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Choose an External Power Supply That Takes Efficiency to the Highest Level

IP1019 IMAGE 1External power supplies (EPS) have come a long way to raise efficiency in recent years. During the 1990s, the number of electronic devices grew rapidly and in turn, so did the need for adapters for things like laptops, cell phones and other consumer electronics. Not only were efficiencies well below 60 percent, external power supplies stayed connected to the mains power when the devices were turned off. Together, “no-load” power consumption and low efficiency place high demands on energy grids and contribute to greenhouse gas emissions.

After some unsettling predictions concerning EPS’ potential burden on energy consumption, recent years have seen EPS efficiency regulations from California, the U.S. government and several international governments. In 2007, the U.S. Congress passed the Energy Independent Security Act (EISA) to harmonize efficiency standards in the U.S., starting with the Level IV standard and followed by Level V. The most recent EISA standard — the Department of Energy (DOE)-implemented Level VI — drastically reduced no-load power dissipation limits versus the preceding DOE standards. If your end product includes an EPS, make sure it complies to the latest U.S. and international efficiency standards in order to access your intended market.

The DoE Level VI Standard

DOE Level VI became mandatory in 2016. The standard applies to all direct and indirect operation EPSs including lower-voltage DC-output, multiple-output voltage EPSs and those with output power above 250 watts. For external power supplies that range from one to ≤49 watts, it limits no-load power consumption to 0.100 watts. Units in the 49- to 250 watt range cannot exceed 0.210 watts of power.

Polytron Devices recently introduced two AC/DC external power supplies that meet the efficiency requirements of DOE Level VI as well as Europe’s proposed Code of Conduct (CoC) Tier 2 efficiency standards. IP1019 and MIP1019 Series single-voltage power supplies are offered with output power ranging from 15 to 24 watts and accept 100- to 240-volt input voltages. The 2.46 by 1.61 by 1.34-inch adapters feature:

  • an interchangeable plug.
  • built-in over voltage and short circuit protection.
  • <30,000 hours MTBF.

The IP1019 targets industrial applications, and the MIP1019 carries UL/CUL 60601-1, EN60601-1, UEC60601 3rd edition as well as FCC, CE and CB medical safety approvals.

Stay Current With Efficiency Standards

Customers and regulators worldwide now demand power supplies that save energy and minimize greenhouse gas emissions. When selecting an external AC/DC power supply, consult with the supplier to see if the unit meets the latest efficiency standards. Polytron Devices’ IP1019 and MIP1019 meet both DOE Level VI and CoC Tier 2 criteria so you can be sure your product complies with these important regulations.

For more information about Polytron Devices’ Level VI-compliant IP1019 and MIP1019 external power supplies, visit our product pages.


IP1019 SeriesMIP1019 Series

Railway Applications Demand DC/DC Converters Meet Fire Safety Standards

SWBR6Railway manufacturers and regulators continually strive to improve fire safety. Minimizing smoke density in the event of a train fire is critical to safe evacuation or to allow rescuers to reach stranded passengers. Because the various electronic systems that ensure reliable train operation and passenger comfort are potential fire sources, designers must make sure that the materials and components that go inside railway electronics meet EN45545 fire safety standards.

What is EN45545?
EN45545 is a European railway safety requirement that ensures the use of materials that limit fire development and produce low levels of smoke and toxic fumes. Part Two of EN45545 consists of various requirement sets that define the test methods and criteria for assessing materials’ fire behavior. For example, EN45545-2 requirement sets R24 and R25 cover printed circuit boards, and set R26 applies to small electrical products. Trains built after March 2016 must be in compliance with EN45545, so be sure the DC/DC converters and other components you choose for railway applications satisfy the standard.

Polytron Devices offers DC/DC converters that have been tested and approved to meet relevant railway standards. Its SWBR3 3-Watt and SWBR6 6-Watt Series DC/DC converters with 4:1 wide input range feature high efficiency up to 83 percent, low ripple and noise and 3,000V DC input to output isolation – all in an 0.86 x 0.36 x 0.44-inch miniature SIP package. In addition to satisfying the EN45545-2 standard, it also meets EN50155 which covers various challenging railway conditions and the EN55032 standard for EMC in information technology equipment used in railway applications. Additional features and specifications include:

  • Remote ON/OFF control.
  • Low standby power.
  • Short circuit and over current protection.
  • UL, CB, CE Marked.

Choose a DC/DC Converter With Proven Fire Performance
Efforts to improve fire safety for railway passengers and crews are always evolving, and EN45545 is setting benchmarks for the railway industry. EN45545 also creates challenges for engineers who must be certain their designs can be applied to railways in Europe and other regions with stringent railway standards. When selecting DC/DC converters for railway applications, look for devices that carry EN45545-2 certification. SWBR3 and SWBR6 Series DC/DC converters from Polytron Devices have been tested and approved to EN45545-2 so designers can be sure they can be incorporated into railway applications that demand components with optimal fire performance characteristics.

For more information about SWBR3 and SWBR6 Series DC/DC converters for railway applications, visit the product pages: SWBR3,  SWBR6.


Make Sure You Have the Right Power Supply for the Altitude

When you choose an industrial power supply, it's important to consider whether the unit will withstand the conditions it might encounter. Threats like extreme temperatures, dust, liquids, shock and vibration quickly come to mind in industrial applications. However, you would be remiss if you don’t also ask yourself about the altitude at which the supply will operate. Power components behave differently at higher altitudes than at sea level.

Close to sea level, air is a good insulator inside a power supply. But at thousands of meters in altitude, barometric pressure is lower and air loses some of its insulating properties — its dielectric strength. Thin air with low dielectric strength can cause unintended breakdown voltage or arcing, which can present safety concerns for personnel as well as risk of equipment failure. Higher altitude also diminishes the cooling action of air, making heat removal difficult.

How Power Supplies Account for Altitude
Be sure to ask your power supply vendor or check the datasheet to make sure the unit is right for its operating altitude. Power supply manufacturers address altitude by how they separate their internal components. That means they allow for additional clearance — the shortest distance between components through the air, and creepage — the shortest distance along an insulating material (such as the circuit board) common to two parts. The higher the altitude, the greater the separation required between components. In addition to checking the operating altitude on the datasheet, verify that it meets the regulatory standards for altitude in its intended country and industry, such as medical.

Polytron Devices’ KUI30 Series is a good example of an industrial power supply for high elevations. These universal input, 30-W AC/DC power supplies with a wide-input voltage range of 85 to 264V DC have been designed for an operating altitude of 5,000 meters and provide 3,000V AC of reinforced insulation. Available in open-frame design (KUIO30) and encapsulated (KUI30) versions, these Protection Class II supplies also feature:

  • Up to 91.5 percent efficiency.
  • An adjustable output voltage.
  • Low leakage current.
  • Low standby power.
  • UL/EN/IEC 60950-1 approval.
  • Over current, over voltage and short circuit protection.

Don’t Overlook Altitude
Dirt, shock, vibration and temperature are all important conditions to consider when selecting an industrial power supply. One additional factor — operating altitude — should not be overlooked. Polytron Devices’ KUI30 AC/DC power supplies account for thinner air and offer several protective features that make them desirable for industrial applications where high-altitude operation is a concern.

For more information about Polytron Devices’ KUI30 Series AC/DC power supplies, visit the product page.


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Select DC/DC Converters That Minimize Patient Shock Risks

When selecting DC/DC converters for medical applications, it’s important to remember that power products typically used in medical designs can potentially harm a patient. Power products that meet IEC 60601 medical standards are designed with patient protection in mind. IEC 60601, Part I contains specifications and values that can prevent patients from incurring accidental electrical shock. Two of the three main specifications — isolation voltage, and creepage or clearance distances — are covered here.

In addition to considering power products that offer isolation protection between the electrical circuits and equipment that may contact the device, designers should also be aware of a third specification: Leakage currents, also known as touch currents. They’re the leakage paths from an enclosure that may contact a patient or operator. Because medical patients are often in a weakened state, even a small amount of leakage current can cause them harm. The standard specifies maximum levels of 100 µA for normal operation and 500 µA for a single fault condition.

DC/DC Converter Family Offers Exceptional Leakage Current Characteristics and Satisfies EN60601-1

One particularly good example of a DC/DC converter series that meets IEC 60601, Part 1 is Polytron Devices’ recently introduced MTWA2 and MTWA4 2-watt and 3.5-watt devices. Not only do these DC/DC converters with 2:1 input range exhibit a low leakage current of 2 µA, they offer 5000V AC input to output isolation and the highest level of patient protection — 2 x MOPP. Thanks to process efficiencies that result in a lower cost versus previous DC/DC converters, this series is a desirable option for portable devices with low wattage requirements.

The MTWA2 and MTWA4 Series DC/DC converters with 2:1 input range are both available in 4:1 input versions — MTWB2 (2 watts) and MTWB4 (3.5 watts), respectively. Additional features and specifications include:

  • 2:1 wide input voltage range: 4.5V to 12V DC input; 9V to 18V DC and 18V to 36V DC and 36V to 75V DC.
  • Efficiency as high as 82 percent.
  • Over voltage, short circuit and under voltage protection.
  • Availability in miniature DIP16 and SMD16 packages.
  • RoHS compliance to 2011/65/EU.

Medical Device Designers Can Realize Cost-Effective Performance and Patient Safety

Power products that meet IEC 60601, Part 1 are designed to protect patients from risk of accidental shock. When specifying DC/DC converters, be sure to look for products that meet this specification while exhibiting low leakage current. Polytron Devices’ MTWA2 and MTWA4 Series DC/DC converters offer low wattage, low cost and excellent patient protection characteristics to give designers of portable medical devices exceptional performance, efficiency and peace of mind.

For more information about Polytron Devices MTWA2 and MTWA4 Series DC/DC converters, visit


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Deliver More Power to Shrinking Medical Devices Without Sacrificing Space

When it comes to choosing a power supply for medical devices, two things come to mind. First, protect the patient from the risk of electrocution. The second is how to sufficiently power your device within a compact design. 

That’s because medical devices are adding more high-performance, power-hungry functions while also becoming more portable, moving out of hospital environments to clinics, ambulatory care facilities and even patient bedsides. One way to maximize power delivery to shrinking medical devices is to look for a high-power density power supply. Another option? Remove the power source from the unit altogether by choosing an external power supply.

High-power Density External Supplies Address Various Design Challenges

Polytron Devices’ MUI310 Series desktop AC/DC power converters provide ample power for various hospital-based instruments yet are small enough for use with at-home patient monitoring equipment. They come in a small 7.78 × 4.01 × 2.01-inch package with output voltages of 12, 19, 24, 32 and 44V DC and can deliver up to 310 watts of power. By incorporating an external, high-density power supply such as the MUI310 for their medical device, designers can:

  • Reduce device size and weight. Compact size and light weight are crucial to medical device portability, particularly if it will be placed near the bedside on a cart or inside a home.
  • Increase functionality. By freeing up design space, engineers can bolster the device’s capabilities and enhance its performance.
  • Minimize cooling requirements. When you remove the internal power supply to free up precious space, you’re also removing a major source of heat from the system.

MUI310 Series power supplies meet UL/CUL 60601-1, EN60601-1 and IEC60601-1 3rd Edition and 2 X MOPP standards, which can help ease the device manufacturer’s safety and EMC approval process. In fact, 2 X MOPP is the highest level of patient protection from electrocution. The MUI310 Series also offers:

  • An LED power indicator.
  • 4,000V AC input/output isolation.
  • Class I protection, 1,800V AC isolation.
  • 87.5 percent efficiency.
  • Active power correction.

Efficient Use of Space Yields Smarter Medical Device Designs

High-density power supplies can make efficient use of design space, and they can be especially beneficial for medical devices that are packing more functions into smaller units. In many cases, the MUI310 desktop AC/DC converter can eliminate the need for a much larger, heat-generating internal power supply, thereby making it easier to bring your medical device wherever it’s needed.

For more information about Polytron Devices’ MUI310 Series AC/DC power converters, visit


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