Editing DC-to-DC converter (section)

== Uses ==
{{See also|High-voltage direct current}}
DC-to-DC converters are used in portable electronic devices such as [[cellular phone]]s and [[laptop computer]]s, which are supplied with power from [[Battery (electricity)|batteries]] primarily. Such electronic devices often contain several sub-[[Electrical network|circuits]], each with its own voltage level requirement different from that supplied by the battery or an external supply (sometimes higher or lower than the supply voltage).  Additionally, the battery voltage declines as its stored energy is drained.  Switched DC to DC converters offer a method to increase voltage from a partially lowered battery voltage thereby saving space instead of using multiple batteries to accomplish the same thing.

Most DC-to-DC converter circuits also regulate the output voltage. Some exceptions include high-efficiency [[LED power sources]], which are a kind of DC to DC converter that regulates the current through the LEDs, and simple [[charge pump]]s which double or triple the output voltage.

DC-to-DC converters which are designed to maximize the energy harvest for [[photovoltaic systems]] and for [[wind turbine]]s are called [[power optimizer]]s.

Transformers used for voltage conversion at mains frequencies of 50–60&nbsp;Hz must be large and heavy for powers exceeding a few watts. This makes them expensive, and they are subject to energy losses in their windings and due to eddy currents in their cores. DC-to-DC techniques that use transformers or inductors work at much higher frequencies, requiring only much smaller, lighter, and cheaper wound components. Consequently these techniques are used even where a mains transformer could be used; for example, for domestic electronic appliances it is preferable to rectify mains voltage to DC, use switch-mode techniques to convert it to high-frequency AC at the desired voltage, then, usually, rectify to DC. The entire complex circuit is cheaper and more efficient than a simple mains transformer circuit of the same output. DC-to-DC converters are widely used for DC microgrid applications, in the context of different voltage levels.