It pays to know techniques for mitigating leakage current and over- voltages in uses where several supercapacitors work in parallel. Michele Kinman Advanced Linear Devices Inc. In applications requiring rapid charge/discharge cycles or short-term energy storage, you’ll often find supercapacitors connected in series or parallel. However, there’s a potential problem when supercaps are wired together […]
FAQ
How wide bandgap technologies stack up
Cutting-edge power device technologies all have a niche. Here’s a rundown on the applications in which each one likely fits. Dr. Gerald Deboy, Dr. Peter Friedrichs Infineon Technologies The process of converting electrical power to different ac and dc levels and to mechanical motion has changed dramatically over the years. The development of “switched-mode” techniques […]
The basics of specifying ground-fault interruption equipment
Not all ground-fault interrupters are designed to protect living beings. Specialized industrial versions are optimized for maintaining the health of machinery and processes. Will Delsman NK Technologies Ground faults arise when current flows from an energized conductor to ground inadvertently. The return path of the fault current is through living beings or equipment touching the […]
Can a three-phase power supply operate from wye and delta ac inputs?
A few guidelines help clarify what three-phase input voltage best suits a particular large power system. TDK Lambda Technical Marketing AC-DC power supplies rated higher than 2.5 kW frequently have a three-phase ac input. In the U.S. the voltage can be 208/220 Vac or 480 Vac. In Europe, it is a “harmonized 400 Vac” which […]
Where fixed-ratio converters fit in high-power delivery systems
Fixed-ratio converters are often the best way of minimizing the electrical current sent over significant distances in the interest of better power efficiency. Phil Davies Vicor Corp. The vast majority of electromechanical or semiconductor loads require stable dc-dc voltage conversion and tight regulation to operate reliably. The dc-dc converters that perform this function are commonly […]
The try-before-you-buy route to energy efficient power design
Evaluation platforms help pick SiC components in power conversion circuits. Xuning Zhang, Levi Gant, Littelfuse, Inc. The quest for greener energy production and consumption has put a premium on high-efficiency power circuitry. In that regard, many modern power supplies and converters operate at much higher voltages that allow use of lower currents to minimize I2R […]
The 40-year battery pack
Not all primary batteries offer the low annual self-discharge rate needed for the lengthy lifespan of remote wireless devices consuming microamp-level currents. Sol Jacobs, Tadiran Batteries The vast majority of remote wireless devices are powered by primary (non-rechargeable) batteries that range from consumer-grade to industrial grade. Consumer-grade alkaline batteries deliver higher discharge rates of energy, […]
Electric locomotives and catenary power systems – Part 4: maintenance and corona
The high-speed all-electric railroad locomotive uses a catenary-wire system and pantograph power-transfer arrangement, which appears to violate good engineering practice and should not work. Still, it does, transferring hundreds of amps via a contact point moving at over 100 miles/hour. Part 3 looked at the pantograph and catenary power system in more detail. This part […]
Electric locomotives and catenary power systems – Part 3: power delivery
The high-speed all-electric railroad locomotive uses a catenary-wire system and pantograph power-transfer arrangement, which appears to violate good engineering practice and should not work. Still, it does, transferring hundreds of amps via a contact point moving at over 100 miles/hour. Part 2 of this article looked at power issues and numbers related to the electric […]
Electric locomotives and catenary power systems – Part 2: power needs
The high-speed all-electric railroad locomotive uses a catenary-wire system and pantograph power-transfer arrangement, which appears to violate good engineering practice and should not work. Still, it does, transferring hundreds of amps via a contact point moving at over 100 miles/hour. Part 1 looked at the basics of diesel-electric versus all-electric locomotives. This part looks at […]