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A switched mode power supply (SMPS) is a more modern and efficient take on the older power supplies known as linear supplies. LINEAR SUPPLIES Linear supplies would often take in line voltage, transform this via a low frequency silicon steel core transformer to a lower voltage. Then through rectification using diodes, and filtering using capacitors,…

When it comes to High voltage transformer design, it can be a bit tricky. When you’re trying to target a particular voltage one needs to account for things such as DCR losses in the windings. This is important when regulation is important. The following design procedure will get you close to the ballpark for your needs….

A super quiet EP13 size flyback transformer. Primary inductance is 4.31mH +/- 10%. Switching frequency is 60 KHz minimum. The input is rated at 120V. There are 2 outputs rated at 2.5V/600mA and an aux rated at 17V/20mA. The power rating is 3.4VA, but it could handle twice that at 6.8VA. The design reduces electrical…

The forward converter does appear similar to the flyback transformer, but it is actually very different. The forward converter transfers its energy instantly (transformer action) unlike the flyback which stores and then releases that stored energy to the SEC side… See below for a general schematic of this forward converter… As one can see there…

Most everything we use of convenience and need these days is electrically powered. Most often we have access to a source of voltage at one, or maybe two particular values. Unfortunately in many cases, the very items we use and need internally have components that do not run at the voltages available to us. Many…

In transformer design, there is an equation most of us are familiar with. This equation is known as the “transformer design equation”. This equation is applicable for inputs that are of most any voltage. The usual voltage forms are sinusoids as seen in lower frequency silicon steel type transformers such as UL Class 2 recognized…

One flavor of a high frequency switching transformer is known as a push-pull transformer. A push–pull transformer is a DC-to-DC switching transformer; it is often used to change a power supply’s DC voltage. These power supplies are known as switched-mode-power-supplies (SMPS). Older, linear power supplies often used low frequency, heavy silicon steel type transformers to…

In the spirit of the season, CET Technology would like to wish everyone Happy Holidays and a Happy New Year with our Custom Magnetics Song! Enjoy!   Twelve Days of CET Christmas On the first day of Christmas, CET sent to me A Toroidal Transformer for my radio and TV. On the second day of…

Predicting the final temperature of a part is not always an easy thing to do. It becomes a complex task for complex parts. We’re going to predict this final temperature for something simple, like air coil inductors. The mathematics found can “loosely” be applied to more complicated parts but certainly, the approach can be applied…

In order to design current sense transformers, you need to determine the DCR of the SEC, the inductance of the SEC, the SEC wire area/gauge to use, the magnetic area of the core, the excitation current, the % error of the CT and the desired output voltage for a given input current. Let’s start by…