sine wave UPS with internal battery

[sanjgupt]

The output voltage from ordinary computer ups (known as offline or line interactive ups) is usually square wave. You can use this type of ups to power your lcd tv, bd player, amplifiers etc. For your use (2-3 min) it is sufficient. Ordinary desktop ups will give around 10 -15 minutes of backup time. Usually their load handling power is 600 va which is approximately 360W. So the total power consumption of all the devices connected to such a ups should not exceed 360W. A 1000 va ups has a capacity of around 600W.

Hi Borg
one thing is not yet clarified yet. what is the computer UPS output when mains is present. does it directly connects to mains when power is present.
is it always square wave or only when power fails and inverter operation comes into effect.

Thanks

 

[baijuxavior]

Hi Borg
one thing is not yet clarified yet. what is the computer UPS output when mains is present. does it directly connects to mains when power is present.
is it always square wave or only when power fails and inverter operation comes into effect.

Thanks

For offline ups when mains is present it will simply output the mains voltage.So the output will be sine wave. Yes only on power failures and voltage fluctuations the inverter action of the offline ups will come into effect and then the output will be square wave unless you use a sine wave ups. On the other hand online ups will always supply the output from the battery irrespective of the mains power status and you will get constant voltage.

 

[borg]

Hi Borg
one thing is not yet clarified yet. what is the computer UPS output when mains is present. does it directly connects to mains when power is present.
is it always square wave or only when power fails and inverter operation comes into effect.

Thanks

i thought it was clear in last post, yes sq wave only when in inverter( powerfailed/too low/high power)



in line interactive(like sua1000i) or offline ups when mains is present within the specified input range(say 160-280v) it is connected to output. although the output voltage will be regulated within a range(say 200-240v) , when input mains fails OR goes more or less than the spec'd input range the inverter will drive the output load and mains is disconnected till it comes back

so it is not completely isolated from mains ALL the time

these topics are discussed in detail in other threads like this one

 

[ShakenSoul]

Guys, I need a UPS for my AV stuff only for shutdown purpose when the main power fails. I don't plan to run the HT on UPS, I only need the time to turn the system off safely.

HT is 42" Pana LCD, HTPC, Onkyo 508, Jamo S606 FS speakers with Sub 300.

I don't want to spend a lot on the UPS, budget is around 5k.

Will the Microtek 1000VA Twin Guard UPS suffice for this purpose ?

Line Interactive UPS

Or is there something else I should get ?

 

[captrajesh]

With sinewave the system will not know if it is on mains or inverter and apart from cost ( which is ok in my case as it is protecting equipments 20 times worth) there is no disadvantages, that is why i chose sinewave over the other

Hi Borg,

In the thread that you have referred, it was deduced that an online UPS cannot provide adequate power to meet the dynamic demand during music reproduction (i.e. instantaneously cater to the power requirements while playing transients and peaks) and thus does not do justice to music fully. Hence, knowledgeable forum members have concluded that raw power is the best for music, provided it is clean. Didn't you consider that to be a disadvantage?

BTW, do you think having a bank of capacitors in the circuit to cater to such transients would help?

I'd appreciate if you could comment.

Regards


Rajesh

 

[borg]

My above comment is about protection/quality of ups waveform. not from an audiophile point of view

"it was deduced that an online UPS cannot provide adequate power to meet the dynamic demand during music reproduction "

This is not my opinion, i am not qualified/ dont have a setup to comment on this.Mine is not an online but a line interactive sinewave ups and i never felt any such problems

You can check with ajay124 as he is using an online ups and seems quite happy with that

With an online ups , if you are worried about supplying the transients get the one with highest crest factor and also if budget allows get a bigger size'd one

if you increase the capcitance in the dc filter of amp power supply , that will surely help

 

[baijuxavior]

Guys, I need a UPS for my AV stuff only for shutdown purpose when the main power fails. I don't plan to run the HT on UPS, I only need the time to turn the system off safely.

HT is 42" Pana LCD, HTPC, Onkyo 508, Jamo S606 FS speakers with Sub 300.

I don't want to spend a lot on the UPS, budget is around 5k.

Will the Microtek 1000VA Twin Guard UPS suffice for this purpose ?

Line Interactive UPS

Or is there something else I should get ?

A 1000va ups can handle approximately 600w of load. So sum up the total wattage of all your mentioned devices. If it is below 600w, you can go for that ups.