Rms & dc

[zesla]

In an AC transformer after Smoothing by the Smoothing electrolyte cap, the DC voltage would be almost equal to the peak value of the AC. So what is the meaning of this:
"The RMS value is the effective value of a varying voltage or current. It is the equivalent steady DC (constant) value which gives the same effect. "

In this state the DC must be equal to the peak not to the RMS or efective?

 

[BrownOut]

The "effective" DC level is not the peak level.
The "effective" DC level is the RMS level.
The rectified DC level is the peak level.

 

[zesla]

Thanks but What do you mean?
I did not say that the effective is equal to the peak!

Why You told about EFFECTIVE DC? Is not effective value related to AC?

 

[The Electrician]

In an AC transformer after Smoothing by the Smoothing electrolyte cap, the DC voltage would be almost equal to the peak value of the AC. So what is the meaning of this:
"The RMS value is the effective value of a varying voltage or current. It is the equivalent steady DC (constant) value which gives the same effect. "

In this state the DC must be equal to the peak not to the RMS or efective?

The RMS value of the AC voltage, before rectification, is not the same as the DC after rectification and smoothing. You would not expect the smoothed DC to have the same value as the RMS value of the unrectified AC.

 

[misterT]

The "effective" DC level is the RMS level.
The rectified DC level is the peak level.

That hurts.. so wrong.

 

[Reloadron]

In an AC transformer after Smoothing by the Smoothing electrolyte cap, the DC voltage would be almost equal to the peak value of the AC. So what is the meaning of this:
"The RMS value is the effective value of a varying voltage or current. It is the equivalent steady DC (constant) value which gives the same effect. "

In this state the DC must be equal to the peak not to the RMS or efective?

First, forget the smoothing capacitor.

What is being stated is that:

"The RMS value is the effective value of a varying voltage or current. It is the equivalent steady DC (constant) value which gives the same HEATING effect. "

If for example I have a 10 VDC source and light a lamp there will be a heating effect as the lamp emits heat. If I apply 10 volts AC peak (7.07 volts RMS) to that same lamp I will not get the same heating effect. However, if I apply 10 volts AC RMS I will get the same heating effect. Additionally I would need to apply 10 Volts RMS to have that same lamp draw the same current that it drew with 10 VDC. For some reason the statement did not include the word heating. Think about the work being done.

Therefore the RMS value of a good true sine wave is the DC equivalent.

Ron