Power Conversion Electronics
pg
I am amaze with the PFC (Power Factor Correction) rating of over 0.96,
which, according to some indicators, means it's 96% efficient. (4%
wastage as heat).
Since it's a new unit I dare not to open up the PSU to see what type
of electronics they are using.
So I post the question here ----
Can anyone tell me what type of Power Conversion Electronic Devices
they use in those high PFC rating PSU?
Thank you all !!!
Ken
wrote:
> I just purchase a Silverstone Power Supply Unit (PSU) for my PC.
>
> I am amaze with the PFC (Power Factor Correction) rating
> of over 0.96, which, according to some indicators,
> means it's 96% efficient. (4% wastage as heat).
PFC and efficiency are not the same thing.
http://en.wikipedia.org/wiki/Power_factor_correction
http://en.wikipedia.org/wiki/Energy_conversion_efficiency
Eeyore
pg wrote:
> I just purchase a Silverstone Power Supply Unit (PSU) for my PC.
>
> I am amaze with the PFC (Power Factor Correction) rating of over 0.96,
> which, according to some indicators, means it's 96% efficient. (4%
> wastage as heat).
Incorrect. It has nothing to do with efficiency.
> Since it's a new unit I dare not to open up the PSU to see what type
> of electronics they are using.
>
> So I post the question here ----
>
> Can anyone tell me what type of Power Conversion Electronic Devices
> they use in those high PFC rating PSU?
Download an application note say from I.R.
Graham
pg
Many thanks for the info !! :)
david
0.96 power factor does not mean 96% efficient. But, to answer your
question, active power factor correction means that the front end of the
power supply tries to keep the phase between the voltage and current
waveforms as small as possible.
MooseFET
It also tries not to draw any current at harmonics. It is unfortunate
that one term is now used for two effects but we are stuck with it.
Tim Williams
> It also tries not to draw any current at harmonics. It is unfortunate
> that one term is now used for two effects but we are stuck with it.
Displacement Factor is the fudamental only.
Tim
UCLAN
Please do not confuse Power Factor Correction (PFC) with power supply
efficiency. They are two separate items. PFC can be either active or
passive, but usually alters the highly capacitive input of SMPSs.
Google "PFC".
Phil Allison
"UCLAN"
> Please do not confuse Power Factor Correction (PFC) with power supply
> efficiency. They are two separate items.
** OK so far.
> PFC can be either active or passive,
** Hmmmm...
> but usually alters the highly capacitive input of SMPSs.
** TOTAL BOLLOCKS !!!
They are not capacitive, there is no phase angle.
Active PFCs correct WAVEFORM distortion.
...... Phil
John Larkin
Take you meds and lie down for a while. What he said was perfectly
reasonable.
John
Phil Allison
"John Larkin"
"Phil Allison"
>>"UCLAN"
>>
>>> Please do not confuse Power Factor Correction (PFC) with power supply
>>> efficiency. They are two separate items.
>>
>>** OK so far.
>>
>>> PFC can be either active or passive,
>>
>>** Hmmmm...
>>
>>> but usually alters the highly capacitive input of SMPSs.
>>
>>
>>** TOTAL BOLLOCKS !!!
>>
>> They are not capacitive, there is no phase angle.
>>
>> Active PFCs correct WAVEFORM distortion.
>
>
> Take you meds and lie down for a while.
** Drop dead.
> What he said was perfectly reasonable.
** It was totally FALSE , you insane fuckhead.
..... Phil
Nobody
>> I just purchase a Silverstone Power Supply Unit (PSU) for my PC.
>>
>> I am amaze with the PFC (Power Factor Correction) rating of over 0.96,
>> which, according to some indicators, means it's 96% efficient. (4%
>> wastage as heat).
>
> Incorrect. It has nothing to do with efficiency.
It has *some* effect upon efficiency, but not much.
Nobody
> I just purchase a Silverstone Power Supply Unit (PSU) for my PC.
>
> I am amaze with the PFC (Power Factor Correction) rating of over 0.96,
> which, according to some indicators, means it's 96% efficient. (4%
> wastage as heat).
As others have already pointed out, 0.96 power factor doesn't mean 96%
efficient.
Power factor does have a slight impact upon efficiency, as a low power
factor increases the energy wasted in the power lines, but this is small
compared to the energy actually used by the supply.
> Since it's a new unit I dare not to open up the PSU to see what type
> of electronics they are using.
>
> So I post the question here ----
>
> Can anyone tell me what type of Power Conversion Electronic Devices
> they use in those high PFC rating PSU?
Active PFC involves using a boost converter whose current draw is
sinusoidal and in phase with the voltage.
For more detail than you probably wanted to know, see:
pg
Thanks a lot for the link !!
UCLAN
>>Please do not confuse Power Factor Correction (PFC) with power supply
>>efficiency. They are two separate items.
>
> ** OK so far.
Gee, thanks. [Red flag warning!!!]
>>PFC can be either active or passive,
>
> ** Hmmmm...
Careful, a hint of ignorance is showing.
>>but usually alters the highly capacitive input of SMPSs.
>
> ** TOTAL BOLLOCKS !!!
>
> They are not capacitive, there is no phase angle.
And it's finally out. He's a total loon.
There is a big 400vdc capacitor (or two 200vdc caps in series) just after
input rectifiers on the AC input. Note C5 and C6 on:
http://www.pavouk.org/hw/en_atxps.html
They charge to the peak value of the input
AC voltage, or 1.414 times the RMS value. Since the cap(s) draw their maximum
current when at lowest charge (zero cross-over point), and draw their least
amount of current when charged to their highest point, the current waveform
*leads* the voltage waveform by 90 degrees. [Maximum current is at the same
time as minimum voltage; minimum current is at the same time as maximum voltage.]
Phil Allison
"UCLAN" = the Original Monkey's Uncle.
>
> Phil Allison wrote:
>
>>>Please do not confuse Power Factor Correction (PFC) with power supply
>>>efficiency. They are two separate items.
>>
>> ** OK so far.
>
> Gee, thanks. [Red flag warning!!!]
>
>>>PFC can be either active or passive,
>>
>> ** Hmmmm...
>
> Careful, a hint of ignorance is showing.
>
>>>but usually alters the highly capacitive input of SMPSs.
>>
>> ** TOTAL BOLLOCKS !!!
>>
>> They are not capacitive, there is no phase angle.
>
> And it's finally out. He's a total loon.
** This arrogant IMBECILE is about to get a lesson !!!
> There is a big 400vdc capacitor (or two 200vdc caps in series) just after
> input rectifiers on the AC input.
** And because they are * AFTER * the rectifiers there is NO cap
reactance or phase angle effects involved.
> They charge to the peak value of the input
> AC voltage, or 1.414 times the RMS value.
** The caps can only draw current when the diodes are forward biased and
cannot pass any current back to the supply.
Negates all capacitive reactance effects.
> Since the cap(s) draw their maximum
> current when at lowest charge (zero cross-over point),
** 100% FUCKING WRONG !!!!!!!!!!!
The caps can only draw charging current when the AC supply voltage is
greater than the voltage already on the cap - so ( aside from the very
first cycle ) they charge at AC voltage peaks ONLY !!!!!!!!
> and draw their least amount of current when charged to their highest
> point,
** Insane CRAP !!!!!!!!!!!!!!!
Even one moment's intelligent thought shows that simply CANNOT be true.
> the current waveform
> *leads* the voltage waveform by 90 degrees.
** Absolute BOLLOCKS !!!
Max current draw **coincides** with peak AC voltage - there is ZERO
phase angle.
Time for you to go play with the demented Orang-utans
- DICKHEAD !!
..... Phil
kony
<phila...@tpg.com.au> wrote:
>
>"UCLAN" = the Original Monkey's Uncle.
>>
>> Phil Allison wrote:
>>
>>>>Please do not confuse Power Factor Correction (PFC) with power supply
>>>>efficiency. They are two separate items.
>>>
>>> ** OK so far.
>>
>> Gee, thanks. [Red flag warning!!!]
>>
>>>>PFC can be either active or passive,
>>>
>>> ** Hmmmm...
>>
>> Careful, a hint of ignorance is showing.
>>
>>>>but usually alters the highly capacitive input of SMPSs.
>>>
>>> ** TOTAL BOLLOCKS !!!
>>>
>>> They are not capacitive, there is no phase angle.
>>
>> And it's finally out. He's a total loon.
>
>
> ** This arrogant IMBECILE is about to get a lesson !!!
>
>
Maybe, but you are still a total loon (!!!)
>> Since the cap(s) draw their maximum
>> current when at lowest charge (zero cross-over point),
>
>
>** 100% FUCKING WRONG !!!!!!!!!!!
When one uses this many apostrophies, it is customary to ask
Vanna for a vowel and pay for each. You have not done so,
and so it is detracting from your attempted point.
>
>The caps can only draw charging current when the AC supply voltage is
>greater than the voltage already on the cap - so ( aside from the very
>first cycle ) they charge at AC voltage peaks ONLY !!!!!!!!
Ok !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
>Time for you to go play with the demented Orang-utans
Wait, are you saying we now have a petting zoo?
cool!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Which cage are you in, I will stop by and throw you a
peanut. And some lithium.
Phil Allison
"kony"
** No man is an island ......
.... Phil
Michael A. Terrell
kony wrote:
>
> Which cage are you in, I will stop by and throw you a
> peanut. And some lithium.
Throw him some Dilitium. His mind needs a recharge. ;-)
--
You can't have a sense of humor, if you have no sense!
UCLAN
> ** This arrogant IMBECILE is about to get a lesson !!!
I suggest you do a little reading. Start with:
http://www.fairchildsemi.com/an/AN/AN-42047.pdf
Until then, I suggest you get back on your meds - quickly.
Eeyore
Nobody wrote:
Yes, it decreases the overall efficiency of the PSU but increases the
efficiency of the grid !
Graham
Eeyore
Tim Williams wrote:
Never heard that term. Can you explain ?
Graham
Tim Williams
wrote:
> > Displacement Factor is the fudamental only.
>
> Never heard that term. Can you explain ?
http://en.wikipedia.org/wiki/Power_factor#Non-sinusoidal_components
It's mentioned in a paragraph or two.
Apparently it's a fairly new term, IEEE or NEMA probably have
something about it.
The power meters in the power electronics lab here read three phase V,
I, P, Q, PF, DF, etc. directly. Scary expensive Fluke 434.
Tim
Phil Allison
"UCLAN" = Monkey's Uncle
** This arrogant IMBECILE has had his lesson.
But he didn't learn anything -
cos he is a congenital fuckwit.
...... Phil
CBFalconer
> "Phil Allison" <phila...@tpg.com.au> wrote:
>
... snip ...
>
>> ** TOTAL BOLLOCKS !!!
>>
>> They are not capacitive, there is no phase angle.
>>
>> Active PFCs correct WAVEFORM distortion.
>
> perfectly reasonable.
Also, kindly give a complete description about how you determine
that an isolated waveform is distorted?
--
[mail]: Chuck F (cbfalconer at maineline dot net)
[page]: <http://cbfalconer.home.att.net>
Try the download section.
CBFalconer
> "John Larkin"
>
... snip ...
>
>> Take you meds and lie down for a while.
>
> ** Drop dead.
>
>> What he said was perfectly reasonable.
>
> ** It was totally FALSE , you insane fuckhead.
I suspect he failed to follow your advice, above. It doesn't
appear to have improved his language, either.
Eeyore
Tim Williams wrote:
> On Apr 27, 1:44 pm, Eeyore <rabbitsfriendsandrelati...@hotmail.com>
> wrote:
> > > Displacement Factor is the fudamental only.
> >
> > Never heard that term. Can you explain ?
>
> http://en.wikipedia.org/wiki/Power_factor#Non-sinusoidal_components
>
> It's mentioned in a paragraph or two.
A search couldn't find it.
Graham
Franc Zabkar
finger to keyboard and composed:
>There is a big 400vdc capacitor (or two 200vdc caps in series) just after
>input rectifiers on the AC input. Note C5 and C6 on:
>
>http://www.pavouk.org/hw/en_atxps.html
>
>They charge to the peak value of the input
>AC voltage, or 1.414 times the RMS value. Since the cap(s) draw their maximum
>current when at lowest charge (zero cross-over point), and draw their least
>amount of current when charged to their highest point, the current waveform
>*leads* the voltage waveform by 90 degrees. [Maximum current is at the same
>time as minimum voltage; minimum current is at the same time as maximum voltage.]
As much as I dislike the man, he's right.
Look at Fig 6 on page 2 of the application note you linked to
elsewhere in this thread.
PA could easily put at end to this argument by enlightening everyone
with his own example ...
http://groups.google.com/group/aus.electronics/msg/fe5b24eacbfeb277?dmode=source&hl=en
... but instead he chooses to elevate himself by demeaning others.
- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
Tim Williams
wrote:
> > It's mentioned in a paragraph or two.
>
> A search couldn't find it.
Second paragraph from link,
"In circuits having only sinusoidal currents and voltages, the power
factor effect arises only from the difference in phase between the
current and voltage. This is narrowly known as "displacement power
factor". The concept can be generalized to a total, distortion, or
true power factor where the apparent power includes all harmonic
components."
Tim
Eeyore
Franc Zabkar wrote:
> On Sun, 26 Apr 2009 22:48:56 -0700, UCLAN <inv...@invalid.com> put
> finger to keyboard and composed:
>
> >There is a big 400vdc capacitor (or two 200vdc caps in series) just after
> >input rectifiers on the AC input. Note C5 and C6 on:
> >
> >http://www.pavouk.org/hw/en_atxps.html
> >
> >They charge to the peak value of the input
> >AC voltage, or 1.414 times the RMS value. Since the cap(s) draw their maximum
> >current when at lowest charge (zero cross-over point), and draw their least
> >amount of current when charged to their highest point, the current waveform
> >*leads* the voltage waveform by 90 degrees. [Maximum current is at the same
> >time as minimum voltage; minimum current is at the same time as maximum voltage.]
>
> As much as I dislike the man, he's right.
He is. Actually, from modelling, I've found a big hulky inductor between the rectifier and
storage caps is pretty good at correcting harmonics. Trouble is, they're big, heavy and
expensive.
Sadly active PFC produces even more RF 'hash' that needs to be dealt with.
> Look at Fig 6 on page 2 of the application note you linked to
> elsewhere in this thread.
>
> PA could easily put at end to this argument by enlightening everyone
> with his own example ...
>
> http://groups.google.com/group/aus.electronics/msg/fe5b24eacbfeb277?dmode=source&hl=en
>
> ... but instead he chooses to elevate himself by demeaning others.
Sadly so.
Graham
Eeyore
Tim Williams wrote:
You said initially "displacement factor" without the power hence the
absence of hits.
It would be good if phase only related PFC ( motors etc ) could be
better distinguished from harmonics. The average bod gets confused about
the whys and wherefores of the two.
Graham
Sylvia Else
> On Sun, 26 Apr 2009 22:48:56 -0700, UCLAN <inv...@invalid.com> put
> finger to keyboard and composed:
>
>> There is a big 400vdc capacitor (or two 200vdc caps in series) just after
>> input rectifiers on the AC input. Note C5 and C6 on:
>>
>> http://www.pavouk.org/hw/en_atxps.html
>>
>> They charge to the peak value of the input
>> AC voltage, or 1.414 times the RMS value. Since the cap(s) draw their maximum
>> current when at lowest charge (zero cross-over point), and draw their least
>> amount of current when charged to their highest point, the current waveform
>> *leads* the voltage waveform by 90 degrees. [Maximum current is at the same
>> time as minimum voltage; minimum current is at the same time as maximum voltage.]
>
> As much as I dislike the man, he's right.
>
> Look at Fig 6 on page 2 of the application note you linked to
> elsewhere in this thread.
It does show that the current leads - look at how it's not positioned
symmetrically about the 90 degree point, for example. It's not a 90
degree lead, of course, but it's still a lead.
Mind you, I think the graph is wrong. When it's flowing, the current
into a capactor should be proportional to the rate of change of voltage.
So you should see a rapid rise once the input voltage goes above that
already on the capacitor, followed by a progressive reduction towards
zero (plus the load current) at the voltage peak. I suppose you'd get
something closer to what's shown if there were an inductor in series
with the supply.
Sylvia.
Nobody
> Mind you, I think the graph is wrong. When it's flowing, the current
> into a capactor should be proportional to the rate of change of voltage.
> So you should see a rapid rise once the input voltage goes above that
> already on the capacitor, followed by a progressive reduction towards
> zero (plus the load current) at the voltage peak.
That's what you get if the voltage ripple is large: a reverse sawtooth.
But if the voltage ripple is small, you need to allow for the fact that
a diode isn't a switch. Conduction will only start to occur at the very
peak of the voltage waveform, where dv/dt is small, so the transition
through the knee of the characteristic curve will be slow.
By the chain rule, d(i(v))/dt = di/dv*dv/dt. As the voltage increases to
the point where the characteristic curve becomes steep, dV/dt falls
even faster, so the increasing di/dv is counteracted by decreasing dv/dt.
> I suppose you'd get
> something closer to what's shown if there were an inductor in series
> with the supply.
There's always some parasitic inductance, if only from the wires.
More significantly, linear supplies have the leakage inductance of the
transformer's secondary, and any switching supply will have an EMI filter.
Even with zero parasitic inductance, there's still the capacitor's ESR; if
you model the capacitor as a series R-C, the capacitor will still be
charging at (and slightly after) the voltage peak.
Franc Zabkar
>Franc Zabkar wrote:
>> On Sun, 26 Apr 2009 22:48:56 -0700, UCLAN <inv...@invalid.com> put
>> finger to keyboard and composed:
>>
>>> There is a big 400vdc capacitor (or two 200vdc caps in series) just after
>>> input rectifiers on the AC input. Note C5 and C6 on:
>>>
>>> http://www.pavouk.org/hw/en_atxps.html
>>>
>>> They charge to the peak value of the input
>>> AC voltage, or 1.414 times the RMS value. Since the cap(s) draw their maximum
>>> current when at lowest charge (zero cross-over point), and draw their least
>>> amount of current when charged to their highest point, the current waveform
>>> *leads* the voltage waveform by 90 degrees. [Maximum current is at the same
>>> time as minimum voltage; minimum current is at the same time as maximum voltage.]
>>
>> As much as I dislike the man, he's right.
>>
>> Look at Fig 6 on page 2 of the application note you linked to
>> elsewhere in this thread.
>
>It does show that the current leads - look at how it's not positioned
>symmetrically about the 90 degree point, for example. It's not a 90
>degree lead, of course, but it's still a lead.
A bigger capacitor would result in less ripple, which means less lead.
If you were relying on intuition alone, you would expect that the PF
would move closer to unity. In fact the PF actually becomes worse.
See the calculations in Phil's example.
Sylvia Else
With a larger capacitor, you get less lead, but higher instantaneous
currents. My intuition would be that the net result is far from obvious.
However, the higher current for shorter periods means higher harmonic
currents, which don't contribute to the power, so it wouldn't surprise
me that the PF would go down.
Sylvia.