Voltage transformation

Discussion in 'General Electronics Chat' started by 666shan666, Jun 13, 2011.

  1. 666shan666

    Thread Starter New Member

    Jun 13, 2011
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    0
    Hi,
    I need some assistance regarding step-up transformers.
    I used to live in Chandigarh, India & the voltage here varies from 220v-230v. But recently I move to the outskirts of the city & now where I live has a lot of voltage issues. Due to this one of my computer UPS got burnt, literally. I need to power up my 1200 watt computer for which I am using an APC BR1500-IN with extra battery. The problem is that the voltage never stays at 230v. Rather, it rarely reaches 230v. It some times fluctuates between 212-216 volts, but more often than not, stays at 188v-194v. Frequently, goes below 180v to to 164v, 150v & even 130v. The APC power chute software helps me get these values. I was using a stabilizer & a surge protector, they cant fix a voltage this low. Due to this, the UPS does not charge properly. I charges when it receives 204v or above. when the voltage goes below 180v, the UPS switches to battery power. I need to convert this low voltage to 220v or 230v stable to ensure no loss of property. I was looking at a 2000watt step up transformer imported from US- http://orders.ebay.in/ws/eBayISAPI.d...d=270693746189.
    What I want to know is, if this transformer requires 110v-127v input, what effect will it have if it gets 188v or more?
    If that is fatal to the transformer, can I connect two of them in series? One will connect to 188v input to 110v output, & this output will connect to 110v input of second transformer to 220v output. Will this combination, or for that matter, anything work for me? Or is it just a wild goose chase?
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    The link you posted does not work.

    You need to get a voltage stabilizer designed to operate on the power where you are. Don't try to import one designed to work in the USA, because we have 120v 60Hz here, where you have 220v 50Hz.

    Just get the proper device for your requirements. Or, move to a location where the power is better.
     
  3. 666shan666

    Thread Starter New Member

    Jun 13, 2011
    2
    0
    Try This

    I was given the understanding that this was universal. Also If it is not, & I get the one that is, will the setup I mentioned work?
    & moving is not an option, I just bought this house..
     
    Last edited: Jun 13, 2011
  4. SgtWookie

    Expert

    Jul 17, 2007
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    No, that will not work for what you want it to do.

    It's designed to operate 220v/240v appliances on 110v/120v mains, or 110v/120v on 220v/240v mains.
     
  5. BillB3857

    Senior Member

    Feb 28, 2009
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  6. someonesdad

    Senior Member

    Jul 7, 2009
    1,585
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    I was going to suggest a ferroresonant transformer; I have an old Raytheon one I bought for testing line-powered UV fluorescent tubes and it works great. But BillB3857 beat me to it...
     
  7. awright

    Well-Known Member

    Jul 5, 2006
    84
    7
    One characteristic of ferroresonant transformers to bear in mind is that they are frequency dependent. The "Operating Characteristics" section of the cited device states that output voltage varies 1.5% for each 1% change in input frequency. If 666shan666's voltage is as badly regulated as he states, it is possible that his input frequency is also very poorly regulated. Not necessarily a deal breaker, but something to check out before investing in a ferroresonant transformer. Of course, the ferroresonant transformer would have to be specified for 50 Hz service.

    Additionally, I doubt that the ferroresonant technology can correct for the extremes of voltage variation that 666shan666 mentions. The Operating Characteristics mention holding output voltage within specs for inputs down to 65% of rated. That would be about 150 volts for 230 volt rated output

    A lab that I worked in as a student back in '62 or so had a General Radio electromechanical line voltage regulator that consisted of a servo-motor driven Variac feeding a buck-boost transformer that corrected line voltage. The servo sensed the output voltage and drove the Variac to maintain rated output. Completely frequency independent and no distortion of the line voltage. Kind of mechanically noisy 'though.

    Clearly, a device of this type could be designed to operate over any arbitrary input voltage range by appropriate selection of Variac and transformer. I don't know if such devices are made today but one might be found surplus/salvage. This type of line voltage regulator is probably more efficient than a ferroresonant transformer. A ferroresonant transformer consumes a significant percentage of its rated input current even when unloaded.

    I agree with the others that you cannot handle your situation with a fixed ratio transformer. You also cannot apply 188 volts to a nominal 120 volt input transformer without blowing fuses or burning out the transformer due to core saturation and resulting large primary currents.

    awright
     
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