Industrial power supplies deliver 2500W in slim-line 1U high format

LA2882 - RFE2500 Series

TDK Corporation announces the introduction of the RFE2500 series of AC-DC power supplies. Rated at up to 2500W output power, the units are available in three output voltages, 12V, 24V and 48V. Featuring screw terminal and bus-bar connections, this very compact series does not require an additional plug-in rack or backplane making it ideal for space-constrained industrial, communications and test & measurement applications.

Operating from a wide-range input of 85 to 265Vac, the RFE series has operating efficiencies of 90 to 93% minimising internal heating and reducing power consumption. Up to 8 units can be connected in parallel for additional power or to provide a redundant power system. Internal ORing FETs and single wire current share are included as standard.

The units will operate in ambient temperatures of -10 to +70ºC with applicable derating above 50ºC. The outputs are adjustable by up to 20% using either the front panel trim pot, an external 0 – 5V signal or an external 1k potentiometer. The RFE is cooled by two internal temperature controlled fans to reduce acoustic noise at lower temperatures and loading conditions. Overall case dimensions are 107 x 41 x 345mm (W x H x D), and the weight is just 2.5kg.

As standard the RFE has AC Fail and DC Good signals, remote on/off, a 12V 0.5A auxiliary output, remote sense and LED indicator lights. An optional PMBus™ interface allows engineers to remotely monitor output voltage, output current and the internal ambient temperature in addition to status information. The output voltage, overcurrent limit and remote on/off can also be programmed.

The units are safety certified to IEC/EN/US 60950-1 with CE marking for the Low Voltage and RoHS2 Directives. They also comply with EN 55022-B conducted emissions (Class A radiated), and meet the EN 61000-3-2 harmonics and IEC 61000-4 immunity standards.

For more information about the full range of TDK-Lambda RFE2500 series of AC-DC power supplies, please call TDK-Lambda directly on +44 (0)1271 856600 or visit the TDK-Lambda website at:


Introducing the iJA 35A non-isolated SMT Point of Load with PMBus™

With PMBusTM compliance, the iJA series of non-isolated POL DC-DC converters provides excellent flexibility and the ability for customisation. Accepting an 8 to 14Vdc input, the product can deliver up to 35A with an adjustable output voltage of 0.6 to 3.3Vdc. Designed to drive CPUs, FPGAs and ASICs, these POLs feature digital adaptive control to accommodate a wide range of external load capacitance with great stability, even without the use of external loop components.

To watch the video, which introduces the iJA series, please click here.

Click here to read more about the full range of DC-DC converters, or click here for the product page:

If you have a question you’d like to ask TDK-Lambda, please feel free to use the online FAQ form and we’ll get back to you with an answer to your question as soon as possible.


Testing Transportation Refrigeration Units


To ensure refrigeration reliability in transportation applications, each unit must be thoroughly tested to avoid expensive cargo losses. TDK-Lambda’s 5-year warranty RWS-B 600W power supply is used to supply the 12Vdc input needed during the test process by a producer of high quality refrigeration units. The /CO2 option was specified to help protect the power supply printed circuit boards from ingress of any contaminants. Also, the customer preferred the additional protection the RWS600B galvanized sheet metal provided against corrosion. Local support and relationship also helped win the opportunity.


Satellite Communications


For remote or offshore locations, satellite communication is an ideal and reliable way to transfer data and connect facilities or equipment together. Transmission channel up-time is enhanced as third party infrastructure is avoided. A provider of satellite communications designed in TDK-Lambda’s iQE series of 12V output DC-DC converters. The wide-range 18 – 60V input version was used to allow operation with either 24V or 48V battery back-up. The 5-year warranty RWS150B AC-DC power supply is also being used where DC input is not required. Support was provided throughout the project by the local sales team.


Integrated Process Plant Telecommunication Systems


Telecom equipment is often isolated from the manufacturing process plant control system. The revolution of Industry 4.0 is changing the way goods are built and processed, requiring full integration of all the communication networks. A major provider of process control integrated systems is using TDK-Lambda’s iEA high efficiency DC-DC converter to deliver 28V power with minimal airflow. Local support was welcomed by the customer during the development.


DNV GL and how this applies to power supplies

Like UL (Underwriter’s Laboratories), DNV GL’s heritage stems from insurance. DNV and GL were originally formed in 1860s to evaluate the quality of ships. That has since been expanded to include the vast array of electronics systems now used in maritime on/offshore applications.

Power supplies are used extensively to provide regulated voltages to drive motors, relays and power those electronic systems. Most manufacturers of power supplies are already familiar with getting IEC 60950-1 certification for use in information technology equipment. DNV GL certification, or Type Approval as it is referred to, has some differences:
An audit is carried out at the manufacturer’s factory, similar to that for ISO9001, which is valid for five years. Follow up visits are made after that.

Product assessment is made to the test standard “Guidelines for the Performance of Type Approvals – Test Requirements for Electrical / Electronic Equipment and Systems (VI-7-2)”. This report format is similar to that of an IEC 60950-1 CB report, and includes conducted and radiated EMC results.

Two levels of approval are possible which determines the type of application the power supply can be used in: Zone 1 – Bridge and open deck and Zone 2 – General power distribution. The limits on radiated emissions and conducted emissions are different to EN 55022, with Zone 1 more stringent.

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Immunity tests are performed using IEC 61000-4 as a basis.

Products also are defined to environmental categories A through H which states operating conditions like temperature, humidity and vibration.

Upon successful completion of the tests, the power supply can then be labelled with the GL Mark.

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A power supply like TDK-Lambda’s DRF/HL series of 120W to 480W DIN Rail power supplies which is approved to Environmental Category C, Zone 2, could be used in a Zone 1 application provided it is mounted in a minimum IP54 rated enclosure with an additional input filter. Coated printed circuit boards in the DRF/HL provide additional protection against moisture.
The DRF/HL series is also ATEX and IEC Ex certified for explosive atmospheres, certified to IEC 60950-1 and is backed by a five year warranty.


Endoscope LED Light Source


Endoscopes depend on high quality light to give optimum imaging results. Compared to XENON bulbs, LED light sources offer very low maintenance, low energy consumption and instant full illumination. One recognised market leader chose TDK-Lambda’s EFE300M 300W medically certified power supply for their new high reliability LED light source. Product quality and available documentation were cited as the reason for the choice, in addition to local sales support.


High efficiency 3” x 5” medical power supply delivers 250W

LA3957 - CUS200M

TDK Corporation announces the introduction of the TDK-Lambda CUS200M series of AC-DC power supplies. With efficiencies up to 94%, the series can deliver 200W with convection cooling or up to 250W with 1.5m/s airflow. The units, packaged in the industry standard 3” x 5” footprint, have both medical and ITE certification to the IEC 60601-1 and IEC 60950-1 regulatory standards. The CUS200M is ideally suited for applications where audible noise cannot be tolerated, including hospital, dental, broadcast and professional audio equipment.

The power supplies operate from an 85 to 265Vac input and are available with 12V, 18V, 24V or 48V nominal outputs. The CUS200M has a stand-by power consumption of less than 0.5W, and the product’s high efficiency allows it to operate conservatively at full power in
-20˚C to +50˚C ambient temperatures, or up to +70˚C with derating. As standard, the series has remote on/off, an isolated power good signal and a 5V standby output capable of supplying 0.6A convection cooled, or 1A with forced air cooling.

Input to output isolation is 4,000Vac (2 x MOPPs), 2,000Vac (1 x MOPP) from input to ground and 1,500Vac (1 x MOPP) output to ground, making it suitable for BF rated applications. Safety certifications include IEC/EN 60601-1, ANSI/AAMI ES 60601-1 and IEC/EN/US 60950-1 with CE marking for the Low Voltage and RoHS2 Directives. The units also comply with EN 55011-B, EN 55022-B and FCC Class B for conducted and radiated emissions (200W output power), and meet the IEC 61000-4 immunity standards.

For more information about the full range of TDK-Lambda CUS200M series of AC-DC power supplies, please call TDK-Lambda directly on +44 (0)1271 856600 or visit the TDK-Lambda website at:


ATEX and how this applies to power supplies

The acronym ATEX, derived from the French phrase “ATmosphere EXplosible”, was initially introduced in the European Union to facilitate the free movement of goods and services of equipment used in hazardous environments. The resulting ATEX Directive removed the need to test and document a product for each EU country by harmonising the way different hazardous explosive environments are classified across all industries.

The ATEX 95 equipment Directive 94/9/EC, which became mandatory in July 2003, covers a wide range of equipment and protection systems for use where a potentially explosive atmosphere may be present.

Power supplies are used extensively to provide regulated voltages to drive motors, relays and power electronic controls. As power supplies produce heat and contain high voltages or currents that can cause sparks, it is advisable to select a product that conforms to this Directive for use in explosive environments.

For power supplies, compliance is determined through the application of one or more of the EN 60079 group of standards for Explosive atmospheres. With coated printed circuit boards TDK-Lambda’s DRF HL series DIN rail mount power supplies comply with the requirements of EN60079- 0: Equipment – Part 0: General requirements and EN 60079-15: Explosive atmospheres – Part 15: Equipment protection by type of protection ‘n’, which is then referenced by the manufacturer on the Declaration of Conformity to apply the CE mark.


As the Declaration of Conformity is self-declared, an external test house is commonly used to prepare a test report and certificate. Those documents will specify the Ex marking on the product and, if an “X” follows the certificate number, any conditions for safe use.

EX Mark

For TDK-Lambda’s DRF120-24-1/HL DIN rail mount power supply, the certificate states the ratings (ambient temperature, input and output voltage and current), that they are intended for use in hazardous systems in Zone 2, gas group IIC, and should be mounted in an enclosure with a degree of ingress protection to at least IP54. The Ex marking of the product is as follows:

The Ex mark means it’s been tested by a notified body
II is the equipment group (gas surface industries)
3G is the equipment category (zone 2)
Ex is the Explosion protection
nA is protection type (non-sparking)(prevention)
nC is the protection type (non-sparking)(containment)
IIC is the gas group
T4 is the temperature class (hottest surface or part)
Gc is the Equipment Protection Level (Gas)

As well as being ATEX (and IEC Ex) certified, the DRF HL Series complies with class B conducted and radiated emissions and has UL/EN 60950-1 safety certifications. All models meet EN61000-4-2, -3, -4, -5, -6, -8, -11 (immunity) and EN61000-3-2 (harmonic correction) standards, backed by a five-year warranty.

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Points to consider when selecting external power supplies for home healthcare applications

With life expectancy rates rising and the associated costs of patient care soaring, medical providers are looking at ways of reducing costs while still maintaining a high level of treatment. With this, the solution of treating and monitoring patients in their homes is gaining prominence. Secondly, due to medical advancements, many individuals with chronic diseases are living longer but are dependent on medical care. Lower costs for electronic equipment and a mainstream adoption of cellular and internet services now make moving healthcare from hospitals and clinics to the patient’s home viable. Already, non-clinical treatment of respiratory ailments is common through the use of infusion pumps, oxygen concentrators and positive airway pressure machines.

Home healthcare offers additional benefits to the patient, who now can be treated in the comfort and familiarity of their homes, avoiding long, stressful hospital stays. In the example of kidney dialysis, treatment is more effective when performed over a longer period of time, rather than with short, multiple visits to the healthcare provider’s facility. Haemodialysis, the cleaning and filtering blood, when performed daily for two to three hours, emulates the normal functions of healthy kidneys.

The medical regulators recognise that there are implications and unique risks associated with these home devices, and that these need to be assessed early in product development. In a hospital the environment is sterile and defined, with trained staff on hand during patient treatment. Once outside, potentially hazardous situations can arise. Inappropriate or incorrect use combined with the incompatibility of the environment can cause devices to malfunction, contributing to serious injury or even death. As a note, in the EU nursing homes are classed as “home”, rather in the United States where they are considered as “clinical”.

The international standard IEC 60601-1-11 – Part 1-11, lays down the general requirements for basic safety and essential performance of medical electrical equipment and medical electrical systems used in the home healthcare environment. This standard is also applicable to external AC-DC power supplies used to power those products.
Medically certified external AC-DC power supplies have been widely used for many years meeting relevant parts of the IEC 60601-1 standard. Their primary use though, has been inside hospitals and clinics. Certification for home use requires additional testing. This is primarily directed at the actual use of the product rather than electrical spacing, temperatures and identification of safety critical components.

In North America and Europe, it is estimated that less than half of the homes have reliable earth grounding. With a Class I product, an electrical fault would cause current to flow through a low impedance ground connection and trip a leakage breaker. With inadequate house wiring, this could lead to an electrical shock and have serious implications on a patient whose health could be in a weakened state. With a Class II, double insulated power supply; no ground connection is needed, eliminating the need for the equipment to be professionally, permanently installed.

Outside of a hospital environment, the external power supply could be subject to the ingress of water, either by rainfall or even a spilt drink. Two levels of ingress protection (IP) are considered for IEC 60601-1-11: IP21 (as a minimum) vertically dripping water, or IP22 (preferred) angled dripping water, equivalent to 3mm of rainfall a minute in accordance to IEC 60529. Dielectric voltage withstand tests are performed to ensure compliance. The IP rating is added to the power supply rating label.

Class B EMC is mandatory, avoiding interference to any household appliances. The tested AC input voltage is lower than regular power supply safety standards, down to -20%. Most external power supplies will meet this anyway as they will usually have wide range operability down to 90Vac.

Again due to home use, additional temperature and humidity testing is conducted. The mandated temperature range is -25 to +70 °C for storage, +5 to +40 °C for operating and 15 to 93% RH for humidity. Any deviation from this can be noted in the product installation manual.

The nature of using an external power supply in the home justifies the shock and vibration testing. Tests are conducted in accordance with IEC 60068-2-27:2008 and IEC 60068-2-64:2008. This is to ensure that the product will be reliable and basic safety and operational performance maintained.

Energy conservation standards are not covered by the IEC medical standard, and although regional regulation is in place for consumer equipment, medical power supplies have some degree of exemption. As of the publication of this article, it would be wise though to select a power supply with a level VI rating.

The additional testing and certification for IEC 60601-1-11 – Part 1-11 is not arduous. With the sometimes harsh nature of the home environment, coupled with the likelihood of physically weakened patients being at risk, compliance with the standard will become more common across the power supply industry.

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