Battery eliminators, also known as AC-DC power supplies or wall warts, are devices that convert alternating current (AC) power from a wall outlet into direct current (DC) power that can be used to power electronic devices.
Battery eliminators typically consist of a transformer, rectifier, and regulator circuitry housed in a compact plastic or metal case with a cord and plug that can be inserted into a wall outlet. They are available in a range of voltage and current capacities to match the requirements of the electronic device being powered.
Battery eliminators are commonly used in situations where a device needs a steady and reliable power source, and where using batteries would be inconvenient, expensive, or environmentally unfriendly. They are used in a wide range of applications, including powering electronic devices such as radios, alarm clocks, and portable DVD players, as well as powering hobby projects and laboratory equipment.