If you’re integrating a switch mode power supply (SMPS) into a system, you expect good power efficiency. You also have to be sure you’re getting the most useful energy when drawing power from the AC main. To get the most of your AC power draw, you must also consider the power factor during your SMPS selection. Let’s discuss some of the basics of power factor and what you should look for in a switch mode power supply.
Power Factor Basics
As switch mode power supplies draw power from the grid, not all of that power can be used. The SMPS typically draws the AC input current in short, high-magnitude pulses. As a result, the current is out of phase with the voltage. Because of the variance, some of the main energy is displaced and unavailable for useful work. This condition is known as power factor — a ratio of the supply’s working power compared to its apparent power. Power factor is expressed as a decimal between 0 and 1.
Without maximum working power, the system must draw more power and incur the associated costs. Poor power factor can also create harmonic distortion that can damage equipment in the circuit. To avoid these situations, power supply manufacturers employ power factor correction (PFC) techniques to bring the supply’s power factor as close to 1, or unity, as possible. For low-power supplies, PFC typically involves smoothing out the short pulses using passive components to create a low-pass filter. Higher-power supplies use control circuitry or a regulator to harmonize the input voltage and current. For most applications, SMPS that achieve a power factor of 0.9 or higher are ideal.
Our new UIA700 Series 700-watt switching power supply is one such example. It comes with a power factor figure of greater than 0.9, making it appropriate for a wide range of industrial equipment. It accepts a wide 90 to 264V AC input for use globally, and its small size of 6.7 by 3.66 by 1.61 inches makes it ideal for space-constrained applications. And, you don’t have to choose between a high power factor and high efficiency, thanks to the UIA700’s 92-percent efficiency rating.
Additional features and specifications include:
- A remote ON/OFF function for energy savings.
- Standby: 5V at 1A.
- Chassis mount with terminal strip.
- UL/IEC/EN 62368 approval.
When specifying a SMPS, keep in mind that domestic and international regions have regulations that define local power factor or harmonics requirements.
Optimize Power and Space
Switch mode power supplies with a PFC function make the best use of the main power, and those with a power factor of 0.9 or better are preferred for most applications. Our UIA700 Series switching power supply combines a high power factor, high efficiency and small size to achieve optimal AC power for a broad range of industrial applications.
For more information about Daburn Electronics’ Polytron Devices UIA700 Series switching power supply, visit our product page