Get ready to evaluate safety measures in a different way. JEFF SCHNABEL, CUI THE FAMILIAR 60950-1 AND 60065 SAFETY STANDARDS for information and communication technology (ICT) and audio-visual (AV) equipment are being phased out in 2020, in favor of a single, harmonized standard based on a more modern approach to safety and testing. OEMs must […]
FAQ
Transforming ac to dc without transformers
Substituting special capacitors for transformers helps realize ac-to-dc power supplies that are both efficient and compact. JEFF SORENSEN, HELIX SEMICONDUCTORS POWER SUPPLIES that convert ac to dc have been a part of nearly every electronics-based product since the popularization of the vacuum tube radio. While the voltage levels have changed, the conversion process has always […]
Get ready for thermal transistors
A Stanford-led engineering team has developed a way to not only manage heat but help route it away from delicate devices. Writing in Nature Communications, the researchers describe a nanoscale thermal transistor, something that researchers have been trying to develop for years. Previous thermal transistors proved too big, too slow and not sensitive enough for […]
Don’t let the LED blue light blues get you down
Despite claims by some websites to the contrary, LED bulbs don’t put out inordinate amounts of blue light. Leland Teschler, Executive Editor Take a look at some of the websites devoted to alternative medicine and you’ll likely come across headlines like, “The Dangers of LED & Blue Lights Will Blow Your Mind!” or, “LEDs: The […]
Why is it vital to include power factor in ac-dc efficiency measurements?
Ron Stull of CUI explains what power factor is, how it affects efficiency calculations and how it is measured With today’s concentration on energy savings, design engineers need to know with increasing accuracy what their ac-dc power converter efficiency is. Measuring the ratio of output power to input power is simple for dc-dc converters, but […]
Power-supply overvoltage protection, Part 2: Clamps
Part 1 of this FAQ discussed the context of overvoltage protection and crowbars which provide OVP. This part will look at clamps for OVP use. Q: What does the clamp do? A: A clamp conducts just-enough current to maintain the voltage across it at a safe, desired value when the transient is above the clamp’s […]
Power-supply overvoltage protection, Part 1: Crowbars
Engineers who deal with power supplies (as most eventually do) often see the circuit-protection terms “crowbar” and “clamp.” No, there are no references to items purchased at the local hardware store, but they are essential “hardware” elements, meaning autonomous circuit components and functions with no related software. They are used to provide protection to a […]
FAQ: Piezoelectric motors, Part 2: drive circuits
Unlike better-known electromagnetic motors, the widely used piezoelectric-based motor/actuator provides precise, repeatable linear motion over short distances, and requires a voltage drive rather than a current drive. Part 1 of this FAQ looked at the moving piezoelectric element of the actuator. Part 2 looks at their drive requirements, which are very different than those of […]
FAQ: Piezoelectric motors, Part 1: actuators
Unlike better-known electromagnetic motors, the widely used piezoelectric-based motor/actuator provides precise, repeatable linear motion over short distances, and requires a voltage drive rather than a current drive. When we think “motor”, we usually think of rotating motion or perhaps a special “linear motor” which is a rotary motor which has been rolled out flat. To […]
Optocouplers, Part 2: Parameters and applications
Part 1 of this FAQ explored the basics of the optocoupler. This part looks at key parameters and some application examples. Q: What are the primary factors used when assessing an optocoupler? A: While there are many important factors, there are several which are noteworthy: isolation, current-transfer ratio (CTR), linearity (for analog use), and speed. […]
