What Are Voltage Regulators and How Do They Work in Electronics? GA S REGULAR Menu Lifewire Tech for Humans Newsletter! Search Close GO Computers, Laptops & Tablets > Accessories & Hardware

What Are Voltage Regulators and How Do They Work in Electronics?

Voltage regulators deliver constant, stable voltage to sensitive electronics

By Matthew Burris Matthew Burris Writer Kettering University DeVry University Former Lifewire writer Matthew Burris is an engineer, writer, inventor, small business founder, and startup enthusiast with knowledge of electrical components. lifewire's editorial guidelines Updated on December 2, 2020 Tweet Share Email Tweet Share Email Accessories & Hardware The Quick Guide to Webcams Keyboards & Mice Monitors Cards HDD & SSD Printers & Scanners Raspberry Pi Voltage regulators take an input voltage and create a regulated output voltage regardless of the input voltage at either a fixed voltage level or an adjustable voltage level. This automatic regulation of the output voltage level is handled by various feedback techniques. Some of these techniques are as simple as a Zener diode. Others include complex feedback topologies that improve performance, reliability, and efficiency and add other features like boosting output voltage above the input voltage to the voltage regulator. Voltage regulators are a common feature in many circuits to ensure that a constant, stable voltage is supplied to sensitive electronics. Mark Gittelman

How Linear Voltage Regulators Work

Maintaining a fixed voltage with an unknown and potentially noisy input requires a feedback signal to clarify what adjustments need to be made. Linear regulators use a power transistor as a variable resistor that behaves like the first half of a voltage divider network. The output of the voltage divider drives the power transistor appropriately to maintain a constant output voltage. Because the transistor behaves like a resistor, it wastes energy by converting it to heat—often lots of heat. Since the total power converted to heat is equal to the voltage drop between the input voltage and the output voltage times the current supplied, the power dissipated can often be very high, demanding good heatsinks. An alternate form of a linear regulator is a shunt regulator, such as a Zener diode. Rather than act as a variable series resistance as the typical linear regulator does, a shunt regulator provides a path to ground for excess voltage (and current) to flow through. This type of regulator is often less efficient than a typical series linear regulator. It is only practical when little power is needed and supplied.

How Switching Voltage Regulators Work

A switching voltage regulator works on a different principle than linear voltage regulators. Rather than acting as a voltage or current sink to provide a constant output, a switching regulator stores energy at a defined level and uses feedback to ensure that the charge level is maintained with minimal voltage ripple. This technique allows the switching regulator to be more efficient than the linear regulator by turning a transistor fully on (with minimal resistance) only when the energy storage circuit needs a burst of energy. This approach reduces the total power wasted in the system to the resistance of the transistor during the switching as it transitions from conducting (very low resistance) to non-conducting (very high resistance) and other small circuit losses. The faster a switching regulator switches, the less energy storage capacity it needs to maintain the desired output voltage, which means smaller components can be used. However, the cost of faster switching is a loss in efficiency as more time is spent transitioning between the conducting and non-conduction states. More power is lost from resistive heating. Another side effect of faster switching is the increase in electronic noise generated by the switching regulator. By using different switching techniques, a switching regulator can: Step down the input voltage (buck topology).Step up the voltage (boost topology).Both step down or step up the voltage (buck-boost) as needed to maintain the desired output voltage. This flexibility makes switching regulators a great choice for many battery-powered applications because the switching regulator can step up or boost the input voltage from the battery as the battery discharges. Was this page helpful? Thanks for letting us know! Get the Latest Tech News Delivered Every Day Subscribe Tell us why! Other Not enough details Hard to understand Submit More from Lifewire Types of Voltage Regulators 5 Applications of Inductors You Should Know What Are Diodes and What Are They Used For? How to Install a Desktop Power Supply How to Manually Test a Power Supply With a Multimeter Can a 12 Volt Car Battery Really Electrocute Someone? How to Use a Power Supply Tester to Test a PSU How to Fix a Stuck Car Window CyberPower CP1500AVRLCD Review What Are the Applications of Capacitors? Power Supply Voltage Tolerances How to Fix a Computer That Turns on but Displays Nothing How to Fix a Computer That Turns On and Then Off How to Size an Uninterruptible Power Supply How Cigarette Lighters Became 12V Accessory Sockets What Are AirPods and How Do They Work? Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. Cookies Settings Accept All Cookies