The Basics of a Switched-Mode Power Supply And SMPS Inductor

A switching-mode power supply or SMPS is used in a variety of different applications including in computers and electronics, as well as mobile phone charging systems, in cars and trucks and are heavily used in the telecommunication industry.

The use of SMPS technology is not new and precursors of the modern design can be found as far back as 1836 with the development of induction coils that actually utilized rudimentary types of switches. Different options in SMPs and SMPS inductor technologies continued to evolve and are still being modified for today’s electronics.

A Simple Explanation

The SMPS uses the SMPS inductor to convert electrical power from a mains power to the specific power requirements for the device or component. It is able to convert both the voltage and the current to allow the device to operate from the mains power source.

To accomplish this, the SMPS continually switches from low-dissipation and high-dissipation or full-on and full-off phases or states. This constant switching results in a lower overall energy use and a higher efficiency. In a well-designed system, there is ideally no dissipation of power, creating the ability to generate consistent, higher conversion of power through a smaller design.

The Importance of the Inductor

One of the key components in the efficiency of the SMPS is the SMPS inductor selected for the design. The inductor acts as the monitor control for the continual power supply out of the inductor regardless of any variations or changes in the power supply coming into the inductor. This prevents any changes in the power through the system when it is cycling from the switch being open to the switch being closed.

There are several factors to consider when choosing the inductor. The size of the ferromagnetic core will be important, as will the actual design of the component itself. The winding of the conductor coil around the core will have an impact, as well as the level at which the core saturates with current.

The cores of different types of inductors can be magnetically shielded or they can be unshielded. Generally, the unshielded cores offer a higher peak current level before saturation, which may be an important consideration when choosing based on performance requirements.

Different shapes including a drum, toroidal, planar, bead or a flat coil type of inductor. Each shape offers different features and is carefully designed for specific uses and applications.

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