We are AEconversion, your specialists for customised power supply solutions. Our company specialises in the development and manufacture of customised systems that are precisely tailored to your specific requirements. We also develop the right cooling concept for your power supply to ensure optimum performance and longevity. With our many years of experience and our commitment to the highest quality, we offer you innovative and reliable solutions that meet your highest demands. Discover how our well thought-out approaches to cooling and our customised power supplies can advance your projects.
The cooling of power supplies is a key factor that significantly influences not only the efficiency, but also the service life and reliability of these devices. As power supplies become more compact and feature-rich, thermal management is an increasing challenge. Effective thermal design and appropriate heat dissipation are crucial to ensure high reliability and minimise the risk of overheating and failure.
With advancing miniaturisation and increasing demands on power supplies, the requirements for the thermal concept are inevitably also increasing. Manufacturers therefore invest a lot of time and resources in optimising heat dissipation in order to maximise operational reliability and avoid failures. This requires an in-depth understanding of the various cooling methods, their specific advantages and disadvantages and their application in different scenarios.
Convection cooling utilises the natural circulation of air to dissipate heat. This method is relatively simple and low-maintenance, but its efficiency is limited. It is particularly suitable for applications with low to medium power density, where heat development is moderate and no extreme temperature increases are to be expected. Natural convection is based on the fact that warm air rises and cool air flows in, creating a constant flow of air that draws the waste heat away from the appliance. Fans are often used when heat build-up is high. The power supply with AC and DC input and multiple outputs on the reference page is an example of one of our developments with convection cooling.
Fans are often used because they are easy to integrate and maintain. They offer a high cooling capacity and are available in various sizes and performance levels. The dimensioning and positioning of the fans is crucial for their effectiveness. A well-placed fan can significantly improve heat dissipation by channelling air directly over the hottest components, preventing hotspots. Fans are also relatively inexpensive and easy to replace, making them a practical choice for many applications. On our reference page, for example, the Ultra-efficient battery charger 2kW is an example project with a fan.
In addition to noise, which can be disturbing in quiet environments, fans can also draw dust and moisture into the device. This leads to contamination and possible failures of the power supply unit. In addition, the system resistance must be overcome, which makes it difficult to select the right fan. A fan must not only be able to move sufficient air, it must also be able to overcome the resistance created by the housing architecture. This requires precise calculation and selection to ensure that the fan delivers the required performance.
Contact cooling dissipates the waste heat directly via a thermally optimised base plate. This method avoids the typical problems of fans and offers a noiseless cooling option. It is particularly efficient when it comes to dissipating heat from the critical components of the power supply.
With contact cooling, the power supply is thermally coupled to a metal housing wall or a heat sink. This efficiently dissipates the heat without the need for an active fan. This method is particularly suitable for applications where noise and contamination could be a problem. The base plate, often made of aluminium or copper, ensures even heat distribution and enables effective heat dissipation. In some cases, contact cooling can also be combined with fan cooling to further increase efficiency. Here, the base plate provides the primary heat dissipation, while the fan generates additional air circulation and distributes the waste heat more quickly, which can be particularly beneficial in high-performance applications.
Contact-cooled power supplies are ideal for applications in noise-sensitive environments, such as medical equipment or home automation, where silence is critical. They offer a long service life as there are no moving parts to wear out. They also reduce maintenance effort and costs as there are no fans to clean or replace. The Power supply 130 W for building technology on the reference page is an example of one of our developments with contact cooling.
Contact cooling has some disadvantages. An uneven contact surface between the objects to be cooled and the heat sinks can significantly reduce the efficiency of heat transfer. In addition, contact cooling may require regular maintenance if contamination or oxidation occurs and can impair performance. The mechanical pressure required for effective heat transfer can lead to damage to the components, posing a further challenge.
Another disadvantage is the limited cooling capacity at very high heat loads, which may require additional cooling methods. Finally, thermal contact resistance at the interfaces between different materials can affect the efficiency of heat transfer, which requires additional design and material considerations.
Liquid cooling utilises a liquid cooling medium for heat dissipation and is particularly effective for applications with high power density. It offers higher thermal conductivity and enables a more compact heat sink design, which is particularly advantageous in confined environments.
The use of a liquid cooling medium allows heat to be dissipated efficiently. The thermal resistance between the heat sink and cooling medium is lower than with air cooling, which leads to improved heat conduction. The coolant is pumped through the system in a closed circuit. It flows through channels and heat sinks, absorbing the heat from the hot components and transporting it to an external heat exchanger. In the heat exchanger, the heat is transferred to the ambient air or another medium. The cooled liquid flow then returns to the circuit to absorb heat again. This process requires a pump to drive the coolant circuit and hoses or pipes to transport the coolant between the various components.
Liquid cooling is often used in electromobility and high-performance applications, such as in data centres or industrial machines, where large amounts of heat need to be dissipated quickly and efficiently. It enables a higher power density and reduces the size of the required heat sinks. In addition, liquid cooling can help reduce energy costs and the CO2 footprint, as it works more efficiently and requires less energy than conventional air cooling systems. We have developed a system with liquid cooling for a power supply with an output of 12kW, which are used in large numbers in parallel in data centres in racks.
Although liquid cooling offers many advantages, there are also some disadvantages that need to be taken into account. One of the main disadvantages is the higher complexity of the system. Liquid cooling requires careful planning and installation as it consists of several components such as pumps, hoses, heat exchangers and heat sinks. These components must be precisely coordinated to ensure efficient cooling. In addition, liquid cooling requires regular maintenance to ensure the pump is functioning properly and to top up or change the coolant.
Another disadvantage is the potential risk of leaks. As the cooling medium is liquid, leaks in the hoses or connections can lead to liquid escaping, which not only impairs the cooling performance but can also cause damage to the electronic components. In addition, the cost of installing and maintaining a liquid cooling system is higher than with air cooling solutions, which can be a decisive factor, especially for smaller budgets.
The operating temperature of a power supply has a direct influence on its performance and service life. At higher temperatures, there may be a reduction in performance (temperature derating) to prevent overheating. It is therefore crucial that the maximum permissible operating temperature is not exceeded in order to ensure the reliability and efficiency of the power supply.
The determination of the required volume flow for cooling is based on the power loss of the power supply and the maximum permissible temperature difference. A suitably dimensioned fan must deliver the required airflow to efficiently dissipate the waste heat. The formula for calculating the volume flow takes several factors into account, including the power dissipation, the temperature difference and specific correction factors, which can vary depending on the application. The general formula is:
Here:
ṁ stands for the mass flow.
V for the volume flow.
g for the density of air.
c for the specific heat air.
𝑃 for the power loss of the power supply in watts (W).
Δ𝑇 for the temperature difference.
Suppose we have an application with a power loss of 115 watts and a maximum supply air temperature of 33°C. The maximum permissible temperature in the housing is 48°C, which results in a temperature difference (Δ𝑇) of 15 K. The density of air is 1.225 kg/m³. The specific heat of air (c) is 1.005 kJ/kg ⋅ K.
The volume flow rate is calculated as follows:
This volume flow of 0.373 m³/min is required to dissipate the waste heat efficiently. In practice, it is important to check the actual volume flow, as this depends on other factors such as the system resistance, the packing density of the components and the flow velocity of the airflow. A fan must therefore not only move sufficient air, but also be able to overcome the resistance created by the housing architecture.
The service life of electronic components, especially electrolytic capacitors, is highly temperature-dependent. Increasing the operating temperature by 10°C can halve the service life of the components. It is therefore important to keep operating temperatures as low as possible. Careful planning and correct temperature management can significantly extend the service life of power supply units.
To control the operating temperatures, various measures can be taken. These include the use of high-quality heat sinks, optimising air circulation in the housing and the use of temperature monitoring systems. These measures help to keep the temperature within a safe range and maximise the efficiency of the power supply.
Some power supply units can be operated with pure convection cooling as well as with active cooling. With pure convection cooling, the performance is often reduced as the natural air circulation can dissipate less heat than an active cooling mechanism. In contrast, active cooling allows the full rated power of the power supply to be utilised, as forced air circulation or other cooling methods dissipate heat more efficiently. This flexibility allows it to be used in different applications and environments, depending on the specific cooling and performance requirements of the power supply unit.
The mounting position can influence the cooling performance. For optimum cooling, the installation position should be in accordance with the manufacturer’s recommendations. If the mounting position differs, the temperature of critical components must be monitored to ensure that no overheating occurs. An incorrect mounting position can lead to heat build-up and significantly impair the efficiency of the cooling.
We provide you with precise recommendations on the dimensioning and positioning of fans to ensure sufficient cooling and the extraction of maximum power. Careful consideration of the flow direction and volume flow can optimise cooling performance and extend the service life of the power supply.
Thermal interface materials (TIMs) fill microscopically small cavities between two surfaces and improve thermal conductivity. They are crucial for efficient heat transfer in a cooling system. Without suitable thermal interface materials, heat transfer would be inefficient, which could lead to overheating and potential failures.
There are different types of thermal conductive materials, each with specific properties and areas of application:
Each thermal conductive material has specific advantages and disadvantages. Thermal conductive films are easy to use and offer consistent results, while pastes are more flexible but more difficult to handle. Adhesives provide adhesion but are often sticky and difficult to work with. Phase change materials are efficient but more expensive.
At AEconversion, we work closely with you to find the optimum heat conducting material for your specific applications. Choosing the right material depends heavily on the individual requirements and operating conditions. For applications that require high thermal conductivity and flexibility, thermal pastes may be the best choice. If, on the other hand, a clean and repeatable application is the priority, thermally conductive films are ideal. With our expertise and your specific application knowledge, together we will find the best solution to significantly improve the efficiency and reliability of your cooling.
At AEconversion, we offer comprehensive support in the selection of suitable power supplies and cooling solutions. Our experienced team will advise you on the best components and help you find high-performance and durable solutions. This personalised advice is particularly important, as the right choice of power supply and cooling solution is crucial for the efficiency and reliability of your entire system. The best contribution to the thermal concept is to increase the efficiency of the device and thus reduce power loss. We achieve this through optimised architectures including project-specific magnetic components.
At AEconversion, we offer a broad portfolio of high-quality AC/DC and DC/DC power supplies as well as other products. Our development team works closely with you to find the best possible solutions for your specific applications. Thanks to our intensive collaboration with leading component manufacturers and our in-depth expertise, we develop customised solutions that are precisely tailored to your requirements.
Interested in our customised power supply solutions? Contact us today and let’s work together to develop the ideal solution for your requirements . At our company, we pride ourselves on delivering innovative and reliable power supply systems that meet the highest standards and help you achieve your goals.
By loading the map, you accept Google's privacy policy.
Mehr erfahren
© Copyright 2019 by AEconversion GmbH & Co. KG. All Rights Reserved.
