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[wombat]

Wombat:
Ah, right! I'm hearing you, too. So you call it common-mode signal. But I'm still confused. You say the induced flux cancels the (reciprocating) currents. Agreed... to an extent. But wouldn't you say that winding the coil in each rail on a separate toroid would totally illiminate unwanted induced flux?
I'm still running on an L plate, don't forget.
BTW, you say Ken-T's unwanted sinewave is probably due to the inductance ringing with the suppression caps'. But what caps?... the one's, presumably, on his motor?... ESC?... Where?

Yep - I've got that stiff drink in me paw.
Hit me....

The way the toroid is working by using the interefernce to cancel itself out - it means that you can have a significantly lower inductance to get the same effect than if you used separate toroids to try and frilet the same effect. The other propbelm with comon mode noise is that it is not easy to find where the common point is so you cannot filter it out until it turns inmto a differential signal - at which point it is too late - because you need to have a separate ground to filter into. There is no point trying to filter line to line with common mode because the voltage on each will be the same.

It all gets very hairy I'm afraid - I have used common mode chokes only as a belt and braces approach when tryig to get a CE mark affixed to equipment. I am not fully up to speed with all the theory.

Now where's that drink

Tim the Wombat

[HS93 (RIP)]

The way I would look at this would be to bin the motors if they require that amount of suppression. a half decent pair of 545s with caps will only cost about £10 . and should give you trouble free boating. Peter

[Daryl]

Binning the motors is not an option for the reason below.
1/ Robbe still fits them into most of their boats, if there not much good they would have sorted it out by now..... Hopefully
2/ the previous owner fixed the gearboxes into the boat with resin and I don't fancy hacking it out just yet.
3/ the filters are standard Robbe equipment, (not available now) and are very much belt and braces.

Reading the above and talking to our techno boffins at work I'll replace the filters with Ye Olde capacitors and esc's.

Daryl

[HS93 (RIP)]

what I put was""if they require that amount of suppression""

[Doc]

PMK,
This is completely off topic so I'll keep it very short.  The 'LtDoc' is a nickname.  The 'Lt' refers to a rank and the 'Doc' to the fact that I delivered a couple of babies.  (One in an ambulace, the other in the back seat of a police car at a drive-in movie theatre...don't ask! LOL)
 - 'Doc

[OMK]

You know something, I'd swap my favourite gee-tar to see one of those drive-in movie theatres. We just don't got 'em here.
You Yanks got stlye!

PM heading your way......