Is this filter response normal ?

Thread Starter

AlexLPD

Joined Aug 22, 2010
60
TP- I guess the question I have is- what are you trying to accomplish? A pure/clean 60Hz signal?
I'm trying to block all the 60hz signal.
The main idea is to "Inject" a signal for each one of the 3phases. So I can distinguish the A B and C.

The first part of the problem is to block all 60hz signal.
https://forum.allaboutcircuits.com/threads/amplify-a-khz-signal-over-the-mains-ac-to-turn-on-a-led-amplify-stage.162725/#post-1434452

This was the main idea on the OP.
Thanks for the insigths.
-Alex.
 

Thread Starter

AlexLPD

Joined Aug 22, 2010
60
All rigth... So, mind me some questions.
The first transformer is an isolation As is 1:1. Sorry I can't find the AAC rules.
The cond transformer is made with a ferrite core ring about 20mm in diameter. At 1mH it seems doable, let me search in the junk box, or the scrap to see If I can find some ferrite cores.
-Alex
 

Danko

Joined Nov 22, 2017
917
The main idea is to "Inject" a signal for each one of the 3phases. So I can distinguish the A B and C.
You can not isolate signal in one phase, because of capacitance between phases and low inner resistance of consumer devices on 3-phase line. It will spread over all phases.
 

Thread Starter

AlexLPD

Joined Aug 22, 2010
60
You can not isolate signal in one phase, because of capacitance between phases and low inner resistance of consumer devices on 3-phase line. It will spread over all phases.
I think the meter I saw uses a two filters to spot the spreading.
One to gnd of the ac circuit, and one from the neutral line. Thus I believe make the effect of open the circuit in this areas..
 

DickCappels

Joined Aug 21, 2008
6,312
If you scroll all the way down to the very bottom of the page the black border, on the very last line is a series of links: Privacy Policy - Terms of Service - User Agreement

To broadly summarize the User Agreement as it relates to this thread, it says that transformerless power supplies are not allowed (and this is not one of those) and don't do anything else dangerous or that will be the end of the discussion. Everybody on this site has agreed to the Terms of Service which includes the User Agreement. Members on this thread are working to help keep you safe as well as help you find the solutions you seek.

-end of digression
 

Thread Starter

AlexLPD

Joined Aug 22, 2010
60
slow day over here, so went out and look for the FFT on the scope, sure its handy and sure I have not seen on my scope for my particular transformer, will do it in the nigth after the sport.

I leave this handy dandy video when it shows a litte bit more specific;

Very interesting to know the harmonics on the transformer.
-Alex.
 
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