I am having a meltdown with a Chinese supplier at the moment and hope dearly that someone can help.
I have an LED driver that is in my mind 28.8W. The output of the driver is 48 V @ 600 mA (48 V x 0.6 A = 28.8 W).
I was however talking to the Chinese supplier who tells me this is a 32.72W driver.
They are justifying this by quoting me P=U·I/efficiency formula (48 · 0.6 / 0.88 = 32.72).
Now what I can't understand is how a driver that puts out only 28.8 W by definition of Ohms law can this be then considered 32.72 W by terms of this formula regarding efficiency? Surely this is simply not possible?
I have gone around in circles trying to get my head around it but can't seem to get past the fact this won't power 30W of LEDs.
Can anyone explain this to me or are they trying to pull the wool over my eyes?
Thanks Guys really impressed with you responses and you have confirmed what I suspected. Essentially he trying to sell the input power as output power, which is what I thought. Absolutely ludicrous.
@ Marcus I think you are absolutely right need to nail down specs before I even have a discussion with these jokers. Unfortunately I buying off the shelf and not having anything specifically tailored. I am committed to the purchase unfortunately luckily it doesn't actually matter for the project but lesson learnt.
Out of interest are there any EU or US conventions of directives for the labelling of Power supplies for output power rather than consumption?