrostatic writing head incorporating in-line-resistors. Issued: January 19, 1993. Company: Raster Graphics, Inc.

US5128697 - Integrated thick film electrostatic writing head incorporating in-line resistors and method of fabricating same. Issued: July 7, 1992. Company: Raster Graphics, Inc.

US4977416 -  Integrated thick film electrostatic writing head. Issued: December 11, 1990. Company: Raster Graphics, Inc.

US4950244 - Pressure sensor assembly for disposable pump cassette. Issued: August 29, 1990. Company: Abbott Laboratories.

US4944191 - Ultrasonic detector. Issued: July 31, 1990. Company: Abbott Laboratories.

US4821558 - Ultrasonic detector. Issued: April 18, 1989. Company: Abbott Laboratories.

US4818186 - Drive mechanism for disposable fluid infusion pumping cassette. Issued: April 4, 1989. Company: Abbott Laboratories.

WO1996025024 - X-ray Source. Issued: August 19, 1996. Company:  Cardiac Mariners, Inc.

EP0871973 - X-ray Source. Issued: May 28, 2003. Company: Cardiac Mariners, Inc.

EP0496436 - Device for detecting the absence of a liquid in a conduit. Issued: July 29, 1992. Company: Abbott Laboratories.

EP0495538 - Device for detecting air in a fluid pump cassette. Issued: April 15, 1992. Company: Abbott Laboratories.

George Fellingham
Aproio: we analyze, design, build & test medtech and other highly regulated products
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