Automatic ups circuit diagram

Discussion in 'General Electronics Chat' started by fayazahmedmemon, Jan 14, 2011.

  1. fayazahmedmemon

    Thread Starter New Member

    Jul 4, 2010
    I have made a 500 watt ups and it is working manually.i want to make the ups circuit fully automatic so that if wall outlet power goes off then it sarts to work and gives power and when wall outlet power comes back then it stops its working and begins to charge the battery.i am sending a schematic diagram so plz tell me how can i make it fully automatic with the use of relay or an other devicexplz send me the circuit diagram required.
  2. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
    That's not a schematic, it's only a very simple block diagram.
  3. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    No Bill, can't u see he had build it.
  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    If that is the way it is wired, there are some problems.

    You are using power out of the inverter (assuming the battery exists still), which means you are wasting at least 20% of the power from the outlet due to the step-down and step-up process. It's a waste of electricity. For every 100W-H you use, you will be paying for 120W-H or 140W-H.

    APC makes nice online UPS systems that switch within a millisecond and are rated for 20000VA and above. They cost around $5,000 for the higher rated, but 14000VA is only $90US.
  5. BillB3857

    AAC Fanatic!

    Feb 28, 2009

    WHERE? I'll take one!
  6. tom66

    Senior Member

    May 9, 2009
    It's important not to worry too much about switching time, as a modern computer power supply typically has a hold-up time (the time for which it can operate without input mains) of around 16 ms to 40 ms, at full load.
  7. SgtWookie


    Jul 17, 2007
    Why don't you start by posting the actual schematic for the inverter (rather than the functional diagram) and we'll progress from there?

    Basically, you'll need a relay that is 3PDT; or three-pole double-throw. You really don't need the inverter running when the AC is on. However, when the AC fails, you need a relay to disconnect both poles of the AC input, along with providing DC to the inverter - and transferring the load to the inverter output.