This project uses a 7805 voltage regulator to regulate voltage to 5volts. There is a switch to turn power to the circuit on and off and an LED as reference. The power connected to the power plug should be at least 7v.

Use a 7805 voltage regulator, two 10 µF capacitors, a power plug or battery (minimum 7 volts), a switch, an LED and a 220Ω resistor.