DO YOU KNOW? Inverter conversion formula?

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

1. DaveGuest

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

2. SoerenGuest

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
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

3. Bill DardenGuest

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
> Inverter effiency 70%
>
> Input current = 50VA / (12 * 0.7) = ~6A

Bill Darden, Jun 6, 2004
4. SoerenGuest

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
5. DaveGuest

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