We already know that the regulator's job is to control the voltage changes, we know that in life are basically using the AC voltage stabilizer, here we give you highlights of the DC voltage regulator. 

 DC voltage regulator according to the adjustment tube state will be divided into a switch-mode power supply and linear power supply. 

 Switch mode power supply is the name suggests is a state between "on" and "off", we call the PWM, simply means that control the arrangement of the capacitors, and inductors. Sample voltage feedback control the output "On" and "off". According to the arrangement of these components and switches, we can use a voltage regulator to generate multiple output voltage, output voltage is very flexible. In most cases, the same voltage output, we will generally use a switching regulator. 

 Linear regulator, also known as the parameter regulator, LDO is a classic parameter regulator, a transistor or FET, the voltage through this area and then adjust the voltage of a good input in its linear region, with of output control voltage stability. This is the so-called dropout voltage, the difference it will be the output voltage and input voltage controlled at about 100mV. Some LDO regulator allows it to have a high saturation on the expansion of the difference, basically about 200mV. 

 Regulator (http://www.pandeng.org.cn)