In 4 quick steps, you could create a power supply that is simple and easily mobile, both of which are crucial in the midst of a catastrophe. If you don't understand the basics of electricity, then it might be best to grab a friend who does just in case. In the end, you'll have a power unit that can be relied upon if and when the power goes out.

Step 1: Gather Materials

• 7805 Voltage Regulator IC
• 330k ohm Resistors x 4
• 220k Ohm Resistors x 2
• 82k Ohm Resistors x 2
• 9v Battery
• Battery Snapper
• 2 Pin Connector For Output
• 4 Connected DIP Switches

Step 2: The Circuit

Assemble the components according to circuit Diagram.

This circuit is built around 7805 Voltage Regulator IC. This IC Converts first of all converts 9v to 5v DC.

This 5v Dc is again Converted to 1.5v, 3v, 4.5 by some Resistors.

The 4.5v from 5v is obtained by adding 82 k ohm.

The 3v from 5v is obtained by connecting two 330k Resistors in Series.

1.5 v is obtained by voltage dividing circuit. Where 660k(2 330k in Series) and 524k(2 220k and one 82k in Series) ohm are kept.

Step 3: Soldering

Solder the resistors the way I have shown.

Step 4: Ready to Power

Have you made this pocket-sized power supply? Did it work for you?

Article and Photo Source: Instructables