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DC-AC Inverter for light loads

  1. Mar 9, 2017 #1


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    I have an alarm system that I would like to put on a UPS. Problem is the UPS that I've tried aren't very happy on the light load presented by the alarm. The power consumption is virtually zero unless the alarm is sounding. I think this is causing the UPS I have to generate a lot of noise that's messing with the alarm panel.

    The panel operates from a 220VAC to 9VAC mains adaptor. I've looked at a few options such as increasing the battery capacity in the alarm panel itself and feeding the panel something like 12-13V DC (which should go through it's bridge rectifier) but these introduce other problems.

    So what I'm looking for ideally is a 12V DC to 220V AC pure sine wave inverter that is stable on loads from 0 to say 50W. Do such things exist as I can't find one that specifically refers to light load operation.

    An alternative would be a 12V DC to 9VAC pure sine wave inverter.
  2. jcsd
  3. Mar 9, 2017 #2
    The class of UPS you need is called 'home network battery backup', like the BGE50/70/90 series.
    I'm sure it exists for 220V too.
  4. Mar 11, 2017 #3

    jim hardy

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    Pure sine is going to be expensive.

    This el-cheapo inverter will be happy at light load. Here in US it's under twenty bucks at Walmart, surely there's a 220 volt version in your country.

    If the problem is in your alarm panel, ie it's intolerant of a harmonic-rich power source, this inverter won't do your job. A snip from the manual:

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