Today, switching power supplies are used in almost all electronic devices: they are state-of-the-art in computers and televisions as well as in industrial equipment and systems.
Compared to analog-controlled power supplies, switched-mode power supplies score points for their high efficiency, low heating and high reliability. In addition, the high clock frequency enables small component sizes and low weights, which has a positive effect on costs.
Properties of industrial power supplies
Industrial power supplies are predestined for harsh environments because they can withstand high temperatures and have a very small size.
However, there are some other important parameters to consider when assessing the quality and reliability of switching power supplies. These include efficiency, thermal management, permissible operating temperature, derating curves for input voltage and ambient temperature, and bridging time in the event of a power failure.
A sophisticated heat management system allows the power supply to be installed in any direction. In an industrial environment, an open power supply should provide constant performance up to an ambient temperature of at least 70 °C. The power supply should be installed in an open circuit.
The decisive factor, however, is the temperature derating curve, which indicates the maximum permissible output power depending on the ambient conditions. Power supplies of inferior quality, for example, also lack the necessary protective mechanisms to automatically throttle the power output in the worst-case scenario.
Three types of industrial power supplies at a glance
In principle, the market differentiates between three types of industrial power supplies – depending on application requirements and design.
DIN rail power supplies
DIN rail power supplies are used for simple installation in technical switch cabinets. The size of the power supply unit is adapted to the performance requirements. For this purpose, the size of the device or housing is defined in subunits (TE): One TE corresponds to 18 mm; more powerful models have up to 4 TE.
Switch mode power supplies with closed design
Switching power supplies with closed design (in case) are available for direct mounting. They usually have a very good performance. The reason for this is the larger space in the housing, which can be used to compensate for the high waste heat. In addition, many models of this type have integrated fans.
The connections are often designed for large cable cross-sections, so that the closed switching power supplies in the case are ideally suited for demanding applications thanks to optimum supply and discharge. Compactness and cost efficiency are just as important for these switched-mode power supplies as they are for DIN rail power supplies.
Open Frame switching power supplies
However, power supplies without housings, so-called open frame switching power supplies, are particularly cost-effective. Here, all components are placed on a compact circuit board which, due to its small size, can be easily installed in devices with existing housings.
Open Frame power supplies are ideally suited for miniaturization and flexible installation – making them ideal for integrated (embedded) applications in small devices.
The most important quality features and parameters at a glance
– Rated power: The power that can be delivered in continuous operation.
– High efficiency: It determines the heat loss to be dissipated. High efficiency reduces operating costs in the long term. In industrial environments, power supplies are usually in continuous operation – unlike in building technology, for example. The power supplies developed for this purpose are therefore optimized for a particularly high degree of efficiency of up to 93 percent.
– Low costs: Low acquisition costs, low operating costs with high efficiency and a long service life. High efficiency results in low power dissipation, which results in less heat generation. This in turn reduces the load on the components, which increases service life and reliability – resulting in lower overall costs.
– Small size (volume) leads to higher power density.
– Input voltage derating: Indicates which power can actually be taken at which input voltage.
– Good temperature behaviour: The application at particularly high or low temperatures should be possible (approx. -20 °C to +80 °C).
– Low weight: especially important for mobile applications
– Mounting position: It indicates which alignments of the power supply unit are permissible in order to reliably dissipate the heat loss.
– Low power dissipation: An active PFC (power factor correction) reduces harmonics and energy losses.
– Safety: Protection against short-circuit, overload, overvoltage and overheating.
– Electromagnetic compatibility: According to EU standards, electrical devices must not interfere with each other.
The switching power supplies from Mean Well
Using the example of the manufacturer Mean Well, we present you a broad overview of various switching power supplies. Mean Well offers comprehensive solutions for power supply. For industrial use, Mean Well offers a wide range of switching power supplies such as DIN rail, open frame and case models, as well as power supplies for the medical sector.
The manufacturer focuses in particular on products with high added value and extended functions. The switched-mode power supplies have already proven themselves many times over on the market in terms of quality, product variety and a very good price/performance ratio.
Since its foundation in 1982, the manufacturer has been conducting a comprehensive market analysis, recording customer requirements and developing a cost-effective standard with the highest possible coverage.
DIN rail power supplies
In the field of DIN rail power supplies, the HDR series scores with its high performance in a particularly small design, especially in comparison to the first generation, the DR series.
The power supplies with 15W (HDR-15), 30W (HDR-30) and 60W (HDR-60) are mainly used in building automation and house control, as they all comply with protection class II.
The HDR series from Mean Well has a step-shaped plastic housing, an input voltage range from 85 to 264VAC and offers models with 5V, 12V, 15V, 24V and 48V.
The height of all power supplies is only 90 mm, the width between 17.5 mm and 70 mm. The models can be mounted on the standard DIN rails TS-35/7.5 and TS-35/15.
Their features also include low no-load consumption of <0.3W, high efficiency of up to 91% and an adjustable DC output voltage as well as a wide operating temperature range (-30 to +70 °C).
Switching power supplies for DIN rails
New in Mean Well’s portfolio are the extra slim switching power supplies with 150W for DIN rail mounting. They are currently the smallest on the market and have reinforced insulation to protection class II.
They feature input voltages from 85 to 264VAC, a low power consumption at zero load of less than 0.3W and a high efficiency of 90.5 %. They also have an adjustable DC output voltage of ±10% and a wide operating temperature range of -30 to +70 °C.
The series is designed for overvoltage category III (OVCIII) applications, enabling a wide range of applications. These include building automation, household control systems, industrial control systems and electromechanical devices.
HDR-150 complies with the EU standard EN61000-3-2 Class A for harmonic currents, is certified in accordance with current safety regulations and, with a height of 90mm and a width of 105mm (6TE), complies with the EU standard EN43880 for DIN rail installation.
Direct mounting power supplies
The UHP UHP-200/350/500 and UHP 1000 line of closed direct mount power supplies are particularly user-friendly thanks to their slim U-bracket design and flat profile height.
The series feature a high efficiency of up to 95% at a high ambient temperature of -30 to +70 °C with simple air convection.
These power supplies provide a power reserve of 150% (100ms) of rated current for peak loads and can be used up to 5000 meters above sea level.
Digital Power Supplies
For an intelligent power supply, Mean Well offers the digital, highly efficient power supplies of the new 3200 watt series DBU, DBR, DRP and DPU. They are based on a single digital platform, resulting in power supplies and battery chargers for device installation or rack mounting.
The digital devices in the slim 1U profile have a high power density of 37W/in³, an optimized efficiency behavior depending on the load and, as a result, a maximum efficiency of up to 94.5 percent.
The products equipped with an active PFC operate with an input voltage of 90-264VAC and provide the DC voltages most frequently required in industry.
The series offers a high degree of design flexibility, as it can be individually integrated into applications with various integrated, analog or digital controllable functions, such as programming charging curves, parameterization of output characteristics and overload protection, or remote function.
The digital design improves performance performance and reliability. The smaller number of analog components, such as power management ICs, makes devices much more compact and increases power density.
In addition to use in industrial 4.0 applications or industrial automation, the series are also suitable for telecommunications equipment.
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