So I bought a couple of switching power supplies for a project of mine and I am currently recalculating my actual power usage out of my wall socket to figure out how to distribute power. I have made sure that my power supplies will never exceed 90% of its capacity, but the normal operating will be around 40-50%.
I tried to calculate the values and compare them with the ratings of my supplies and they are way more off that I anticipated. Example:
I have a 5V power supply that can deliver 20 amps for DC output. My AC input rating for this supply says: 230V (170-264V) 1.5A. However my calculations for 240V is 0.416A. So the theoretical and stated power usage is 1 amp off. I figured there would be some waste but not that much.
- Are my calculations way off?
- Are the producer of the power supply just overly careful?
- Or does the power supply really waste the much
energy in the conversion?
- Does the power supply have a poor power factor ?
- Is the part load efficiency poor ?