AC voltage power grid transformation into a stable 12V DC output isthe converter inverter and the inverter is the adapter output 12V DC voltage into high-frequency high-voltage alternating current; two parts also have adopted the currently used pulse width modulation (PWM) technique. Its core part is a PWM integrated controller, the Adapter uses the UC3842, the inverter uses the chip. Working voltage range of 3.6 ~ 40V, its internal with an error amplifier, a regulator, oscillator, a dead time control of PWM generator, low voltage protection circuit and short circuit protection circuit, etc..