A Switch Mode Power Supply, or SMPS, is a power supply that uses a switching regulator in the conversion of electrical power. A SMPS is often called a Switcher too. It gets power from the grid (the mains) and transfers it to the appliance (example a PC) while converting current and voltage at the same time. Switchers are preferred compared to linear transformers when efficiency, size and weight are needed.

Compared to a linear power supply unit (PSU), a SMPS consumes less energy and are far more efficient. They are able to convert electric current without the use of a transformer. Voltage can be regulated via the use of electronic circuitry. It uses a pass transistor that switches on and off very quickly without the need to dissipate excess voltage. Aside from this, switching power supply units are smaller and lighter compared to linear PSUs.

Aside from the above mentioned advantages a SMPS wastes very little power in the form of heat. Incoming AC power is converted to amplifier output power. Most switching power supplies also come with safety features. A crowbar unit is used to protect your electronic device from fluctuating current, at the same time it works to limit current. Let us say there is high power being drawn from the mains, the switcher can detect this current and switch itself off preventing any damage to your electronic device.

Switching mode power supply units are also very versatile “little” tools. Unlike its cousins, the linear transformers which can only step down an input, SMPS solves the problem of converting standard voltage into a specific output voltage. In other words they can either step up, step down, invert or even step up and down the input voltage. Most modern switchers are also designed with customization in mind. This allows the user to choose topologies for various levels of integration. In other words, there is no need to bring different SMPS for different uses. It can be customized on-the-fly for the user’s specific need.

One common use of a SMPS can be found on personal computers. The PSUs of computers are normally SMPS types. These have universal inputs which means they are able to accept electrical power from most regions in the world. Mobile phone chargers have also switched from linear power supplies to SMPS. The switch is most probably due to a great demand in phone chargers that are more efficient, not to mention, more practical for use wherever you are in the world. The trend for TV sets that have switched to SMPS for regulation of current is growing too. It may not be long before all personal and household electronic gadgets are using SMPS.

In conclusion, switching mode power supply units are energy efficient when it comes to converting voltages from the wall socket to the appliance. Because it is lightweight and has a smaller size, it is more convenient to lug around which makes it perfect for travel. The built-in safety features of a SMPS protects electronic devices from fluctuating electrical currencies, a function invaluable to the gadget-heavy style of today's electronic world.