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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….

Flyback Transformers, a type of switching transformer, come in two flavors, CCM (Continuous Conduction Mode ) and DCM (Discontinuous Conduction Mode). The DCM version is the one we will develop here…. The idea of the DCM flyback switching transformer is that the SEC current drops back to zero before the next ON time for the PRI. Generally a…

The Department of Energy launched a poll:  Who is the greater inventor, Edison or Tesla? cettechnology.com Before getting to the poll results, it is interesting to learn a little more about the inventors as individuals.  We credit U.S-born Thomas Alva Edison with inventing the light bulb, but in point of fact a light bulb prototype…

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     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….

What is a planar transformer? Planar Transformer Illustration A planar transformer is essentially a transformer that uses flat windings, usually on a printed circuit board, instead of copper wire to form the coils.  The PCB construction creates a different form factor that offers some unique advantages and a few tradeoffs.  What are the advantages of…

Science Quotes cettechnology.com   Here is a collection of interesting and sometimes funny quotes from scientists and engineers such as Einstein, Edison, Tesla and others.  To pause the slide show, hover your mouse over the image.  You can also navigate back  or ahead by clicking the arrows on the left or right of the image. …