Most of today’s electronic devices us an SMPS or a switch-mode power supply. These devices complete specific duty cycles, or switch on and off, to allow a consistent supply of DC power to components on the other side the SMPS transformer.
There are two different types of SMPS and SMPS transformer options. One is the DC to DC transformers or converters. These are used in any battery powered type of electronics. These transformers are used to actually increase or decrease the current and voltage from the power source to allow a consistent required current and voltage output on the other side of the transformer.
The transformer itself is designed with winding, or wires that encircle the core. This core can be rectangular, square or toroidal, which is a donut shape. Each winding on the transformer, including the primary and secondary windings, can all be used to generate more than one output that is different and isolated from all others. In this way it is essential in stepping up or stepping down voltage based on the number of windings and the requirements of the outputs will power.
AC to DC
Many electronics, such as a desktop computer or an audio system are powered through mains power. In these types of situations, the SMPS transformer will convert that power from the wall outlet into the consistent DC power required by the components.
In most cases, a transformer will be used to handle this conversion, but in some equipment, there may be the need for both a transformer as well as a rectifier circuit. It’s also possible to use just the rectifier circuit, so understanding the specific needs of the device will be critical.
Typically, to ensure the consistency of the voltage, the receiving circuit will be in front of the transformer. This will create the consistent and balanced DC output voltage for safe operation of the subsequent electronic component.
Design Considerations
Choosing the correct transformer for the SMPS is a factor of the type of circuit required. The three most common include the Flyback, Buck and Boost options. The Buck circuit is designed to filter or minimize any ripple or peak currents in the system.
The Boost and the Flyback circuits store and then discharge energy to create a consistent voltage. This is done through ramping up of the energy in the transformer when the switch is on and then discharge when the switch is off.
