A Linear Power Supply is an electrical power supply that provides a stable DC voltage output, free from disruptions or disturbances. This type of power supply is a low-cost and efficient way to provide constant and regulated DC power to operate electronic equipment. Linear power supplies typically operate with a transformer, rectifier circuit, regulator circuit and filter. The transformer steps up the input voltage to a level suitable for the electronic components, the rectifier circuit converts the AC voltage to DC and the regulator is used to regulate and filter the output voltage. Linear power supplies are often used where noise and other forms of electrical interference would disrupt sensitive electronics, such as in medical equipment, telecom systems and light dimming systems.