POWER GAMES:Servo Stabilizer,CVT or Online UPS?
- Thread starter ajay124
- Start date
Thad E Ginathom
Well-Known Member
Thanks to those who have cleared up my serious misunderstanding on how much protection is afforded by an online UPS.
Maybe I'm just as wrong about the crystals!
Maybe I'm just as wrong about the crystals!
What I understand Thad is saying (which I also think is true) is that in an online UPS, pure sinewave power of 60 cycles and constant 230 volts sans all EMI second harmonics etc is regenerated and outputted by drawing current solely from the battery but you seem to indicate that 'differential power' is drawn from batteries to cater to low / fluctuating voltage being received from mains.
Is that so? How does this work?
Thad E Ginathom
Well-Known Member
The selling point of an online UPS is zero-time switchover. There is no switchover, as the batteries are permanently connected to the output.
I had always imagined a simple flow:
AC -->converter-->Battery-->converter-->AC
I had imagined that isolation was a by-product advantage of this.
Taking a look at the circuit diagram on p2 of this link (from earlier in the thread) indicates that things are not so simple.
A site I was browsing from another link on this (I think) thread makes the point that there are no absolute definitions. I guess there may be other implementations.
) or aura or chakras. I'm still sceptical.
I had always imagined a simple flow:
AC -->converter-->Battery-->converter-->AC
I had imagined that isolation was a by-product advantage of this.
Taking a look at the circuit diagram on p2 of this link (from earlier in the thread) indicates that things are not so simple.
A site I was browsing from another link on this (I think) thread makes the point that there are no absolute definitions. I guess there may be other implementations.
Copper is a conductive substance: so, if I put a chunk by my distribution box, it will affect the current? I have known a number of similar suggestions, and known people who tried them, in the belief that it would give some relief to electrical stresses caused either to themselves or to their equipment. I never saw it justified, and certainly not technically. Given that I am not a materialist, I do not reject something that might affect the finer levels of a human being, just because science cannot verify that those levels even exist --- but my hifi was born of scientists. It has no soul (woops, am I allowed to say that here?
) or aura or chakras. I'm still sceptical.
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it is AC->Convert to DC->convert to AC->AC
battery is connected in paralel to the dc and back to AC regeneration
battery gets charged when not used a from the DC convertor
And
battery gives differential power to the AC convertor when needed.
Only time battery is used fully is when there is no input power
some info Here
battery is connected in paralel to the dc and back to AC regeneration
battery gets charged when not used a from the DC convertor
And
battery gives differential power to the AC convertor when needed.
Only time battery is used fully is when there is no input power
some info Here
ajay124
Well-Known Member
Spoke to Elecon for a Bhurji CVT.
Power outputs available are 1220,1900,2400 kva.
As Hifiashok had pointed out a CVT works best a peak load.Less hum too.
My Power Amp needs 900 va.Will be confirming consumption of Arcam cdp
and Bryston BP6 Pre.Anybody with knowledge of this?
Maybe I can opt for the 1220 va CVT.Cheaper and would work at close to peak load.
Correction
A little confusion about the power output.
Have received tech specs by mail.
Attaching with the next post.
Power outputs available are 1220,1900,2400 kva.
As Hifiashok had pointed out a CVT works best a peak load.Less hum too.
My Power Amp needs 900 va.Will be confirming consumption of Arcam cdp
and Bryston BP6 Pre.Anybody with knowledge of this?
Maybe I can opt for the 1220 va CVT.Cheaper and would work at close to peak load.
Correction
A little confusion about the power output.
Have received tech specs by mail.
Attaching with the next post.
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I'd be obliged if you guys explain this differential thing a little more elaborately.
I am not the expert here. My understanding is that if the output needs to be rated at 1 KVA but the input from the AC source is only 950VA, the additional 50 VA will be taken from the battery
ajay124
Well-Known Member
Attaching Specs of Bhurji CVT's.
Trying to decide between these two models:
BAVR 1920 CG
BAVR 2400 CG
Any suggestions based on the specs?
Power consumption may go up a little
if I upgrade to an Esoteric or Accuphase cdp
but I don't plan to add anything else.
ImageShack® - Online Photo and Video Hosting
Trying to decide between these two models:
BAVR 1920 CG
BAVR 2400 CG
Any suggestions based on the specs?
Power consumption may go up a little
if I upgrade to an Esoteric or Accuphase cdp
but I don't plan to add anything else.
ImageShack® - Online Photo and Video Hosting
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ajay124
Well-Known Member
I have not been able to confirm exact power consumption for the Bryston 4B SST+BP6+Arcam CD 192.
According to the specs for the two Bhurji cvt models I have mentioned above,
output power at unity power factor for a standard input range 180-275 V
is 1600W and 2000W respectively.
I would appreciate if somebody could take some time out to glance at the specs of the 4B SST,BP6 and Arcam CD 192 at the Bryston and Arcam websites and then suggest a model.
Price difference is not much
1600W for 23K
2000W for 25K.
hifiashok
Well-Known Member
hifiashok said:
arj said:
captrajesh said:
Thad said:
i will re-iterate. in the case of an on-line UPS, only differential power is drawn from the batteries in case of a shortfall at the input. this is one of the two critical reasons why the input AC is converted to DC and then again converted to AC, DC being uni-directional. consequently, on the switch-over time delay, there is practically none since, immediately against the power at the input being lost, the differential to zero AC i/p would be drawn from the batteries.
the suggestion that there is a commercially viable option in UPSs where 100% o/p power is generated from the batteries and the i/p power is only used to charge the batteries is impractical. typical batteries (LA and/or SMF) have a max./realistic charge cycle of 1100. consequently, if 100% power was needed to be provided only from the batteries, imagine the practical life of the batteries!! however, having stated this, it is not as if this is not a possibility and this implementation MAY be needed in some cases (like the indian railways where (almost) everything runs on DC), but definitely not in the case of regular AC equipment.
no isolation tfr at the o/p of the o/l UPS, no isolation, period.
btw, there is a suggestion, tho' also impractical. if one is so paranoid of the input surge, etc., and one after all STILL wants to go the o/l UPS way, one may buy the o/l UPS rated with say 2 hr. battery backup (assuming this is the longest possible time for a listening session to extend; if not, an even larger battery bank for the backup!) and then, just prior to start of the session, turn off the mains i/p to the UPS. Lo, 100% o/p from the batteries!!! however, you would still need to grapple with the harmonics introduced into the o/p line by the IGBT (rectifier/hi-freq switcher to convert DC to AC) that would pollute the audio, the original reason why i suggested a CVT over a UPS.
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There are different type of topologies used in online ups designs, explaining everything is beyond the scope of this , so i will try to give one oversimplified example
In a conventional rectifier /float charger(Ac-DC) - inverter(DC to AC) design, the mains is given to a rectifier cum charger which is ORed or parallel with the battery and the inverter which drives the load is connected to the parallel dc source of battery and rectifier , (remember that there is no switching between battery and mains like offline or lineinteractive ups's) during the normal operating conditions the rectifier output voltage is kept slightly higher than the battery voltage so that the inverter takes the energy to run the load from the rectifier and not from battery , Now because the ac rectifier and battery are parralel whenever the input drops due to any reason(load increase, input V less etc. the battery supplies the energy to drive the load
Battery is kept floating by the ac rectifier, to use the it as a backup source and not the primary source
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hifiashok
Well-Known Member
there are contradictions on this link; 'Aside from the cost, a disadvantage of the online UPS is its inefficiency. All the power going to the loads is converted from AC to DC and back to AC, which means much of the power is dissipated as heat. Furthermore, this is happening all the time, not just during a power failure, and while running equipment that draws a lot of power'. if the batteries are being used to generate the o/p AC, then where does the AC -> DC -> AC come in?
shershah
New Member
it is so clear that CVT is the one!
thanks! - to all forum members
thanks! - to all forum members
it is so clear that CVT is the one!
thanks! - to all forum members
that is the crystal clear, diamond bullet clarity that i so appreciate.
ajay124
Well-Known Member
@Moktan
A diamond bullet clarity
The natural state of mankind and womankind since the beginning of creation has been one of confusion and incomprehension.
We have yet to attain the knowledge which Socrates had two thousand years,
"All that I know is that I know nothing".
An acknowledgement of ignorance by the preacher's and preached alike,would be the first step on the road to enlightenment.
Alas we are all too full of our 'borrowed opinions and convictions'!Google has made it even simpler for the fool to appear to be wise.
"The cradle rocks above an abyss,and common sense tells us that our existence is but a brief crack of light between eternities of darkness." Nabokov.
Sorry for going off tangent.High on the mists of Islay and Mozart,I'm taking a momentary break from power conditioning
A diamond bullet clarity
The natural state of mankind and womankind since the beginning of creation has been one of confusion and incomprehension.
We have yet to attain the knowledge which Socrates had two thousand years,
"All that I know is that I know nothing".
An acknowledgement of ignorance by the preacher's and preached alike,would be the first step on the road to enlightenment.
Alas we are all too full of our 'borrowed opinions and convictions'!Google has made it even simpler for the fool to appear to be wise.
"The cradle rocks above an abyss,and common sense tells us that our existence is but a brief crack of light between eternities of darkness." Nabokov.
Sorry for going off tangent.High on the mists of Islay and Mozart,I'm taking a momentary break from power conditioning
shershah
New Member
all else, is pretence :sad:
ajay124
Well-Known Member
Manufacturer's and literature of CVT's recommend that they should be run close to their maximum load and in no case should the load fall to less than 50%.
I am fairly convinced that a CVT is the way to go as it addresses most issues except providing a back up.It is also relatively maintenance free and does not have recurring expenses.
What I need to establish is the power consumption of my system and the optimum CVT running at 70-75% load for that consumptiom.
If a cdp and pre consumes roughly 50W each,I would like to confirm what the 4B SST rated at 300W at 8 ohms and 500W at 4 ohms feasts on.The tech specs of my Vienna Acoustic speaker's recommend an amp with power rating of between 40W-250W presumably at 4 ohms.Given these specs would the 4B SST ever be operating anywhere near it's peak power consumption?
I am bad at all this stuff and would appreciate a little light on what may appear to be very naive questions
I am fairly convinced that a CVT is the way to go as it addresses most issues except providing a back up.It is also relatively maintenance free and does not have recurring expenses.
What I need to establish is the power consumption of my system and the optimum CVT running at 70-75% load for that consumptiom.
If a cdp and pre consumes roughly 50W each,I would like to confirm what the 4B SST rated at 300W at 8 ohms and 500W at 4 ohms feasts on.The tech specs of my Vienna Acoustic speaker's recommend an amp with power rating of between 40W-250W presumably at 4 ohms.Given these specs would the 4B SST ever be operating anywhere near it's peak power consumption?
I am bad at all this stuff and would appreciate a little light on what may appear to be very naive questions
From bryston website, the power consumption in bold for different modes, please crosscheck if i selected the correct mode
http://www.bryston.com/BrystonSite05/BrystonDocs.html#sstamp
Power Consumption
& Heat Load At Idle 170 Watts
Max. Heat Dissipation 580 Btu/Hr.
2 channels @ 300W @ 8 ohms 1280 Watts Max. Heat Dissipation 8 ohms 2320 Btu/Hr.
2 channels @ 500W @ 4 ohms 2100W Max. Heat Dissipation 4 ohms 3750 Btu/Hr
Bridged @ 900W @ 8 ohms 2040W
Max. Heat Dissipation 8 ohms 3890 Btu/Hr
http://www.bryston.com/BrystonSite05/BrystonDocs.html#sstamp
Power Consumption
& Heat Load At Idle 170 Watts
Max. Heat Dissipation 580 Btu/Hr.
2 channels @ 300W @ 8 ohms 1280 Watts Max. Heat Dissipation 8 ohms 2320 Btu/Hr.
2 channels @ 500W @ 4 ohms 2100W Max. Heat Dissipation 4 ohms 3750 Btu/Hr
Bridged @ 900W @ 8 ohms 2040W
Max. Heat Dissipation 8 ohms 3890 Btu/Hr
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