Long-lasting and high-efficient AC/DC switching power supplies
For a reliable DC power supply in industrial applications, we offer a wide range of high-quality AC/DC switching power supplies in different designs and performance classes. Designed for 24/7 continuous operation our durable power supply series impress with precisely regulated output voltages, high efficiency, comprehensive safety functions and a rugged circuit design for use in the industrial temperature range. Our highly reliable industrial power supply series are used worldwide in the fields of IIoT/Industry 4.0, embedded IPC, automation, measurement and control technology, process and security technology, POS/POI/kiosk, energy, vision, communication and edge computing.
When developing machines, controls and embedded IPC systems for industrial applications and extreme environmental conditions, particular attention should be paid to the power supply, because the reliability of the entire machine or system depends on the reliability and quality of this module. Regardless of whether it s an open frame, enclosure-housed, DIN rail or encapsulated power supply - nothing works without electricity! Professional power supplies are faced with a very demanding requirement profile. While devices for home or office use are switched on for about eight hours or less on average, industrial power supplies run 24/7, often in closed housings and in the hot system environment with high temperatures. When used in vehicles, on ships or on production machines, they also have to withstand vibrations and shocks. Moisture and a high dust content in the air must not impair their performance. This leads to numerous properties for industrial-grade AC/DC switching power supplies:
On the one hand, an industrial power supply must do its job when the temperature is below zero - for example, when supplying an electronic display board on a platform in deep winter. However, it is more important to specify the upper end of the permissible temperature scale. Not only because it can get warmer in a rolling mill than in a comfortable office, for example, but because the constant exposure to heat shortens the life of the components. In general, the RGT rule (reaction speed-temperature rule, also van ’t Hoff’s rule) applies in this context, which simply states that if the temperature rises by 10 °C, the lifespan of electronic components is roughly halved. In many industrial applications, the ambient temperature can reach +50 °C and more. As a result, the temperature inside the application quickly rises up to +60 °C. Therefore, all system components used, in particular the power supply unit and all components contained therein, should be designed for an extended operating temperature range up to +70 °C or higher.
Industrial switched-mode power supplies with optimized converter topology achieve high efficiencies of up to 94% over the entire power range and thus reduce the heat development of the power supply to a minimum. Precisely dimensioned heat sink solutions, base plate contact cooling and gap filler pad solutions enable fanless operation, which is particularly important in industry with completely closed, mostly dust and waterproof housings. With contact cooling, the heat generated is dissipated via connected housing chassis or a base plate.
With aluminum electrolytic capacitors (electrolytic capacitors), which are used for smoothing and filtering in switching power supplies, the liquid electrolyte evaporates over the operating time by diffusion and thus determines the function and life of the electrolytic capacitors and ultimately the entire power supply. In addition to electrical stress factors, such as ripple current, the aging process is very dependent on temperature of the electrolytic capacitors. As a result of the decreasing amount of electrolyte, the electrical properties of the capacitors change: the capacitance (C) decreases and the loss factor (tan d) increases. In the worst case, a short circuit occurs within the capacitor - with often fatal consequences for the overall system. As already mentioned, the electrolytic capacitors used in switched-mode power supplies are exposed to high levels of permanent thermal stress of at least +60 °C in an industrial environment. For this reason, Bicker Elektronik equips its industrial power supplies with high-quality brand capacitors of the quality class +105 °C / 2000h. Compared to the cheaper +85 °C / 2000h electrolytic capacitors, they guarantee a significantly longer service life (RGT rule) and very high performance.
For applications in which shock and vibration loads are to be expected, all components with a correspondingly high dead weight are fixed in place in high-quality industrial power supplies using a special potting compound. However, the designer does not bother with ‘ordinary’ power supplies - if only for reasons of cost. Mechanically, the FR4 board material used in high-quality industrial power supplies has a significantly higher dimensional stability and service life than inexpensive hard paper boards. The through-hole plating of the printed circuit board ensures long-lasting and stable soldered connections, even under the effects of shock and vibration.
A protective coating (conformal coating) can be applied to defined circuit board and component areas of industrial power supplies to protect against dust and moisture and for safe use in potentially explosive areas. In contrast to spray painting, dip coating can also be used to completely seal areas that are difficult to access with paint. The applied protective varnish ensures the correct functioning of the power supply even under harsh environmental conditions and, depending on the version, even enables the power supply to be operated in potentially explosive areas (ATEX conformity). The elastoplastic protective varnish based on silicone resin forms an abrasion-resistant layer. This protects the power supply unit from damage caused by humidity, electrically conductive contamination and withstands aggressive environmental influences, both chemically and mechanically. The conformal coating effectively prevents corrosion in the form of electrochemical migration and protects against short-circuit bridges between metallizations and solder joints. After the protective varnish covers the primary and secondary circuit of the switching power supply, very good dielectric properties of the paint used (high dielectric strength) are essential. Despite their robustness, high-quality protective coatings remain ‘repairable’, i.e. the varnish can be detached from the substrate with tools in order to exchange damaged or faulty circuit components.
Last but not least, industrial power supplies have extensive certifications in accordance with international safety and EMC standards. This includes the new safety standard based on IEC 62368-1, which will replace the existing standards 60950-1 and 60065 worldwide from December 20, 2020. The demanding EMC standards EN61000-6-2 (interference immunity) and EN61000-6-4 (interference emission) ensure the electromagnetic compatibility of the AC / DC switching power supplies for the industrial sector.