Power supply for electronics projects

Power supply for electronics projects, In this article I have discussed very famous regulator which use as a power supply in many electronics projects, microcontrollers based projects and embedded system projects. This topic is especially for engineering students who can not purchase expensive power supplies for learning electronics and to use power supplies in their electronics projects. You have came across many power source options while making any project. For example, you are working on a project in which you are using different integrated circuits, semi conductor devices and relays etc. All these components need different voltage power supply levels to perform specific function. For example, you are using AND gate IC in your project, To use this IC you need 5 volt power supply for this IC. I have discussed following regulator and circuit diagrams are also given below:

  • 7805 voltage regulator
  • 7809 voltage regulator
  • 7812 voltage regulator

78XX series of regulators by fairchild are very popular voltage regulators used in many electronics and embedded system projects. All voltage regulators of 78XX can deliver up to 1 ampere current.In 78XX series 78 represents maximum current handling capability which is up to 1 ampere. But proper heat sink should be used with these regulators for its up to 1 ampere.In 78XX series, XX represents voltage output of these voltage regulators. In 7805 voltage regulator, 05 means voltage output of its regulator is fixed 5 volt. Similarly last two digits of 7809 and 7812 represent output voltage of these regulators. In this article I have discussed only three voltage regulators of 78XX series. But full list of 78XX series of regulators is given below:

7805, 7806 7809, 7810, 78012, 7815 7818, 7824 voltage regulators with maximum current rating of 1 Ampere.

5,9 and 12 volt and 1 Ampere power supplies circuit description :

Circuit diagram of five, nice , twelve volt and 1 ampere power supplies are given below. Input to this circuit is 220 volt AC power supply. 220 to 12 volt Transformer is used to step down AC voltage from 220 volt AC to 12 volt AC. Full bridge rectifier is used to convert AC voltage in DC pulsating voltage. At the output of bridge rectifier, electrolytic or polar 100uf/25 volt capacitor is used to convert pulsating output voltage into constant DC voltage. After 100uf polar capacitor, voltage regulators 7805, 7809 and 7812 is used for fixed regulated output voltage. .1uf capacitor is used at the output of these voltage regulators to avoid voltage fluctuations at output. Circuit diagrams of all power supplies are given below.

Circuit diagram of 5 volt and 1 Ampere power supply:


Circuit diagram of 5 volt and 1 Ampere power supply

Circuit diagram of 9 volt and 1 Ampere power supply :


Circuit diagram of 9 volt and 1 Ampere power supply

Circuit diagram of 12 volt and 1 Ampere power supply :

Circuit diagram of 12 volt and 1 Ampere power supply

If you are using a battery source instead of AC power supply as a input, then you have no need to use step down transformer, full bridge rectifier and 100uf polar capacitor. If you still feel any problem while making any above power supply , let me know with your comments. Share this article with your friends. thanks :

4 thoughts on “Power supply for electronics projects”

  1. please help me im 300w digital power supply, and it mist have a pic and lcd, my problem in the program please help me with the program that will display the output voltage when you adjust the potentiometer.


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