Power supplies are the backbone of any electronic system and play a major role in every piece of electronics equipment. The primary function of a power supply is to convert the AC voltage, coming into a plant or building, to a DC voltage, which is used by most electronic devices.
What type of power supply?
Power supplies fall into two major categories: linear and switching.
Linear power supplies are typically used in applications that require low noise or low power. They can often be bulky and inefficient, but their low noise characteristics and simple design make them a viable choice for audio, communications and low power consumer electronics.
Switching power supplies have superior efficiency and performance levels compared to linear supplies. A switch mode power supply regulates an output voltage with pulse width modulation, which creates high-frequency noise but provides a high efficiency rating in a small form factor. Switching power supplies are frequently used for industrial applications.
Power supplies can be further classified by their packaging. External AC power adapters, also known as ‘wall warts’ or ‘wall adapters’, are used in low power consumer electronics such as laptops. Bench power supplies are stand-alone desktop units for test and measurement during the design process.
Which supply for my application?
For industrial applications there are three further packaging types suited to different kinds of application: open frame power supplies, enclosed power supplies and DIN rail power supplies. These are most often switching power supplies because of their efficiency and small form factor.
Open frame power supplies feature a partial mechanical enclosure and are often built into machinery or other equipment. The components are placed on a compact circuit board and can be easily installed in devices with existing housings. Open frame power supplies are usually small in size, cost effective and easy to keep cool. The GXE600 series from TDK Lambda is an open-frame programmable switching power supply that boasts up to 95 per cent efficiency. This series is particularly suitable for medical, information technology and communications applications as it meets international product specific IEC standards.
Enclosed frame power supplies are covered on all sides by a casing. These supplies protect components from elements such as dust and moisture and are most often used in hazardous environments. Many models integrate fans to compensate for heating problems.
A closed frame power supply, the CCH600PS28 from XP Power offers a switching power supply with efficiency of 90 per cent. This supply is suitable for a range of industrial applications as well as military COTS applications, as it meets military standards MIL-STD-461 EMC and MIL-STD-810 related to shock and vibration.
DIN rails provide the final option for securely attaching electrical and industrial control products, offering a cost-effective solution that also saves space by allowing for tight configurations. DIN rail supplies simply snap or slide into place on the rail. They are frequently used in control panels and electrical cabinets and are typically certified to UL standards. TDK-Lambda’s DRB50 series DIN rail power supply has a stated efficiency of up to 91 per cent. This supply is typically enclosed in control panels where it can be isolated from the industrial environment making it suitable for industrial and hazardous settings.
Choosing the correct power supply is essential to ensure electronics products run smoothly and reliably. Whether looking to use linear or switching power supplies, external AC power adapters, or open frame, enclosed or DIN rail power supplies, consider how each can benefit your project.