What is a switch power supply?
What is a switching power supply?
With the development and innovation of power electronics technology, switching power supply technology is also constantly innovating. At present, switching power supply is widely used in almost all electronic equipment due to its small size, light weight and high efficiency. It is an indispensable power supply method for the rapid development of today's electronic information industry.
Switching power supply is a kind of power supply that uses modern power electronic technology to control the time ratio of switching on and off to maintain a stable output voltage. Switching power supply is generally composed of pulse width modulation (PWM) control IC and MOSFET.
The switching power supply is relative to the linear power supply. Its input terminal directly rectifies the alternating current into direct current, and then under the action of the high-frequency oscillating circuit, uses the switching tube to control the on-off of the current to form a high-frequency pulse current. With the help of an inductor (high frequency transformer), a stable low voltage direct current is output.
Since the size of the magnetic core of the transformer is inversely proportional to the square of the operating frequency of the switching power supply, the higher the frequency, the smaller the core. In this way, the transformer can be greatly reduced, reducing the weight and volume of the power supply. And because it directly controls DC, this power supply is much more efficient than a linear power supply. This saves energy, so it is favored by people. But it also has disadvantages, that is, the circuit is complicated, maintenance is difficult, and the pollution to the circuit is serious. Power supplies are noisy and may not be suitable for use in some low-noise circuits.
The characteristics of switching power supply
A switching power supply is generally composed of a pulse width modulation (PWM) control IC and a MOSFET. With the development and innovation of power electronics technology, switching power supplies are widely used in almost all electronic devices because of their small size, light weight and high efficiency, which shows its importance.
Classification of switching power supply
According to the way switching devices are connected in the circuit, switching power supplies can be generally divided into three categories: series switching power supply, parallel switching power supply, and transformer switching power supply.
Among them, the transformer-type switching power supply can be further divided into: push-pull type, half-bridge type, full-bridge type, etc. According to the excitation of the transformer and the phase of the output voltage, it can be divided into: forward type, flyback type, single excitation type and double excitation type.
