WStephenWoodward

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Design Development Engineer

With more than 50 contributions to his credit, Steve Woodward is one of EDN's most prolific Design Ideas authors. His offerings started in 1974 with an idea entitled "Simple 10-kHz V/F features differential inputs," for which he won the annual prize for the best Design Idea. As a self-proclaimed "certified, card-carrying analog dinosaur," most of Woodward's ideas solve issues in that nebulous "nondigital" area of design engineering that gives us the thorniest problems. His Design Idea titles, such as "Self-heated transistor digitizes airflow" in 1996 and "Circuit controls microneedle etching" in 2003 demonstrate how he likes to adopt electronics to the physical world. Woodward is an instrumentation, sensors, and metrology freelance consultant to organizations such as Agilent Technologies, The Jet Propulsion Laboratory, the Woods Hole Oceanographic Institute, Catalyst Semiconductor, Oak Crest Science Institute, and several international universities. With seven patents to his credit, he has authored more than 200 professional articles. He has also served as a member of technical staff at the University of North Carolina. He lives with his wife, Clare, and sons in NC.


WStephenWoodward

's contributions
  • 07.29.2016
  • Circuit delivers constant power to a load
  • Late to the party, but why not just connect your capacitor C between your heater R and a variable-frequency F squarewave generator V? Then, so long as F is much slower than 1/RC, the pure AC power delivered to R will be... P = V^2 F C ...with less complexity and 100% efficiency.
  • 05.01.2008
  • Fast-settling synchronous-PWM-DAC filter has almost no ripple
  • Ooops! Correction -- nothing happens. Settling still occurs in a single cycle. The only difference is that some integration occurs before the sampling cap' starts tracking it, but the ultimately captured value is the same. Trying to answer questions about a circuit I designed a decade before will do that.