A Switch mode power supply works on the principle of superior efficiency. The benefits of the switch mode is its lighter weight and reduced size. Saving weight and reducing size is crucial to lower shipping costs when they are distributed improving.
The Switch Mode Power is designed to be a more efficient Unit running much cooler and draws less current which is beneficial all round.
A switch-mode power supply creates DC from the AC mains power using transistor switches and other components. As we know from experience of older power adapters, amps of high power tend to be quite heavy. One of the main factors in the increased weight is the iron in the transformer.
Older designed transformers had to be large to avoid saturation at the 50hz or 60hz frequency of the AC supply. That issue resulted in poor performance at that lower frequency range..
The switch mode power supply amplifier wastes very little power in the form of heat. Most of the incoming AC power is converted to amplifier output power.
How does that happen? Well, remember from Ohm’s Law that voltage times current equals power. When the voltage or current in a device is zero, so is the power.
The switching or “chopping” transistors produce no current when they are switched off, and produce no voltage when switched on, so they generate very little power as heat. This results in a highly efficient power supply.
Therefore we have learned that the switch mode power adapter is the primary choice for most manufacturers. There is but one disadvantage for the end user. The switch mode power works on more complicated circuitry. If they fail there is not much likelihood of repair due to the specialized nature and costs. Most quality made PSU’s are very reliable and can last for years so a small disadvantage for a superior product.
Thanks to switching power supplies, we can get clean efficient power for our Electronic items in a light and efficiently designed package.