Why do computers use switching power supplies instead of linear supplies?
Switching power supplies can use smaller reactive components (such as the transformer, inductors, and capacitors) because a higher frequency is used. Linear supplies supplies have the line frequency (or a low multiple, such as twice the line frequency) on the reactive components, so larger, more expensive, parts are required. Second, regulated switching supplies are more efficient than regulated linear supplies. The lower efficiency of linear supplies means they will waste more power and convert that wasted power to heat. Besides the problem of wasting power, costly components (heat sinks, fans, etc.) must now be devoted to dissipating that heat. Linear supplies are most economical at low powers (such as for running calculators and small devices) due to their simplicity. Switching supplies are more cost effective at the power levels used in computers. • Describe the differences between a standby and on-line UPS. With an on-line UPS, the load is constantly being driven by the inverter w
