DO YOU KNOW? Inverter conversion formula?

Discussion in 'Electronic Basics' started by Dave, Jun 4, 2004.

  1. Dave

    Dave Guest

    Just curious if there is a set formula for calculating how many amps a
    12 volt car inverter draw from battery given the load of an AC device?
    Dave, Jun 4, 2004
    #1
  2. Dave

    Soeren Guest

    Hi Dave,


    > Just curious if there is a set formula for calculating how many amps a
    > 12 volt car inverter draw from battery given the load of an AC device?


    Input current = output power / (input voltage * inverter efficiency)

    Eg.
    Input 12V_DC
    Output Load 50VA ("RMS")
    Inverter effiency 70%

    Input current = 50VA / (12 * 0.7) = ~6A


    --
    Regards,
    Soeren

    * If it puzzles you dear... Reverse engineer *
    New forum: <URL:http://www.ElektronikTeknolog.dk/cgi-bin/SPEED/>
    Soeren, Jun 4, 2004
    #2
  3. Dave

    Bill Darden Guest

    Please see Section 7.9 in the Car and Deep Cycle Battery FAQ on
    www.batterfaq.org for inverter, battery and charger sizing.

    Kindest regards,

    BiLL......

    Soeren <> wrote in message news:<Xns94FECE9ECF3EAo8oLOOKatHOMEo8o@212.242.40.196>...
    > Hi Dave,
    >
    >
    > > Just curious if there is a set formula for calculating how many amps a
    > > 12 volt car inverter draw from battery given the load of an AC device?

    >
    > Input current = output power / (input voltage * inverter efficiency)
    >
    > Eg.
    > Input 12V_DC
    > Output Load 50VA ("RMS")
    > Inverter effiency 70%
    >
    > Input current = 50VA / (12 * 0.7) = ~6A
    Bill Darden, Jun 6, 2004
    #3
  4. Dave

    Soeren Guest

    Hi Bill,


    > Please see Section 7.9 in the Car and Deep Cycle Battery FAQ on
    > www.batterfaq.org for inverter, battery and charger sizing.


    I guess you mean www.batterYfaq.org :)

    <URL:http://www.uuhome.de/william.darden/carfaq7.htm#backup>


    What do you want me to see there ? Hopefully not something that
    disagrees with proven formulas ?


    --
    Regards,
    Soeren

    * If it puzzles you dear... Reverse engineer *
    New forum: <URL:http://www.ElektronikTeknolog.dk/cgi-bin/SPEED/>
    Soeren, Jun 7, 2004
    #4
  5. Dave

    Dave Guest

    Does this equation apply for an 120VAC device plugged into the 12V_DC
    inverter?

    Is the equation different for resistive and inductive loads?

    Being new to the terminology, is VA truly equal to Watts?

    So lets say I have a TV plugged into my inverter: needs 120VAC of
    course and draws who knows, 1.2 amps. Would the above equation apply?

    Dave

    Soeren <> wrote in message news:<Xns94FECE9ECF3EAo8oLOOKatHOMEo8o@212.242.40.196>...
    > Hi Dave,
    >
    >
    > > Just curious if there is a set formula for calculating how many amps a
    > > 12 volt car inverter draw from battery given the load of an AC device?

    >
    > Input current = output power / (input voltage * inverter efficiency)
    >
    > Eg.
    > Input 12V_DC
    > Output Load 50VA ("RMS")
    > Inverter effiency 70%
    >
    > Input current = 50VA / (12 * 0.7) = ~6A
    Dave, Jun 8, 2004
    #5

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