Linear power supply runs hot AF!

[elan120]

2 hours ago, sdmarquart said:

I guess I need a better education of LPS in layman’s terms. I google and it says it converts AC to DC and how they run warm and need heat sinks. Also very inefficient but are used for audio products as they are very low noise.

 

That’s great but what does it mean. Why is the damn thing so hot?

One of the key is efficiency, and it is calculated as:

 

                        Output power

Efficiency =  ------------------------

                         Input power

 

Using an example, if the power supply has 50% efficiency and the requested load power is 100W, then the total input power required to provide this 100W of output would be 200W.  The other 50% of input power (100W) is wasted, and most of this wasted power will become heat that has to be dissipated.

 

Better linear power supply will have better efficiency, design, parts, and workmanship so they will run at lower temperature.  Meanwhile, power supply will run hotter when pushing closer to the upper limit of their output.

 

In general, there are many possible factors that could drive a power supply to run hot, and when the power supply gets too hot, it could affect their overall service life.

 

Hope this helps a bit...