We usually use dry batteries, lead-acid batteries, nickel-cadmium, nickel-metal hydride, lithium-ion batteries belong to the chemical power supply, each with its own advantages and disadvantages. With the development of science and technology, and produced intelligent batteries; in terms of rechargeable battery materials, U.S. researchers found that a manganese iodide, with which you can create a cheap, compact, long discharge time, many times after charging still maintain good performance of environmentally friendly rechargeable batteries.

Switching DC regulated power supply is the use of modern power electronics technology, control the switching transistor turn on and off time ratio, to maintain a stable output voltage of a power supply. Its circuit form mainly has single-ended flyback, single-ended forward, half-bridge, push-pull and full-bridge. The basic switching DC regulated power supply mainly includes input grid filter, input rectifier filter, inverter, output rectifier filter, control circuit, and protection circuit.

The advantages of switching DC regulated power supply are small size, light weight, stability and reliability. Disadvantages relative to the linear DC regulated power supply ripple is large (generally Less than or equal to 1%V P-P). The following classification introduces several types of switching DC regulated power supplies:

AC/DC power supply This type of power supply is also known as primary power supply, which obtains energy from the power grid, and gets a DC high voltage after high-voltage rectification and filtering for DC/DC converter to obtain one or several stable DC voltages at the output, and the power is from a few watts to a few kilowatts, which is used in different occasions.

Communication power supply Communication power supply is in essence a DC/DC converter type power supply, but it is generally DC-48V or -24V power supply, and use the backup battery as DC supply backup, the DC supply voltage is converted into the circuit working voltage. Generally, it is divided into three types: central power supply, layered power supply and single board power supply, and single board power supply is the most reliable.

Radio power supply Input AC220V/110V, output DC13.8V, power is determined by the power supplied to the radio. In order to prevent the AC network power failure to affect the radio work, and need a battery pack as a backup, so this type of power supply in addition to the output of a 13.8V DC voltage, but also has a battery charging automatic conversion function.

Special power supply Current power supply, 400Hz input AC/DC power supply, etc., can be categorized into this kind of power supply, which can be selected according to special needs.