DO YOU KNOW? Inverter conversion formula?

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?

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/>

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 <(E-Mail Removed)> 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

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/>

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 <(E-Mail Removed)> 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