How to measure "real" power consumption on PSU with APFC?

[OwenBurnett]

Hi,
I read several times that the APFCircut in PSUs screws up ordinary wattage measurements.
So my question is what do I need to measure the real power consumptions?
Does the above meant effect affects the Amperage measurements on decent multimeter?

[jonnyGURU]

As previously stated, I measured some of the units that were giving me problems with a decent multimeter and I still got the same results. :(

Not sure how to fix this unless we could put some sort of "barrier" between the load and the source. Unfortunately, any kind of barrier would cause some in-efficiency and may produce inaccurate numbers in the other direction.

[Per Hansson]

jonnyGURU; Did you try chopping of the active wire going to the PSU and connecting a Digital Multimeter there to measure the amperage?

And what did the PSU manufacturers respond?

[jonnyGURU]

jonnyGURU; Did you try chopping of the active wire going to the PSU and connecting a Digital Multimeter there to measure the amperage?

The "active wire?"

[SnooP]

jonnyGURU; Did you try chopping of the active wire going to the PSU and connecting a Digital Multimeter there to measure the amperage?


Hmm a little dangerous :fire::eek:

The "active wire?"

he's referring to ripping up a power lead and splicing the multimeter inline with it i'd guess to measure amps.

[jonnyGURU]

Ah.. no. I'm clamping.

But the meters don't use that method and I'm getting the same results.

[Per Hansson]

Well, it would just be one additional way to check...

Since the current must go through the multimeter it would suprise me if it did not report correctly, tho I guess anything is possible

[jonnyGURU]

That's my point. The meters I use actually ARE in line with the power input. It's only when I used the DMM that I had clamped. I can test with the DMM in line too, of course.