Basic Concepts of Switching Power Supplies
With the development of power electronics technology, power electronic equipment and people's work, life is increasingly close, and electronic equipment are inseparable from a reliable power supply, into the 80's computer power supply to achieve the full realization of the switching power supply, the first to complete the computer's power supply replacement, into the 90's switching power supply has entered a variety of electronic and electrical equipment in the field of programmable control exchanges, communications, electronic testing equipment, power supply, control equipment, etc. have been widely used switching power supply, more to promote the rapid development of switching power supply technology. In the 1990s, switching power supply has entered the field of various electronic and electrical equipment, such as programme control switches, communication, electronic testing equipment power supply, control equipment power supply, etc. Switching power supply has been widely used, which has promoted the rapid development of switching power supply technology. Switching 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, switching power supply is generally by the pulse width modulation (PWM) control IC and MOSFET composition. Switching power supply and linear power supply compared to the cost of both with the increase in output power and growth, but the rate of growth of the two are different. Linear power supply cost at a certain output power point, but higher than the switching power supply, this cost reversal point. With the development of power electronics technology and innovation, so that the switching power supply technology in continuous innovation, this cost reversal point increasingly to the low output power end of the move, which provides a wide range of switching power supply development space. Switching power supply high-frequency is the direction of its development, high-frequency switching power supply miniaturisation, and switching power supply into a wider range of applications, especially in the field of high and new technology, promoting the miniaturisation of high-tech products, lightweight. In addition, the development and application of switching power supply in energy saving, resource saving and environmental protection are of great significance.
Switching power supply is to control the switching tube through the circuit to carry out high-speed road pass and cut-off. The direct current into high-frequency alternating current provided to the transformer for transformer, thus generating the required one or more groups of voltage! Huawei high-frequency alternating current is the reason that high-frequency alternating current in the transformer transformer circuit is much higher than the efficiency of 50HZ. So the switching transformer can be made very small, and work is not very hot! The cost is very low. If not 50HZ into high frequency that switching power supply is meaningless! Switching transformer is not mysterious. Is an ordinary transformer! This is a switching power supply. Switching power supply can be roughly divided into isolated and non-isolated two kinds of isolated must have a switching transformer, and non-isolated may not necessarily have.
In the same power, the higher the switching frequency, the smaller the size of the switching transformer, but the higher the requirements of the switching tube; switching transformer can have more than one secondary winding or a winding with more than one tap, in order to get the desired output; generally should also add some protection circuitry, such as no-load, short-circuit and other protections, otherwise it may be burned switching power supply.
