A voltage regulator is a mechanical or electrical device that ensures that the voltage across a circuit is maintained at a constant fixed value or range of values, even if an input voltage is unstable. Generally, a feedback loop, which tells the device whether to increase, decrease or stop producing voltage, is used to retain the correct voltage. Regulators are used not only to protect devices from changes in voltage, but also to effectively convert a particular input/output range to a different set of values.
Where is an automatic voltage regulator necessary?
Voltage regulators are used in a wide variety of different electric devices, from cars and generators to solar power devices and power line architecture. They are also essential in IT and high-tech businesses, because they are part of computer hardware. Each device or setting may require a different type of voltage regulator, so consult your manufacturer's specifications before purchasing a regulator.
Most importantly, you want to ensure that the input voltage is within the allowed range for your particular type of regulator; otherwise, damage to your device may result. Consulting the particular part number of the voltage regulator can be helpful. For example, the 7805 voltage regulator is designed to put out 5 volts and accept an input of about 7.5 to 35 volts. The 7812 voltage regulator is similar, but accepts an input of 12 volts.
What types of voltage regulators are there?
A linear regulator, as the name implies, operates in a linear region and consists of several transistors. Most commonly, linear regulators are used in computers and integrated circuits, because of their high quality and low noise output.
Another type of regulator, a step-up regulator, differs from the linear regulator in that it can invert or "step up" the voltage from the power supply. This results in a usable voltage that is higher than the actual voltage in the power supply itself, and can be particularly useful when repurposing electrical equipment. It is important to keep in mind the fact that linear and step up regulators cannot be substituted for one another without causing damage to a device or producing unintended effects.