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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…

Voltage regulation of transformers 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…

A Flyback Transformer is a type of switching transformer that comes in two flavors, CCM (Continuous Conduction Mode) and DCM (Discontinuous Conduction Mode). The DCM version is the one we will develop here….   What is a DCM Flyback Transformer? The idea of the DCM flyback transformer is that the SEC current drops back to zero before the next…

The Department of Energy launched a poll:  Who is the greater inventor, Edison or Tesla? cettechnology.com Before getting to the poll results of Nikola Tesla vs. Thomas Edison, AC vs. DC, it is interesting to learn a little more about the inventors as individuals. About Thomas Edison We credit U.S-born Thomas Alva Edison with inventing…

The impedance of an inductor is proportional to its inductance and the frequency of the signal passing through it. Inductors, therefore, can act like low-pass filters, that is they allow low-frequency signals to pass through them, while they block higher frequency signals. A common mode choke inductor is a special type of filter with two…

Michael Faraday (1791-1867) was an English scientist whose many experiments contributed greatly to the understanding of electromagnetism, making him one of the most influential minds of the 19th century. Notably, Faraday began his career as a chemist. He wrote a manual of practical chemistry that reveals his mastery of the technical aspects of his art,…

COMMON MODE CHOKE / INDUCTOR DESIGN  The common mode choke is one of the many types of inductors. Common mode choke is usually used in a power supply to filter out noise from the incoming line voltage. Impedance is the most important aspect of a common mode choke. Impedance of an inductor is usually specified…

High Impedance Step Up Transformer Power Input – 48VAC Power Output – 107 VAC @ 280uA (30mVA)   The customer for this component had a guitar application where due to a lack of Earth grounding he was seeing a “phantom” voltage being induced elsewhere in his product.  Instead of ignoring this voltage he decided he…

New vending machine power supply design details: External type power supply Input – 110VAC – 240 VAC. Output – 24 VAC @ 3A – 4A (72W-96W). Input Connection – IEC C13 Male. Output Connection – Wire (Not terminated) (Optional) Notes: The power supply must have an A/C input line filter and voltage output regulation.  …