Voltage regulator

The term 'voltage regulator' refers to any device that keeps a constant voltage going for a range of loads. See the Wikipedia article on voltage regulators for a reasonably detailed description. Generally in electronics, regulators come in the form of integrated silicon chips. The most common variety are 'linear regulators'.

Regulators are used to take a power supply that provides unreliable / wobbly / too-high voltage (e.g. a cheap-and-cheerful battery-eliminator power brick), and shaves off a bit at the top to produce a steady, smooth, controlled output voltage.

Some common linear regulators

The following is a list of some of the more commonly used regulators. To choose a suitable regulator, you'll need to know what voltage output you need, and roughly how much current you need to draw from it. Other considerations include how you're going to mount it, and whether you have enough supply voltage to make it work properly.

• L7805: 5V output, 1.5A current capacity, 3-pin TO-220 package

• L78L05: 5V output, 100mA current capacity, 3-pin TO-92 package

• LM317T: 1.25V-37V adjustable output, 1.5A current capacity, 3-pin TO-220 package

• LM317K: 1.25V-37V adjustable output, 5A current capacity, 2-pin+case TO-3 package

From left to right: TO-3 package, TO-220 package, TO-92 package

Further Reading & Related Articles

• Common Failures of Regulators
• Using a Fixed Regulator as an Adjustable Regulator
• Adjustable Regulators
• How to use a linear regulator to make a power supply

This page is an Article on bildr. Articles are pages that define or explain a concept, method, or generic item.