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Power Supply

Power Supply

A power supply is an electronic assembly that accepts input power in whatever form is available and converts it to the form required for a given application - a common example is the charger for a cell phone. A power supply may convert AC to DC, increase or decrease the voltage and current, and regulate (stabilize) the output so that it is unaffected by variations in the input power source. A power supply also usually provides a means to adjust the output with a built-in control or by using an externally located control connected to it, or with a control voltage or digital input. It may also include some means for monitoring its output, such as an LED indicator or a meter. One power supply may provide multiple outputs.

A power supply is usually constructed as a discrete assembly containing nothing other than its own circuitry, though it may be mounted within the equipment it is powering. It may be enclosed in a metal case; however, a very small power supply (such as a cell phone charger) may be encapsulated within a plastic shell.

A power supply consists of one or more transformers and smaller components such as semiconductors, resistors and capacitors. Because a power supply may dissipate a significant amount of heat, one should not be located in a confined space where that heat cannot be readily radiated to surrounding air.

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