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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…

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…

In order to design a current sense transformer 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…

Transformer voltage regulation for no load and full load voltages. So you’ve chosen a bobbin, wire, PRI turns, etc… now you want to spec an output voltage under LOADED conditions and determine the SEC turns needed to meet those voltages… Your output voltage drops when the SEC is LOADED compared when it’s at NO LOAD….

In general, the primary and secondary windings in a transformer possess the same amount of inductance. This means that there is equal voltage and current levels in both circuits. There are circumstances, however, when voltages don’t match. For example, imagine that your electricity runs at 220 volts, but you have a 120V device, which is…

Who Invented the Inductor? Use of transformers and inductors in the electrical realm is such common practice that it’s hard to imagine a world without these devices. When the property of inductance was discovered in the 1830s by Joseph Henry and Michael Faraday (separately and on different continents), technology was revolutionized. Inductance was first found…