#060 5V Breadboard Regulator
An LM7805 5V regulated power supply on breadboard-compatible protoboard.
Notes
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;-)
Construction
Sketching a protoboard layout that would work:
Testing - within a few mV of 5V as expected:
Credits and References
- LM7805 datasheet - 5v regulator. Note that other chips in the LM78xx range are available to provide other voltages.
- LEAP#027 LM7805 5V Regulated Supply - related experiment testing the 7805
- LEAP#028 MB102 3.3/5V Breadboard Supply - testing a commercial power supply unit