How To Change AC to DC

AC adapters transform power to a usable direct current.

Converting an alternating current to direct current can be accomplished by devising a small piece of equipment. Most laptop computers are sold with an AC converter that transforms alternating current from a power outlet into a direct current before it reaches the computer. Nearly every other device in your home that gets plugged in to an outlet transforms alternating current to direct current as well. These adapting devices rely on transformers, the same technology that changes voltages for transmission from power plants to residential buildings.

Things You'll Need

• AC adapter
• 2-pronged plug

Instructions

1. Plug the 2-pronged plug into a wall outlet. This will deliver 120 volts with a current traveling at a frequency of 60 hertz to the adapter.

2. Plug the other end of the wall cord into the adapter unit, and plug the adapter unit into your device. You may notice the end of the cord being plugged into your device probably has a single prong rather than a pair, like what gets plugged into the wall.

3. Understand what happens inside the power converter. Two wires are coiled around iron bars, creating an electric field. The output voltage will be reduced by a factor of the ratio of the number of windings around the first iron bar to the number of windings around the second iron bar.

4. Rectifying diodes transform the flow into a one-way current. Two diodes should point toward the output of the converter. Since these rectifiers only allow current to flow in one direction, they effectively create a direct current.

References

• PR Log: How Does a Laptop AC Adapter Work?
• Physics Tutorials: Alternating Current and Direct Current and Diodes