Here is a 5V power supply circuit using LM 7805 IC. LM7805 is a famous positive voltage regulator IC comes in three terminal provides fixed 5V DC output. This IC has many built in features like internal current limiting, thermal shut down, operating area protection etc. Transformer in this
circuit is 230V AC to 9V 2A DC, output current of this circuit is upto 1A. The IC will become hot during the operation so it is essential to use a good heat sink.