Inverters

Discussion in 'NZ Computing' started by Matty F, Feb 7, 2009.

  1. Matty F

    Matty F Guest

    Is the output from a cheap inverter able to run my computer, Sky, TV,
    amplifier and fridge/freezer? It won't be a very good sine wave. It
    says "Continuous output power: 1000W, Peak output power: 1500W".
    Matty F, Feb 7, 2009
    #1
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  2. Matty F

    Peter M Guest

    On Sun, 08 Feb 2009 00:38:29 +1300, Richard <> wrote:

    >Matty F wrote:
    >> On Feb 7, 6:54 pm, whoisthis <> wrote:
    >>> In article
    >>> <>,
    >>> Matty F <> wrote:
    >>>
    >>>> Is the output from a cheap inverter able to run my computer, Sky, TV,
    >>>> amplifier and fridge/freezer? It won't be a very good sine wave. It
    >>>> says "Continuous output power: 1000W, Peak output power: 1500W".
    >>> start up current of your fridge/freezer will be an issue, quite apart
    >>> from the fact that the harmonics in the shitty sine wave it uses will
    >>> cause excessive wear in the compressor.

    >>
    >> The fridge uses about 110 watts. Surely a 1500 watt maximum should
    >> handle that?

    >
    >They really should call them 1000 VA - since a motor is quite inductive
    >then it will use more then 110 VA when running, and a lot more when
    >starting.




    He was refering to Watts not VA, Watts is Watts, that is the TRUE load..

    >Most modified sinewave inverters are pretty good about massive peak
    >outputs since they have 320v sitting there in some capacitors which they
    >are just turning on and off to the load, older ones that inverted at low
    >voltage and then stepped up are the ones with the issues on high startup
    >loads.
    Peter M, Feb 7, 2009
    #2
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  3. Matty F

    Richard Guest

    Peter M wrote:
    > On Sun, 08 Feb 2009 00:38:29 +1300, Richard <> wrote:
    >
    >> Matty F wrote:
    >>> On Feb 7, 6:54 pm, whoisthis <> wrote:
    >>>> In article
    >>>> <>,
    >>>> Matty F <> wrote:
    >>>>
    >>>>> Is the output from a cheap inverter able to run my computer, Sky, TV,
    >>>>> amplifier and fridge/freezer? It won't be a very good sine wave. It
    >>>>> says "Continuous output power: 1000W, Peak output power: 1500W".
    >>>> start up current of your fridge/freezer will be an issue, quite apart
    >>>> from the fact that the harmonics in the shitty sine wave it uses will
    >>>> cause excessive wear in the compressor.
    >>> The fridge uses about 110 watts. Surely a 1500 watt maximum should
    >>> handle that?

    >> They really should call them 1000 VA - since a motor is quite inductive
    >> then it will use more then 110 VA when running, and a lot more when
    >> starting.

    >
    >
    >
    > He was refering to Watts not VA, Watts is Watts, that is the TRUE load..


    No, he called the inverter 1000W, which they are not. Inverters have to
    supply all of the VA demanded of them, unlike generators which are
    pretty effecient even into really bad power factors.

    The fridge may be 110W, but we have no idea of its power factor - if
    what the old fridge here did is any indication it will go all over the
    place, the cheap elto power meter will only measure down to 33% - which
    I often saw it give - over an amp consumed but only 90-100 watts consumed.
    Richard, Feb 7, 2009
    #3
  4. Matty F

    Guest

    On Feb 7, 4:52 pm, Matty F <> wrote:
    > Is the output from a cheap inverter able to run my computer, Sky, TV,
    > amplifier and fridge/freezer? It won't be a very good sine wave. It
    > says "Continuous output power: 1000W,  Peak output power: 1500W".


    The fridge / freezer will be the bad one....and possibly the amp if
    you turn it on and its at a high volume....if the fridge freezer is an
    absorption type and not the compressor type than it maybe fine.

    I just got a 300watt one to run my laptop in my 4wd....at $120 it
    looks cheaper to get 3 of these and do each unit by itself than get a
    1000w one.....just an idea.....
    , Feb 10, 2009
    #4
  5. Matty F

    Guest

    On Feb 7, 7:27 pm, Matty F <> wrote:
    > On Feb 7, 6:54 pm, whoisthis <> wrote:
    >
    > > In article
    > > <>,
    > >  Matty F <> wrote:

    >
    > > > Is the output from a cheap inverter able to run my computer, Sky, TV,
    > > > amplifier and fridge/freezer? It won't be a very good sine wave. It
    > > > says "Continuous output power: 1000W,  Peak output power: 1500W".

    >
    > > start up current of your fridge/freezer will be an issue, quite apart
    > > from the fact that the harmonics in the shitty sine wave it uses will
    > > cause excessive wear in the compressor.

    >
    > The fridge uses about 110 watts. Surely a 1500 watt maximum should
    > handle that?


    thats continious and not start up....the startup without an un-loader
    could be 10~15 times the continious running load....

    regards

    thing
    , Feb 10, 2009
    #5
  6. Matty F

    Matty F Guest

    On Feb 10, 3:10 pm, wrote:
    > On Feb 7, 4:52 pm, Matty F <> wrote:
    >
    > > Is the output from a cheap inverter able to run my computer, Sky, TV,
    > > amplifier and fridge/freezer? It won't be a very good sine wave. It
    > > says "Continuous output power: 1000W, Peak output power: 1500W".

    >
    > The fridge / freezer will be the bad one....and possibly the amp if
    > you turn it on and its at a high volume....if the fridge freezer is an
    > absorption type and not the compressor type than it maybe fine.
    >
    > I just got a 300watt one to run my laptop in my 4wd....at $120 it
    > looks cheaper to get 3 of these and do each unit by itself than get a
    > 1000w one.....just an idea.....


    I've changed my mind. I think I will get a generator instead. Now I
    need to know what size generator will run my 110 watt fridge plus a
    few hundred watts of computer/TV etc.
    Matty F, Feb 10, 2009
    #6
  7. Matty F

    Gib Bogle Guest

    wrote:
    > On Feb 7, 4:52 pm, Matty F <> wrote:
    >> Is the output from a cheap inverter able to run my computer, Sky, TV,
    >> amplifier and fridge/freezer? It won't be a very good sine wave. It
    >> says "Continuous output power: 1000W, Peak output power: 1500W".

    >
    > The fridge / freezer will be the bad one....and possibly the amp if
    > you turn it on and its at a high volume....if the fridge freezer is an
    > absorption type and not the compressor type than it maybe fine.
    >
    > I just got a 300watt one to run my laptop in my 4wd....at $120 it
    > looks cheaper to get 3 of these and do each unit by itself than get a
    > 1000w one.....just an idea.....


    How does the power supply in the computer feel about the square wave
    coming from the inverter?
    Gib Bogle, Feb 10, 2009
    #7
  8. Matty F

    Dave Doe Guest

    In article <gmquvm$m6i$>,
    says...
    > wrote:
    > > On Feb 7, 4:52 pm, Matty F <> wrote:
    > >> Is the output from a cheap inverter able to run my computer, Sky, TV,
    > >> amplifier and fridge/freezer? It won't be a very good sine wave. It
    > >> says "Continuous output power: 1000W, Peak output power: 1500W".

    > >
    > > The fridge / freezer will be the bad one....and possibly the amp if
    > > you turn it on and its at a high volume....if the fridge freezer is an
    > > absorption type and not the compressor type than it maybe fine.
    > >
    > > I just got a 300watt one to run my laptop in my 4wd....at $120 it
    > > looks cheaper to get 3 of these and do each unit by itself than get a
    > > 1000w one.....just an idea.....

    >
    > How does the power supply in the computer feel about the square wave
    > coming from the inverter?


    Being a switch mode power supply, I wouldn't imagine any problems.

    --
    Duncan
    Dave Doe, Feb 10, 2009
    #8
  9. Matty F

    Richard Guest

    Gib Bogle wrote:
    > wrote:
    >> On Feb 7, 4:52 pm, Matty F <> wrote:
    >>> Is the output from a cheap inverter able to run my computer, Sky, TV,
    >>> amplifier and fridge/freezer? It won't be a very good sine wave. It
    >>> says "Continuous output power: 1000W, Peak output power: 1500W".

    >>
    >> The fridge / freezer will be the bad one....and possibly the amp if
    >> you turn it on and its at a high volume....if the fridge freezer is an
    >> absorption type and not the compressor type than it maybe fine.
    >>
    >> I just got a 300watt one to run my laptop in my 4wd....at $120 it
    >> looks cheaper to get 3 of these and do each unit by itself than get a
    >> 1000w one.....just an idea.....

    >
    > How does the power supply in the computer feel about the square wave
    > coming from the inverter?


    They dont seem to care, and considering the first thing they do is
    rectify to DC, I wouldnt expect them to.
    Richard, Feb 10, 2009
    #9
  10. Matty F

    Guest

    On Feb 9, 11:15 pm, Gib Bogle <> wrote:
    > How does thepower supplyin the computer feel about the square wave
    > coming from the inverter?


    Computers are some of the most robust appliances. Those square
    waves can be destructive to motorized appliances such as the
    compressor. It is called a computer grade UPS because it is only
    intended for more robust appliances such as computers. To many, these
    technical facts will dispute popular myths.

    Generators create a difference problem. For example, if the
    compressor turned off, the generator may spike up a voltage that is
    harmful to other appliances. The best protection for appliances
    starts by eliminating cost controls. Numerous electrical reasons why
    generators (such as designed by Honda) are much less expensive -
    despite the retail store price. The prices says little about the
    actual cost.
    , Feb 11, 2009
    #10
  11. Matty F

    Richard Guest

    wrote:
    > On Feb 9, 11:15 pm, Gib Bogle <> wrote:
    >> How does thepower supplyin the computer feel about the square wave
    >> coming from the inverter?

    >
    > Computers are some of the most robust appliances. Those square
    > waves can be destructive to motorized appliances such as the
    > compressor. It is called a computer grade UPS because it is only
    > intended for more robust appliances such as computers. To many, these
    > technical facts will dispute popular myths.
    >
    > Generators create a difference problem. For example, if the
    > compressor turned off, the generator may spike up a voltage that is
    > harmful to other appliances. The best protection for appliances
    > starts by eliminating cost controls. Numerous electrical reasons why
    > generators (such as designed by Honda) are much less expensive -
    > despite the retail store price. The prices says little about the
    > actual cost.


    Interestingly enough I have had a couple of inverters that have had the
    second stage die - was still making the high voltage just not switching
    it into ac - disconnecting it and running the + and - 170 odd volts to
    the AC outlet has run everything electronig I have tried on it.
    Richard, Feb 12, 2009
    #11
  12. Matty F

    Peter M Guest

    On Wed, 11 Feb 2009 15:44:58 -0800 (PST), wrote:

    >On Feb 9, 11:15 pm, Gib Bogle <> wrote:
    >> How does thepower supplyin the computer feel about the square wave
    >> coming from the inverter?

    >
    > Computers are some of the most robust appliances. Those square
    >waves can be destructive to motorized appliances such as the
    >compressor. It is called a computer grade UPS because it is only
    >intended for more robust appliances such as computers. To many, these
    >technical facts will dispute popular myths.
    >
    > Generators create a difference problem. For example, if the
    >compressor turned off, the generator may spike up a voltage that is
    >harmful to other appliances. The best protection for appliances
    >starts by eliminating cost controls. Numerous electrical reasons why
    >generators (such as designed by Honda) are much less expensive -
    >despite the retail store price. The prices says little about the
    >actual cost.




    Please post these FACTS not your drivel
    Peter M, Feb 12, 2009
    #12
  13. Matty F

    Richard Guest

    Peter M wrote:

    >> Generators create a difference problem. For example, if the
    >> compressor turned off, the generator may spike up a voltage that is
    >> harmful to other appliances. The best protection for appliances
    >> starts by eliminating cost controls. Numerous electrical reasons why
    >> generators (such as designed by Honda) are much less expensive -
    >> despite the retail store price. The prices says little about the
    >> actual cost.

    >
    >
    >
    > Please post these FACTS not your drivel


    Do you know anything about how voltage regulation on a generator works?
    Heard of loaddumping causing a spike? most common in cars when
    disconnecting a large load, but happens on AC generators as well.
    Richard, Feb 12, 2009
    #13
  14. Matty F

    Guest

    On Feb 11, 11:32 pm, Peter M <> wrote:
    > Please post these FACTS  not your drivel


    Richard has posted facts that anyone with basic electrical knowledge
    would know. Richard provided the problem's name which is why
    solutions starts with purchasing the better generator (ie Honda).

    Obviously if square waves were a problem, then discussions about
    wattage were quite irrelevant. Peter M also did not understand the
    significance of volt-amps. This explains why his latest post uses
    profanity and insult.

    OP should appreciate a problem called load dump which is why better
    generators actually end up costing less. Those generators also have
    other advantages. A small generator (1000 watts) should be more than
    sufficient for the loads described.
    , Feb 13, 2009
    #14
  15. Matty F

    Peter M Guest

    On Thu, 12 Feb 2009 17:33:23 -0800 (PST), wrote:

    >On Feb 11, 11:32 pm, Peter M <> wrote:
    >> Please post these FACTS  not your drivel

    >
    > Richard has posted facts that anyone with basic electrical knowledge
    >would know. Richard provided the problem's name which is why
    >solutions starts with purchasing the better generator (ie Honda).
    >
    > Obviously if square waves were a problem, then discussions about
    >wattage were quite irrelevant. Peter M also did not understand the
    >significance of volt-amps. This explains why his latest post uses
    >profanity and insult.




    No it does not, go read it again and I do know a lot about Amps, Watts and TRUE RMS, as
    I have been it the trade for some 40 years and have past the NZ electrical registration
    test.


    > OP should appreciate a problem called load dump which is why better
    >generators actually end up costing less. Those generators also have
    >other advantages. A small generator (1000 watts) should be more than
    >sufficient for the loads described.



    The Header States Inverters not Generator at all.

    To me you are the one posting the Insults, you know nothing about my background and what I
    have done and achieved..
    Peter M, Feb 13, 2009
    #15
  16. Matty F

    Peter M Guest

    On Wed, 11 Feb 2009 05:05:40 +1300, Richard <> wrote:

    >Gib Bogle wrote:
    >> wrote:
    >>> On Feb 7, 4:52 pm, Matty F <> wrote:
    >>>> Is the output from a cheap inverter able to run my computer, Sky, TV,
    >>>> amplifier and fridge/freezer? It won't be a very good sine wave. It
    >>>> says "Continuous output power: 1000W, Peak output power: 1500W".
    >>>
    >>> The fridge / freezer will be the bad one....and possibly the amp if
    >>> you turn it on and its at a high volume....if the fridge freezer is an
    >>> absorption type and not the compressor type than it maybe fine.
    >>>
    >>> I just got a 300watt one to run my laptop in my 4wd....at $120 it
    >>> looks cheaper to get 3 of these and do each unit by itself than get a
    >>> 1000w one.....just an idea.....

    >>
    >> How does the power supply in the computer feel about the square wave
    >> coming from the inverter?

    >
    >They dont seem to care, and considering the first thing they do is
    >rectify to DC, I wouldnt expect them to.



    It does due to the repetitive high peak currents that are not evident in a sinewave
    supply, but can be at start up tims unless the unite has a soft start..
    Peter M, Feb 13, 2009
    #16
  17. Matty F

    Richard Guest

    Peter M wrote:

    >> They dont seem to care, and considering the first thing they do is
    >> rectify to DC, I wouldnt expect them to.

    >
    >
    > It does due to the repetitive high peak currents that are not evident in a sinewave
    > supply, but can be at start up tims unless the unite has a soft start..


    Ok, then I guess that all the PCs I have had over the years on a non
    sinewave UPS should have exploded as soon as inverter kicked in?

    There are inductors etc inline with the input that will limit the inrush
    etc, so I still dont see that there would be a problem with inrush on a
    modified squarewave inverter.
    Richard, Feb 13, 2009
    #17
  18. Matty F

    Dave Doe Guest

    In article <>,
    says...
    > On Wed, 11 Feb 2009 05:05:40 +1300, Richard <> wrote:
    >
    > >Gib Bogle wrote:
    > >> wrote:
    > >>> On Feb 7, 4:52 pm, Matty F <> wrote:
    > >>>> Is the output from a cheap inverter able to run my computer, Sky, TV,
    > >>>> amplifier and fridge/freezer? It won't be a very good sine wave. It
    > >>>> says "Continuous output power: 1000W, Peak output power: 1500W".
    > >>>
    > >>> The fridge / freezer will be the bad one....and possibly the amp if
    > >>> you turn it on and its at a high volume....if the fridge freezer is an
    > >>> absorption type and not the compressor type than it maybe fine.
    > >>>
    > >>> I just got a 300watt one to run my laptop in my 4wd....at $120 it
    > >>> looks cheaper to get 3 of these and do each unit by itself than get a
    > >>> 1000w one.....just an idea.....
    > >>
    > >> How does the power supply in the computer feel about the square wave
    > >> coming from the inverter?

    > >
    > >They dont seem to care, and considering the first thing they do is
    > >rectify to DC, I wouldnt expect them to.

    >
    >
    > It does due to the repetitive high peak currents that are not evident in a sinewave
    > supply, but can be at start up tims unless the unite has a soft start..


    It does not. The worst result is spiking back on the AC line - but as
    it's an inverter driving the AC, that doesn't happen on the battery.
    i.e. lots and lots of switch mode power supplies (qv computer PSU's) can
    cause problems on the local AC circuit. But that's not the question -
    as there is *no* AC circuit, but an inverter.

    Switch mode power supplies (computer PSU's) will quite happily swallow
    square AC waves.

    --
    Duncan
    Dave Doe, Feb 13, 2009
    #18
  19. Matty F

    Peter M Guest

    On Fri, 13 Feb 2009 17:19:34 +1300, Bret <> wrote:

    >On Fri, 13 Feb 2009 15:20:59 +1300, Peter M wrote:
    >
    >> On Wed, 11 Feb 2009 05:05:40 +1300, Richard <> wrote:
    >>
    >>>Gib Bogle wrote:
    >>>> wrote:
    >>>>> On Feb 7, 4:52 pm, Matty F <> wrote:
    >>>>>> Is the output from a cheap inverter able to run my computer, Sky, TV,
    >>>>>> amplifier and fridge/freezer? It won't be a very good sine wave. It
    >>>>>> says "Continuous output power: 1000W, Peak output power: 1500W".
    >>>>>
    >>>>> The fridge / freezer will be the bad one....and possibly the amp if
    >>>>> you turn it on and its at a high volume....if the fridge freezer is an
    >>>>> absorption type and not the compressor type than it maybe fine.
    >>>>>
    >>>>> I just got a 300watt one to run my laptop in my 4wd....at $120 it
    >>>>> looks cheaper to get 3 of these and do each unit by itself than get a
    >>>>> 1000w one.....just an idea.....
    >>>>
    >>>> How does the power supply in the computer feel about the square wave
    >>>> coming from the inverter?
    >>>
    >>>They dont seem to care, and considering the first thing they do is
    >>>rectify to DC, I wouldnt expect them to.

    >>
    >>
    >> It does due to the repetitive high peak currents that are not evident in a sinewave
    >> supply, but can be at start up tims unless the unite has a soft start..

    >
    >Hey Roger, can you get the person who was typing your posts back as you are
    >becoming undecipherable again.




    Yes Adolf I will get the Queen to do it next time as I do have contacts in the Royal
    Family..
    Peter M, Feb 13, 2009
    #19
  20. Matty F

    ~misfit~ Guest

    Somewhere on teh intarwebs Bret wrote:
    > On Fri, 13 Feb 2009 17:32:04 +1300, Peter M wrote:
    >
    >> On Fri, 13 Feb 2009 17:19:34 +1300, Bret <> wrote:
    >>
    >>> On Fri, 13 Feb 2009 15:20:59 +1300, Peter M wrote:
    >>>
    >>>> On Wed, 11 Feb 2009 05:05:40 +1300, Richard <>
    >>>> wrote:
    >>>>
    >>>>> Gib Bogle wrote:
    >>>>>> wrote:
    >>>>>>> On Feb 7, 4:52 pm, Matty F <> wrote:
    >>>>>>>> Is the output from a cheap inverter able to run my computer,
    >>>>>>>> Sky, TV, amplifier and fridge/freezer? It won't be a very good
    >>>>>>>> sine wave. It says "Continuous output power: 1000W, Peak
    >>>>>>>> output power: 1500W".
    >>>>>>>
    >>>>>>> The fridge / freezer will be the bad one....and possibly the
    >>>>>>> amp if you turn it on and its at a high volume....if the fridge
    >>>>>>> freezer is an absorption type and not the compressor type than
    >>>>>>> it maybe fine.
    >>>>>>>
    >>>>>>> I just got a 300watt one to run my laptop in my 4wd....at $120
    >>>>>>> it looks cheaper to get 3 of these and do each unit by itself
    >>>>>>> than get a 1000w one.....just an idea.....
    >>>>>>
    >>>>>> How does the power supply in the computer feel about the square
    >>>>>> wave coming from the inverter?
    >>>>>
    >>>>> They dont seem to care, and considering the first thing they do is
    >>>>> rectify to DC, I wouldnt expect them to.
    >>>>
    >>>>
    >>>> It does due to the repetitive high peak currents that are not
    >>>> evident in a sinewave supply, but can be at start up tims unless
    >>>> the unite has a soft start..
    >>>
    >>> Hey Roger, can you get the person who was typing your posts back as
    >>> you are becoming undecipherable again.

    >>
    >> Yes Adolf I will get the Queen to do it next time as I do have
    >> contacts in the Royal Family..

    >
    > Can I invoke Godwin here?


    Hardly necessary with Roger methinks....
    --
    Shaun.

    "Build a man a fire, and he`ll be warm for a day. Set a man on fire, and
    he`ll be warm for the rest of his life." Terry Pratchett, Jingo.
    ~misfit~, Feb 13, 2009
    #20
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