How To use voltage regulators

Basic electronics part 6

This page is about voltage regulators, check out the main index for the rest.

Below is a picture of a 5 volt voltage regulator, it is marked ‘7805’. This will allow you to get a constant 5 volts to power devices that need it such as your PICAXE Micro controller. They also come in other voltage ratings, and they have different current rating too, so check you have the right device for your project.

They have three legs – an input, an output, and a ground/zero volt pin. You should check the datasheet to find out which is which, and typically wire them as follows. In some cases you will need two capacitors which vary in value depending on the current draw – although these are typically required when the power comes from a transformer linked to the mains/outlet power, to suppress interference.

Note that the input is normally for up to about 30 volts DC only, although you should check the specification for the device that you buy.