Window comparator as perfect rectifyer?

[FriedMule]

Imagine some standard run of the mill rectifier circuit with maybe 1V ripple, connect it to a zero droop window comparetor and last connect it to an opamp.
Let the opamp get power from the standard rectifier.
Would the opamp not try to keep it's output exactly as the comparetor's linear signal?

[Benta]

I'm not certain you really mean "window comparator".
Make a sketch of what you want, please.

[wraper]

Go google about synchronous rectification if meaning high efficiency power rectification or precision rectifier if you need a signal itself.
https://en.wikipedia.org/wiki/Active_rectification
https://en.wikipedia.org/wiki/Precision_rectifier
As of what you described is weird. And comparator has only 2 states on it's output, what linear signal? 

[FriedMule]

I'm not certain you really mean "window comparator".
Make a sketch of what you want, please.

What i mean is a circuit that detects highest positive voltage that the rectyfier is delivering, I do not know how to draw it but I'll try to explain again:-)
if you have that "max volt detector" and put the result into an opamp, the opamp will try it's best to deliver that as output.
My thought was that the end result will be an opamp that keep fighting to maintain the same max value.

Go google about synchronous rectification if meaning high efficiency power rectification or precision rectifier if you need a signal itself.
https://en.wikipedia.org/wiki/Active_rectification
https://en.wikipedia.org/wiki/Precision_rectifier
As of what you described is weird. And comparator has only 2 states on it's output, what linear signal? 

Great links, it looks like what I am thinking of!
Am I wronh in thinking that this circuit: https://upload.wikimedia.org/wikipedia/commons/c/ca/Op-Amp_Precision_Rectifier_%28Improved%29.svg
only is a half-bridge rectifier?
And combined with the comparator, it gets to be a full bridge rectifier?

Hmm does it not loose a lot power in that configuration?

[wraper]

Peak detector is not a comparator. Also it does not help at rectifying in any way.

[wraper]

Am I wronh in thinking that this circuit: https://upload.wikimedia.org/wikipedia/commons/c/ca/Op-Amp_Precision_Rectifier_%28Improved%29.svg
only is a half-bridge rectifier?
And combined with the comparator, it gets to be a full bridge rectifier?

Hmm does it not loose a lot power in that configuration?

Comparator again... Add another diode and opamp and you will have full wave rectifier.

[FriedMule]

Thanks a lot!

I have only seen something that is called window comparator, where it detects if peak voltage is above or below trigger voltage and have that voltage stored
So my thought was to let the "window" be configured so that it only triggers with max voltage i.e. 5V and send these 5V to the opamp.

But your drawing is fare better, thanks.

[wraper]

I have only seen something that is called window comparator, where it detects if peak voltage is above or below trigger voltage and have that voltage stored

Window comparator basically is just two regular comparators set to different voltage + AND logic. It does not store anything and it does not have anything to do with peak voltage. Usual comparator only detects if signal is above/below set level. Window comparator detects if it is within certain range or not. One comparator is set to maximum level, another to minimum level.
https://en.wikipedia.org/wiki/Window_detector

So my thought was to let the "window" be configured so that it only triggers with max voltage i.e. 5V and send these 5V to the opamp.

Strange logic. So you idea "works" (it doesn't) only if input voltage is already is known. Why then bother rectifying anything at all?

[Benta]

A Window Comparator is an array of comparators coupled to combinatorial logic.
As an example:
Analog input voltage 0...5 V
0...<1 V: output 1 active
1...<2 V: output 2 active
2...<3 V: output 3 active
3...<4 V: output 4 active
4...5 V: output 5 active

Relating that to a rectifier is difficult at best...

[FriedMule]

I am glad for your help, can't find the video where the window comparator was presented in the wrong way.
As I am a noob, I tend to believe in the videos I find, but thanks to you, I'd learn that nothing all is true:-)

[FriedMule]

I was trying to play with the circuit, just to learn but the online simulator is confusing me big time: http://tinyurl.com/y4jcz686
1VAC in 15VDC out

[Audioguru]

Your opamps have no part number and no power supply voltage so they will not work.
The second opamp has positive feedback so if there is a tiny positive input to it then its output will go as high as it can and stay like that (even if the input signal stops) until the power supply is turned off.
I guess the supply is +15V and the opamp is "rail to rail" allowing its output to go as high as +15V.

[FriedMule]

Your opamps have no part number and no power supply voltage so they will not work.
The second opamp has positive feedback so if there is a tiny positive input to it then its output will go as high as it can and stay like that (even if the input signal stops) until the power supply is turned off.
I guess the supply is +15V and the opamp is "rail to rail" allowing its output to go as high as +15V.

Oh thanks a lot, it makes sense, no the AC is 1V.
But I'll change the errors:-)

[FriedMule]

Am I wronh in thinking that this circuit: https://upload.wikimedia.org/wikipedia/commons/c/ca/Op-Amp_Precision_Rectifier_%28Improved%29.svg
only is a half-bridge rectifier?
And combined with the comparator, it gets to be a full bridge rectifier?

Hmm does it not loose a lot power in that configuration?

Comparator again... Add another diode and opamp and you will have full wave rectifier.

I have redrawen my circuit (read stolen a solution)
You show two examples and here is a third: http://tinyurl.com/y3yhr8kt

But how do I know what to choose, what is the difference?