Powering Your PC: Truths and Misconceptions
A Guide To Power Supplies

Linear vs Switching Power Supplies:

Here's a quick overview when comparing linear & switching power supply technology. It becomes easy to see why a PC could not use a linear power supplies as it would require its own tower chassis weighing a couple hundred pounds!

Linear Power Supplies²:

• Large transformers required, linear power supplies are generally heavy (as a general rule of thumb, a 16V-output linear power supply weighs about one pound per ampere)
• Because the power transistor operates in its linear region, and all the output current must pass through it, it requires large heat sinks to dissipate energy loss
• Power efficiency around 50%

Switching power supplies²:

• Higher production costs compared to linear power supplies
• Lighter and smaller than their linear counterparts
• Switching power supplies are about 70%-90% efficient