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The demand for more efficient, powerful and lightweight systems drives the continued miniaturization of almost all electronic systems. This is also true for power supplies and they are expected to become more and more compact over time. The high-end industrial and medical market, in particular, is set to grow steadily over the next decade.
The new power supply
It is aimed precisely at these sectors with models approved according to the most recent safety standards for medicine (IEC/UL 60601) and ITE (IEC/UL 62368). Its fanless design focuses on high levels of efficiency and reliability to offer design engineers a high degree of flexibility during system integration, especially in laboratory and home healthcare, robotics and automation applications. The VCCS300 is a true conduction-cooled power supply that provides best-in-class performance when used in a conduction, convection, or forced air-cooled configuration. At only 310g, it is capable of delivering 300W output power from a tiny 2 x 4-inch (50,8 x 106,6mm) package with a power density of more than 23W/inch3 and, depending on the chosen cooling technique, they can deliver up to 80% more power than their competitors' products in the same package.
The increased power output allows system integrators to:
- Increase functionality without increasing the size of your product to accommodate larger power supplies, save on redesign costs, and shorten time to market.
- Reduce the size of products by eliminating larger power supplies with the aesthetic improvement that brings along with savings in transportation costs and carbon emissions.
- Increase system reliability by lowering internal system temperatures.
Advanced knowledge of power supplies
Designing high-density power supplies requires a thorough understanding of the interaction and interrelationship between electrical design, mechanical design, thermal management, electrical safety, and EMI. The critical elements in downsizing a power supply are high efficiency and how design engineers deal with the difficult challenge of internal heat dissipation. Inefficiencies create heat, which if not effectively removed can excessively increase product temperatures and lead to premature failure or reduced long-term reliability. When a 300W power supply only reaches 90% efficiency, it wastes 33W in the form of heat that must be removed. However, when the same 300W power supply is 95% efficient, it only generates 16,5W of wasted heat.
Excess heat can be removed by a combination of natural convection, conduction, or forced-air cooling techniques. Vox Power has concentrated its most recent design efforts on conduction cooled products as it gives the customer the flexibility to choose the best cooling system for their application. When properly installed, proper cooling techniques allow for very effective heat dissipation and the new power supply to operate at full power at ambient temperatures up to 40°C. By combining these units in parallel or in series, output powers of 600W, 900W and higher can be obtained, thus serving as a power platform for numerous products with various output powers. The power supply output is BF rated for medical applications and meets various MIL-STD standards, making it suitable for harsh environments.
New design topologies in power supplies
In the VCCS300 series, our engineers have used several modern design topologies and world-class components in a comprehensive design methodology to achieve efficiencies up to 95%. High efficiency is complemented by rigorous attention to circuit board layout and mechanical construction to ensure that heat-generating components, such as power switches and magnetic components, are mounted in a way that optimally balances the load. heat distribution throughout the product. The use of advanced materials in the plate increases the thermal diffusivity as they improve and accelerate the thermal transfer in the integrated base. This base provides a simple interface that the end user can easily connect to a metal chassis or system heatsink to facilitate conduction cooling, thus delivering up to 300W power output at 40°C without fans.
As a result, high levels of efficiency and good thermal management eliminate the need for a dedicated cooling fan which comes in handy in higher power applications where there is virtually no airflow. For larger systems with a built-in fan, the VCCS300 can deliver full power at 50°C with system airflow starting at 1m/s.
During the product design phase, our engineers applied a unique design philosophy with the goal of simplifying complex circuit solutions, reducing the number of components, and eliminating design issues at their source. This philosophy is evidenced by the excellent EMI response of the unit. Meeting the stringent medical EMC standards in a power supply is always a major challenge and many manufacturers often incorporate a larger filter to overcome this issue. At Vox Power we have spent many hours of research, circuit simulations, testing, and optimization to eliminate sources of EMI noise. As a result, the VCCS300 has a very small EMI filter which makes it even easier to reduce overall size without compromising performance. The product complies with the Class B limitations of the Conducted and Radiated Emissions Standards (EN55011) with a margin of several dB over the entire frequency range. Spending time and resources to identify and eliminate EMI sources throughout the design not only helps to reduce the size of the product but also improves its reliability.
The higher level of isolation and clearance and creepage requirements for medical power supplies also make downsizing more difficult. In the new unit we have paid special attention to the design of the mechanical insulators in order to obtain a BF rated output without affecting the thermal performance or the dimensions of the product.
Two segments of the power market converge in the new power supply. The first is for miniaturized applications that may have limited space for a power supply but need more power to achieve the functions required by the application. The VCCS300 addresses this challenge by offering much higher power output. This allows for more features and is beneficial to customers in your market. Such applications include home health care, mobile equipment, ventilators, respirators, and dental equipment.
The second segment is made up of higher power applications where customers want downsizing but are limited by the large dimensions of power supplies. The VCCS300 delivers up to 300W output power that has previously only been available on much larger 5 x 3-inch power supplies. Among these applications are lasers for medicine and industry, automation, robotics and 3D printing.
