Electronic Transformers

There are many types of transformers. What distinguishes an electronic transformer from other types of transformers?

Electronic transformers are simply transformers used in electronic applications.

This is a very broad definition; consequently there are many types of electronic transformers. Examples of types of electronic transformers include ( but not limited to ) power, pulse, instrument, current, switching ( or switch mode ), inverting, signal, step-up, step-down, impedance matching, high voltage and saturable. Some of the preceding types can be divided into more sub-types. Types of switching transformers include ( but not limited to ) flyback, “feed forward” converter ( also called “buck” ), and boost. Gate drive transformers and trigger transformers are types of pulse transformers ( depending on who you talk to). The “feed forward” type includes a “push-pull center-tap” and a “half bridge” configuration. It becomes apparent from the preceding type designations that the type designation of an electronic transformer is determined by its intended application. To learn more about a particular type, click on one of the available links for electronic transformer types.

Electronic transformers may be further described by their basic structure and/or construction style. Many current transformers are wound on toroidal cores; hence the transformer is referred to as a toroidal current transformer. Many transformer coils are wound on bobbins ( spools ) or tubes. The transformer core is inserted into and around the coil. These transformers may be referred to as “bobbin wound” or “tube wound” structures. There are many core shapes available; E, E-I, U, U-I, Pot, RM, PQ, EP, EFD, and others.

Electronic transformers may be further described by the methods of mounting and electrical terminations. Transformers mounted on printed circuit boards may be “pin-thru” or “surface mount”. Transformer windings are terminated to bobbin pins or surface mount pads. The pins or pads are then soldered to the printed circuit board. Some transformers have lead wires. These wires are often referred to as “flying leads”.

Electronic transformers may be used to supply power, transmit signals, establish voltage isolation between circuits, sense voltage and current levels, modify voltage and current levels, provide impedance matching, and filtering. Lightly loaded transformers may perform some “inductor-like” functions, such as storing energy and limiting current flow.

Do electronic transformers have any characteristics common to all electronic transformers? Not really. Most electronic transformers can easily be held in your hand, even in a child’s hand, but there are some too large to hold. Due to ever-higher operating frequencies, more electronic transformers are being made from ferrite core materials, but some specialized applications use other core materials.

Despite the many types of electronic transformers, their theory of operation does not differ. Electrical functions are usually similar but design characteristics can differ in certain ways. Some examples are; unipolar versus bipolar core utilization, saturating or not saturating, degree of energy storage, regulation, and transformer impedance.

Butler Winding can make ( and has made ) electronic transformers in a wide variety of shapes and sizes. This includes; various standard types of “core with bobbin” structures ( E, EP, EFD, PQ, POT, U and others ), toroids, and some custom designs. Our upper limits are 40 pounds of weight and 2 kilowatts of power. We have experience with foil windings, litz wire windings, and perfect layering. For toroids, we can ( and have done ) sector winding, progressive winding, bank winding, and progressive bank winding. Butler winding has a variety of winding machines, bobbin/tube and toroid. That includes two programmable automated machines and a taping machine for toroids. Butler winding has vacuum chamber(s) for vacuum impregnation and can also encapsulate. To ensure quality, Butler Winding purchased two programmable automated testing machines. Most of our production is 100% tested on these machines. For more information on Butler Winding’s capabilities, click on our “capabilities” link.