Abstract
With the rapid development of power electronics, power electronics equipment and people work and live closer ties between the electronic equipment can not do without a reliable power supply, computer power in 80 years of the switching power supply with the first to complete the computer's power updating, switching power supply into the 90's have access to a variety of electronic, electrical devices, program-controlled switches, communications, electronic test equipment power supply, power supply and other control devices are widely used in switching power supply, switching power supply also contributed to the rapid development of technology .
Switching power is the use of modern electronic technology, control switch transistor turn-on and turn-off time ratio of a stable output voltage of one kind of power supply, switching power supply generally pulse width modulation (PWM) control IC and MOSFET form. Switching and linear power supply compared to the cost of both the output power increased with the increase of growth, but growth rate varied between the two.
Linear power supply costs in a given output, rather than switching power supply, the cost of reversal.With the development of power electronics technology and innovation, making switching power supply technology in constant innovation, increasing the cost of reversal point move to the low output power side, which for the switching power supply provides a broad development space, a general show meaningful.
Keywords：Switching power supply, pulse width modulation，linear power supply，MOSFET
