Dan Noël, DC Power Supply Expert

Design ~ Verification ~ Simulation ~ Failure Analysis ~ Evaluation ~ Improvement

& Leadership


DC Power






From 1987 to 1990, Dan worked as a Project Engineer for Power-One, where his technical expertise and personal energy set new design and development benchmarks:

  • Dan was a principal contributor to the development of the first truly modular commercial AC-DC power supplies in the kW range. In particular, he was famous for leading, in 1988, the crash development of a 360 W tripe output magnetic amplifier forward converters' family, some of which still appeared in 2009 catalog.
    • Dan's team inherited project much behind schedule
    • Dan quickly exposed many errors and risks in proposed design, rushed a deep redesign while attempting to keep major components already procured and motivating team to work at hellish pace
    • Dan simultaneously tested/modified the first breadboard and directed modifications on the fly to a series of prototypes under construction
    • Working engineering prototypes were presented at Wescon show 6 weeks after Dan took over
  • Dan exposed some designs flaws in and directed swift redesign and crash-development of robust and effective EMI filter for above-mentioned power supplies
  • Dan also designed a family multi-output integrated magnetics resonant converters from 40 to 130 W slated for high-volume application:
    • Developed and exposed a simple, yet thorough theory of operation
    • taught it to the whole engineering department as a morale-booster
    • Explained quirky aspects of operation through simple graphs and reminders of fundamental laws of electromagnetism
    • Wrote technical description for the (successful) patent application
    • Controlled specifications of primary and secondary control ASICs, hardly modified them after giving them to IC vendor, closely guided vendor on detailed aspects of ASIC design
  • In 1989, Dan developed an Excel-based tool to extract design guidelines from multiple PSpice simulations in order to speed up the then-envisioned redevelopment of mass-produced linear power supplies:
    • Excel automatically generated multiple PSpice nets with various design and operational parameter deviations
    • These nets were simulated overnight on a PC
    • Excel collected the simulation results and displayed them in a cohesive, tabular fashion
    • This system made it straightforward to predict the influence of design parameters on the performance of a given circuit

Outside of Power-One, Dan was involved in designing and developing DC power supplies, mostly auxiliaries for high power inverters:

  • Supply GTO drive off auxiliary 24 V vehicle power
  • Supply IGBT drive off 24 V supply
  • Supply 250 V DC off 480 V battery to drive contactor
  • Linear 550 V DC to 450 V DC adapter to be developed on an emergency basis
  • Various 24-24 VDC converters to isolate circuits over high voltage barriers
  • Quickly corrected a few nagging problems in a 200 W Power Factor Correction system
  • Common requirements were high reliability and ease of procuring/manufacturing in low volume

Dan also developed till the engineering proto level a 600 W power supply that would convert the 400 V off an electric car battery into 12 V to charge its auxiliary battery and feed its auxiliary circuits. Paramount were reliability, error-free process and cost.

Since Dan's days at Power-One, low power DC supply technology has progressed dramatically, spurred by ever more stringent requirements for smaller size, lower costs, better reliability, lower voltages, higher currents, lower losses...

  • Ubiquity of PFC (Power Factor Correction system)
  • Synchronous rectification reduces losses in low voltage circuits
  • Complex control ICs provide sophisticated switching control and communication
  • Multiphase converters and cascaded converters answer elegantly the need for stable low voltages under stiff current transients