VPX power systems are a defense industry mainstay. New standards help boost efficiency by eliminating the need to over-specify supplies when handling outlier situations. GERALD HOVDESTAD BEHLMAN ELECTRONICS POWER Supplies have always been the problem child in electronic system design. Often, high-end systems are configured for specialized applications. As a result, power requirements tend to […]
Power Electronics Handbook
Choosing inductors for energy efficient power applications
Energy efficiency in power supplies can be as much about the inductors as about the circuit topology. A few simple calculations can prevent unpleasant surprises. CHRIS HARE, LEONARD CRANE COILCRAFT, INC. In high frequency dc-dc converters, inductors filter out the ac ripple current superimposed on the dc output. Whether the converter steps the voltage down […]
Energy efficiency in LLC Resonant Conversion Topologies
Designers are now investigating exotic power supply topologies in a quest for efficient operation. RICK BARNETT, ED FONTANA, JIM MONTGOMERY, EMBEDDED SOLUTIONS, GE INDUSTRIAL SOLUTIONS BUSINESS IT’S no secret that power converters increasingly emphasize energy efficiency. For example, 115-Vac computer power supplies must exhibit a 94% energy efficiency at 50% of their rated load to […]
Wireless charging efficiency: how to measure in the real world
by John Perzow, Wireless Power Consortium When it comes to energy efficiency, there are significant differences in competing wireless charging methods. There are a lot of claims made about the energy efficiency of wireless charging schemes. Engineers are understandably skeptical. After all, it is hard to envision how two induction coils sitting some distance away from each […]
GaN components boost power density in supplies
by Eric Persson, Infineon Technologies To understand why gallium-nitride components shrink the size of power supplies, examine how they dissipate energy at high frequencies. Silicon power FETs have come a long way over the past 35 years. Modern high-voltage superjunction FETs have developed over the past 15 years to even exceed what was thought to […]
Multiple charging modes from a single amplifier
by Michael A. de Rooij, VP, Applications Engineering, Efficient Power Conversion Though there are two standards for charging appliances wirelessly, a single circuit can be devised to serve as a charging node for both of them. The good news about wireless charging techniques is that they do away with messy wiring that tethers phones and […]
How and when MOSFETs blow up
by Majeed Ahmad High temperatures and operating conditions outside the safe operating area can sabotage MOSFETs used in switching circuits. The MOSFET (metal-oxide-semiconductor field-effect transistor) is a primary component in power conversion and switching circuits for such applications as motor drives and switch-mode power supplies (SMPSs). MOSFETs boast a high input gate resistance while the […]
Compensating for temperature in high-frequency rectifier diodes
by Koji Ikeda, Sanken Electric Co. and K.C. Nishio, Allegro Micro Systems Over-temperature can be a problem in high-performance switching supplies. New power rectifier diodes build in safeguards to head off heat build-up. Pulse-width-modulated converter and amplifier designs tend to spend much of their time handling significant levels of electrical current. High currents tend to […]
A close look at the Level VI power supply spec
by Jeff Schnabel, CUI Inc. DOE power supply efficiency specifications target a broader array of power supplies to save energy and reduce greenhouse-gas emissions. Market enthusiasm for new high-tech devices is undiminished. The Consumer Electronics Association, in its July 2015 U.S. Consumer Electronics Sales and Forecasts report, predicted a total industry revenue rise of 2.4% […]
Basics of designing with permanent magnets
by Stan Trout, Owner/Metallurgist, Spontaneous Materials It can be tricky to correctly specify magnetic materials for power circuits and actuators. An understanding of definitions and common properties serves as a good starting point. Though magnetic materials are widely used in power components, engineers frequently have misunderstandings about their magnetic properties. For example, the energy product […]
