Per Jessen wrote:
Aaron Kulkis wrote:
Power supplies are generally rated on how much power they consume, not how much they supply.
But when there is a relatively direct connection between the two, what does it matter?
Yes. An 80% efficient 400W power supply is NOT rated to supply 400W of power, consuming 500W. It's rated to CONSUME 400W of power, supplying only 320 W. So, yes, it does matter, because 400W of devices needs a 500W+ power supply.
You're demonstrating that you really don't know enough about this subject to give qualified comments on it. Perhaps if you took some electrical engineering courses, specifically a course on electric power. Impedance matching is a very big issue, as well as Q-factors and other things which all have HUGE impacts on efficiency.
Aaron, I appreciate your comments except when you're BS'ing just for the sake of it. This is not the right list for a discourse on switchmode powersupply design.
I'm just correcting crazy-talk that is 100% false. NO power supply is rated by its output.
In mid 1908s when I worked in electronics for s short while, a switchmode supply could achieve 80% efficiency without any major design ^^^^^^
effort. I'm assuming that this is still possible, even with sub-standard components and designers.
But in a market in which Watts/dollar is the primary means of comparison for most consumers, the uninformed simply by the lowest-priced power-supply that meets whatever they believe to be their system load to be. What this translates into is cheap components (such as +/-20% resistors instead of +/-5% or 1%, and similarly sloppy-tolerance components in other parts of the CONSTRUCTION of the power supply
To get the 80+% efficiency across the board is NOT a trivial thing.
I have to disagree. Even a relatively poor or inexperienced design will achieve that. Aiming at 90% or higher is less than trivial.
Then why so many power supplies that don't meet the 80% across-the-board standard of 80plus.org?
You're really not qualified to advise others on this subject.
Please do tell us exactly why you are qualified to judge that.
I'm an electrical and computer systems engineer. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org