dc equivalent of 240v rms

[ee01akk]

240v rms

Does anyone know how to find the dc equivalent voltage of 240V rms?
I need to know the required dc input voltage for an inverter to produce an ac output of 240V rms.
Thanks.

 

[tgq]

dc equivalent of ac

dc input of an inverter depends on the transformer inside :?
you can have 12Vdc input for 240Vac output :lol:
if the MOSETS or IGBTS are after the transformer you need minimum 240*1.414 + losses

 

[ee01akk]

dc equivalent

So 240*sqrt(2) is the dc equivalent. Isn't this the peak value of the ac as well?

 

[tgq]

ac dc equivalence

yes, if its sinusoid

 

[Shoaib]

240v ac rms

if u r using this thing for UPS or as replacement of AC 240 then keep in mind that output of inverter is not a sin wave, usually a square or triangular wave. Desigining a pure sin wave with output power of about 300 watts is quit difficult. a simple solution would be to design it for 460-480 volts and then user a stepdown transformer of (2:1) to conver it to required 240 volts. Or design for 260 volt and user a buffer transformer (1:1). this is chagne any squar or triangular wave to almost sin wave.

 

[bouteljea]

buffer transformer

RMS is the equivalent DC value for an AC signal.
i.e. A sinusiodal voltage with amplitude 339.41V has an RMS value of 240V
So your answer is 240V.

Briefly how it the RMS of a signal is found is:
1. Signal is squared (so that average is not zero)
2. Squared signal is averaged
3. Squared averaged signal is square rooted, in order to get the non zero "average" (for a non biased ac signal, the average in the true sense of the word is zero), or DC equivalent, hence RMS (Root Mean Square).

For a sinusoid, the relation between the amplitude and RMS is sqrt2 i.e. RMS = Vpeak / 1.4142

Look for RMS definitions on the net for a more detailed explanation.

 

[neuralc]

is 240v rms the same as 240v dc

240 v

HH
NeuralC

 

[bouteljea]

a cuanto equivalen 240 rms en watts

Hi again ee01akk.
Sorry, my last reply only intends answers your first question. As for the second question, it really depends on your design :wink: as also stated by tgq
Cool man, ciao