An LM7805-based 5V regulated power supply for use in breadboard projects.
See LM7805 5V Regulated Supply for a more detailed investigation of the 7805 voltage regulator.
The LM7805 provides regulated 5V, ideal when current requirements are moderate (up to 1A with heatsink).
This project puts a 5V regulated supply on a protoboard that is designed to plug into a standard breadboard with power rails.
It includes high and low frequency smoothing capacitors, and a master power switch and LED power indicator.
The LED indicator is provided on the regulated supply-side. The 3mm green LED has a forward voltage drop of about 2.2V, so a 1kΩ current-limiting resistor was selected to keep current draw approx 2.8mA.
Given that commercial units can be obtained for as low as 0.80USD (with free shipping!), I'm not sure if I saved any money. But it is more satisfying this way;-)
- LM7805 datasheet - 5v regulator. Note that other chips in the LM78xx range are available to provide other voltages.
- LM7805 5V Regulated Supply - related LittleArduinoProjects experiment testing the 7805
- MB102 3.3/5V Breadboard Supply - testing a commercial power supply unit