5V Regulated Power Supply Circuit Diagram

Schematic Diagrams      Comments Off on 5V Regulated Power Supply Circuit Diagram

Simple 5V power supply for digital circuits

This circuit is a small +5V power supply, which is useful when
experimenting with digital electronics. Small inexpensive wall
tranformers with variable output voltage are available from any
electronics shop and supermarket. Those transformers are easily
available, but usually their voltage regulation is very poor, which
makes then not very usable for digital circuit experimenter unless a
better regulation can be achieved in some way.

The following circuit is the answer to the problem. This circuit can
give +5V output at about 150 mA current, but it can be increased to 1 A
when good cooling is added to 7805 regulator chip. The circuit has
overload and thermal protection. The capacitors must have enough high
voltage rating to safely handle the input voltage feed to circuit. The
circuit is very easy to build for example into a piece of veroboard.

Circuit diagram:

5 Volt DC Power Supply Circuit

5 Volt DC Power Supply Circuit Diagram


C1 = 100uF-25V electrolytic capacitor, at least 25V voltage rating
C2 = 10uF-25V electrolytic capacitor, at least 6-16V voltage rating
C3 = 100nF-63V ceramic or polyester capacitor
IC = 7805 regulator IC

IC’s Pinout :

  • Unregulated voltage in
  • Ground (See Diagram)
  • Regulated voltage out

Circuit features:

  • Gives out well regulated +5V output, output current capability of 100 mA
  • Built-in overheating protection shuts down output when regulator IC gets too hot
  • Very simple and easy to build
  • Very stable +5V output voltage, reliable operation
  • Easy to get components, uses only very common basic components
  • Based on datasheet example circuit, I have used this circuit succesfully as part of many electronics projects
  • Part of electronics devices, small laboratory power supply
  • Wide range of input unreglated DC 8-24V power supply
  • Few dollars for the electronics components + the input transformer cost

More output current:

  • If you need more than 150 mA of output current, you can update the output current up to 1A doing the following modifications.
  • Change the transformer from where you take the power to the
    circuit to a model which can give as much current as you need from
    Put a heatsink to the 7805 regulator (so big that it does not overheat because of the extra losses in the regulator)

More output voltages:

If you need other voltages than +5V, you can modify the circuit by
replacing the 7805 chips with another regulator with different output
voltage from regulator 78xx chip family. The last numbers in the the
chip code tells the output voltage. Remember that the input voltage muts
be at least 3V greater than regulator output voltage ot otherwise the
regulator does not work well.