| Power supply is generally referred to as a source | | | | second. There are several household in US that |
| of electrical power. It is a device or system that | | | | are wired for high power devices and operate at |
| supplies electrical or other forms of an energy to | | | | 240 VAC. The major benefit is that 240 VAC |
| an output load or group of loads and is known as | | | | needs only half the current of 120 VAC for the |
| power supply unit or PSU. The electricity primarily | | | | similar power consumption which in turn curtails |
| flows in two ways, namely AC or alternating | | | | resistive power losses in the wires that deliver |
| current and DC or direct current. They are in-fact | | | | the current. |
| a movement of electrons along the conductor. | | | | Why AC power supply is preferred over DC: |
| The only variation among AC and DC lies in the | | | | Alternating current posses the potential for large |
| direction, wherein the AC keeps the moving | | | | scale. |
| electrons in a switching manner, on the other | | | | They can be conveniently and cheaply produced |
| hand DC is in a steady single track. | | | | than DC potentials. |
| AC power supply is mainly used for long distance | | | | DC is still the ideal choice in the areas where the |
| power transmission to different power companies. | | | | requirements are relatively lower such as, |
| As high voltages are required to fill the | | | | flashlights, mobile systems and car but commercial |
| transformer of those companies, AC power | | | | power plants still produce AC as they are quite |
| supply is needed where as, DC provide current on | | | | cheaper and reliable. |
| a small-scale basis. | | | | Alternating current can be transformed into higher |
| AC power is nowadays used all over the world. | | | | or lower potentials and even a transformer can |
| AC power in reality reverses direction. In US, the | | | | enhance or reduce AC power supply to whatever |
| current makes a complete cycle 60 times a | | | | value is needed for the job. |