Compact & Certified PCB Mounted AC/DC Power Supplies

Modern electronic assemblies are often designed to be very power efficient, so that they only draw a few watts of power. For such applications, RECOM has developed a wide range of Class II isolation 1W-10W AC/DC power supply modules for PCB mounting, designed to withstand PCB wave soldering processes. These board mount AC/DC converters are complete power supplies, requiring no external components to fully meet safety and EMC regulations without an earth connection. They are offered with a 85VAC to 264VAC or 305VAC universal input voltage range for worldwide use. Notably, the RAC05-K/480 series can additionally operate from phase-to-phase with its extended 85VAC to 528VAC input range.

Opting for PCB mount AC/DC power supplies offers key design and manufacturing advantages. Their compact form factor saves board space, contributing to smaller end-products. Direct board mounting simplifies assembly, reduces wiring, and can enhance system reliability. Modules designed for wave soldering also boost manufacturing efficiency for these low power AC/DC solutions.

RECOM uses the latest advances in switching controllers, topologies, and components to create power supplies with up to double the power density than previously possible without sacrificing safety, reliability, efficiency, or performance. The majority of AC/DC power supplies from RECOM are internationally certified to UL/IEC/EN standards for industrial (EN/IEC/UL 62368-1), measurement, control, and laboratory (EN/IEC/UL 61010-1), and household (EN/IEC/UL 60335-1) applications, with CB Reports available. This comprehensive certification makes them suitable for a broad spectrum of applications including industrial controls, test and measurement equipment, and building automation systems.

When selecting a low power AC/DC module, consider these critical features beyond certifications and input ranges:

• Low Standby Power: Crucial for energy-efficient, "always-on" applications to meet eco-design standards.
• Integrated Protections: Essential safeguards like overcurrent, short-circuit, and over-temperature protection for the module and load.
• Robust Packaging: Encapsulated board mount AC/DC power units offer durability against environmental factors like dust and moisture.
• Class II Isolation: This design simplifies installation (no earth connection) and enhances safety where grounding is challenging.

These versatile 1W to 10W AC/DC power supply modules suit numerous applications. They are commonly used in industrial controls (e.g., sensors, local MCUs), test and measurement equipment (portable/benchtop devices), and building automation systems (smart controls, security). Additionally, these universal input AC/DC modules power many Internet of Things (IoT) devices, smart home/office systems, and serve as auxiliary power sources in larger equipment.

While three-phase AC supplies are used for high-power loads, there is often a need to generate low-power auxiliary DC rails from the same source. This is typically derived from line-to-neutral at 400VAC, or line-to-line at 480VAC or 277VAC nominal. This requirement can be met efficiently and conveniently using AC/DC modules with an input range of 85VAC to 528VAC, accommodating the highest nominal voltages and tolerances. The ability to operate down to 85VAC also ensures compatibility with single-phase AC supplies as low as 100VAC nominal.

AC/DC converters connected to three-phase supplies must typically withstand higher voltage transients than those connected to single-phase AC within buildings. As a result, these units should be rated at least Over-Voltage Category III (OVC III) minimum. Additionally, AC/DC modules in three-phase applications are often installed in harsh environments and must be robust — capable of operating at high temperatures and ideally encapsulated to meet Pollution Degree 3 (PD3) standards. Compliance with EMC requirements for both emissions and immunity is essential, along with adherence to no-load power consumption limits. RECOM offers suitable modules rated at 5W, 15W, and 25W in a through-hole PCB mount format.

PCB-mount through-hole converters from RECOM feature 85–528VAC input ranges, supporting global single-phase and three-phase line-to-neutral or line-to-line voltages up to 480VAC plus tolerances.