For almost all usage today, flyback transformers are used in switched-mode power supplies as they are highly effective for both high voltage as well as low voltage supplies. Understanding why this type of transformer is the right choice for these applications starts with taking a closer look at the technology and the use of this component.
Originally flyback transformers were designed to be used with cathode ray tubes (CRT) to manage the movement on the horizontal plane of an electron beam within the tube itself. The input signal was fed into the flyback transformer, and the waveshape is changed, resulting in a change in the output current. They are still used today with CRT screen or display devices including televisions and computer monitors.
As with all transformers, there is a ferrous core surrounded by primary winding. However, unlike power supply transformers, there is also a secondary that is wound around the primary. The entire system is then covered by a ferrite frame to close the magnetic field lines within the transformer.
As a change occurs in current happens, and with the availability of the energy from the magnetic circuit in flyback transformers, it is possible to power additional components on the system or within the equipment with just one transformer. It is also possible to use a much smaller flyback design in compact applications without sacrificing the high voltage available to the system.
There are several different design features in many of the top models in flyback transformers on the market. One is to include extra windings within the transformer, providing a greater source of power and also allow for a much smaller design.
However, it is important to choose a well-designed model for these applications as the extra power is generated on the vertical sawtooth wave can result in a flash over the terminals. The extra windings will help to prevent this, making it a practical consideration.
Other options include the integration of rectifiers and voltage multiplier within the design of the flyback transformers. These act as failsafe mechanisms when used for displays. This means that if the circuitry fails, the transformer will automatically shut down, virtually blacking out the display. This will result in damaging the display or screen that would occur if the electron beam were to be immobile and targeted on one location of the display.