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Lines of magnetic flux are created when a current flows through a conductor. They can transport energy from one winding to another usually though a permeable core of some kind. The amount of flux per area is known as flux density. Transformer and inductor cores have finite flux densities. That is, they can only handle so much flux over…

In many cases introducing an air gap can be of great use. Often people/engineers may think that introducing an air gap increases the maximum flux density a core can handle. This is actually not true The core has a maximum flux density that is set by the material properties of that core, not by an…

Here at CET, we do custom transformer and inductor solutions every day. One such part was a high current custom choke desired by a customer of ours. The design of this part actually went through a couple of iterations. Initially, we designed for performance keeping cost in mind. Our solution was a performance success, but the…

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.   Design Procedure: The following high voltage transformer design procedure will get you close to…

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. A forward converter transformer transfers its energy instantly (transformer action), unlike the flyback which stores and then releases that stored energy to the SEC side…   General Schematic for a Forward Converter See below for a general schematic of…

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…

When it comes to transformer design, there is an equation most of us are familiar with. This transformer equation is known as the “transformer design equation”. This transformer 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…

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 step…