Voltage regulators are designed to maintain and stabilise voltage levels. Regulators are found in most electronic devicesand can be used to step-down and control voltage outputs from a high voltage sourcedissipating excess energy as heat. This is great for applications where you need multiple discrete voltages for different devicesas you can use voltage regulators to step-down from a single higher output source! Voltage regulators can also be used as current limiters in circuitsas they will overheat and shut-down or burn out when their maximum current is exceededhopefully protecting devices down the line.
This is the TO-220 version which means if fits perfectly into breadboards and is great for projects. This voltage regulators also features internal current limitingthermal shut-down protection and a nice clean 4% regulation. It has a voltage drop of ~5Vwhich means the input voltage must typically remain 5V above the output voltage (5V)so you'll need to provide at least 10V's to obtain a clean output. Please also note the current limit of your chosen regulatorthey will burn-out if this current is exceeded.
A common ground is required between the input and the output voltagesand if the regulator is situated more than 25cm (10 inches) away from the power supply you'll need to add capacitors to the input (0.33uf) and output (0.10uf) to filter noise on the line. Both these capacitors can be omitted if you aren't too concerned with how much line noise there is e.g. if you're adding a few LEDs with resistors. Howeverif you're building something like a mobile phone chargeryou'll want a nice clean line so we would recommend including the capacitors!
Please be awarethe higher your input voltage and required output currentthe more heat your regulator will generate. You can use the regulator's datasheetand this online calculator to work out if you need heat-sinking. Howeveras a rule of thumbthe higher the voltage inputthe more likely you will need to use heatsinkingand if it feels too hotit probably is too hot! We stock clip-on TO-220 heat sinks here!
We've also put together a guide on how to use voltage regulators in a circuit!