As discussed in Parts 1 & 2 of this FAQ series, RF transformers are complex devices and include parasitic resistances, inductances, and capacitances, which are non-linear and complex effects that compromise performance. Several fabrication methods including core-and-wire, low-temperature cofired ceramics (LTCC), and transmission line topologies have been developed to mitigate the impact of the various […]
FAQ
RF transformer fabrication – Making the best of a non-ideal situation (Part 2)
As discussed in part 1 of this series, physical RF transformers are non-ideal devices and include parasitic resistances, inductances, and capacitances, which are non-linear and complex effects that compromise performance. Several fabrication methods have been developed to mitigate the impact of the various parasitics and help to optimize RF transformer characteristics for the needs of […]
Dealing with non-ideal transformers — basic RF transformer theory of operation
When current goes through the primary winding of a theoretical (ideal) transformer, it generates a magnetic field which induces a voltage across the secondary winding. Connecting a load to the secondary causes an AC current to flow in the load. However, a physical transformer is far from ideal and includes parasitic resistances, inductances, and capacitances, […]
Design considerations for PoE
by Rich Fry, Director ICT, TDK Corporation of America The adoption of Power over Ethernet (PoE) in various applications is growing significantly, largely due to the added benefit it can provide for both the designer and end users: Fewer cords at workstations lower labor costs, and the ability to run an Ethernet LAN cable that […]
When it comes to UV-C LED lights, buyer beware
During the coronavirus pandemic, there’s been a lot of interest in using germicidal lamps to disinfect surfaces rather than hosing everything down with bleach or disinfectant. Lamps are a little easier to work with when you’ve got things like knobs, buttons, and slider controls on test instruments that may not do well when doused with […]
Comparing magnetic cores for power inductors
It is helpful to know how the material properties and geometries of magnetic cores affect the ability of inductors to store energy or filter current. There can be a mystique surrounding the specs of magnetic cores used in power inductors, due partly to the fact that magnetic materials may not be well characterized for handling […]
Killing Covid-19 with UV-C LEDs
Yes, light in the UV-C part of the spectrum will destroy the virus. Here are the basics and a few myths surrounding these light emissions. For those of us still working, it can be a bit unsettling to ponder whether the surfaces we touch harbor a few virions left over from someone infected with Covid-19. […]
Hot topic: Electric vehicle components get more sophisticated thermal models
The high electrical currents of fast charging are forcing designers to invent standard techniques for predictably modeling heat and cooling. Dr. Michael Ludwig, T&C Core Technologies, TE Connectivity The only way electric vehicles (EVs) will ever catch on is if consumers can charge them up quickly. Consequently, manufacturers are developing high-power charging (HPC) schemes which […]
Myth busted: No, LEDs don’t get 50% dimmer after a year
A one-year burn-in test helps refute a small piece of fake news about LED bulbs. We’ve torn down a number of LED bulbs over the years to analyze their content and design strategies. But when we published some of our findings a little over a year ago, we got this missive in the comment section: […]
Heat shrink tubing, Part 2: Extensions
Although we take it for granted, versatile and widely used heat shrink tubing is the result of advanced material science, and is available in a broad range of varieties and options. Part 1 of this FAQ looked at the basics of HST and its history. This part looks at the many variations and standard options […]