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A switched-mode power supply, SMPS, or simply called a switcher is an electrical power supply that utilizes alternating regulator in order to be highly efficient in the conversion of AC to DC power. Like other makes of power supplies, a switcher power supply transfers power from an AC source like the public utilities to a electrical circuit (e.g., a computer) while converting voltage and current characteristics. A switcher-mode power supply is commonly used to efficiently offer a fixed DC output voltage, usually at a voltage other than the input voltage. Opposite from a linear power supply, the pass transistor of a switching mode power supply switches at very quick (usually between 50 kHz and 1 MHz) between full-on and full-off states, which eliminates lost energy. Voltage regulation is gained by alternating the ratio of on to off time. In contrast, a linear power supply is forced to absorb the unused voltage to regulate the output. This increased efficiency is the leading advantage of a switch-mode power supply. Switching regulators are implemented as replacements for the linear regulators when higher efficiency, smaller footprint or lighter weight are specified. They are, however, more difficult, their switching currents can create electrical noise failures if not carefully managed, and un-complicated designs may have a reduced power factor. A linear regulator generates the desired output voltage by dissipating excess power in ohmic losses (e.g., within a resistor or in the collector–emitter region of a pass transistor in its active mode). A linear regulator delivers either output voltage or current by dissipating the excess electric power as heat, and hence its absolute power efficiency is voltage-out/voltage-in since the volt difference is wasted. In contrast, a switched-mode power supply maintains regulation either output voltage or current by switching ideal storage elements, like inductors and capacitors, into and out of different electronic devices. The best switching elements (e.g., transistors operated outside of their active mode) have zero resistance when "closed" and transfer no current while "open", and so the conversion can theoretically operate with 100% efficiency. The clearly recognized advantages of switching power supplies is far greater efficiency cause the switching transistor wastes very little power while it is not operating within its active region (i.e., when the transistor acts like a switch and either has a very small voltage drop across it or a small current through it). Other improvements include minimized size and lighter weight (from the removal of low frequency transformers which have a high weight) and lower heat generated due to higher efficiency. Issues include greater complexity, the resulting high-amplitude, high-frequency energy that the low-pass filter must minimize to avoid electromagnetic interference (EMI), and a ripple voltage at the switching frequency and the harmonic frequencies thereof. optimized cost switch mode power supplies might tie electronic switching transients to the AC Power line, causing issues with A/V equipment connected to the same mains. Non-power-factor-corrected switching power supplies can cause harmonic distortion.
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Advanced Power Solutions offers a wide range of power supplies from 3-800 Watts. Our industrial power supplies can be modified to meet OEM requirements.
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