Wrap twisted pair wires in metal foil to shield them?

[cupoftea]

Hi,
My previous question was “saturated”, so please may I ask again here...
Previous question:
https://www.edaboard.com/threads/forgot-to-track-ramp-signal-back-to-pfc-controller.403348/

I need to track ramp signals from the FET driver sub-PCB to the PFC controller sub-PCB in a 2kW interleaved Boost PFC, as attached. (I forgot to track the ramp signals on the main PCB when I layed it out). The “ramp” signals are effectively like “slope compensation”.

If I do the attached twisted pair wiring, then will it be better shielded from noise if I wrap the twisted pairs in thin aluminium foil. (like baking foil)?

Or would it be better to just use some flexible coax cable?

 

[crutschow]

Better to use coax with the shield grounded.

 

[FvM]

Don't know how a question can be "saturated"? In my view it's just an ordinary duplicated content forum rule violation. You have a new question about foil shielding, why didn't you add it to the previous thread instead of redundantly repeating most of the old content?

 

[cupoftea]

My apologies , i felt the "previous question" ...i stupidly droaned on too much about the ramp signal, which to be honest, requires some considerable time of UCC28070A datasheet analysis...which i thought many people would not have time for......so in this new question, i presented it as a mere "noisy connection question", something that i thought may be more answerable to many. I have to confess that i find a very short question, tends to be more likely answered....but if its placed at the bottom of a number of threads, then it often goes unanswered.

Though Crutshchow has offered a great answer, in the coax, which i think is what i will use now......it is a strange thing i sometimes find....sometimes framing a question, and formally writing it down on the forum, even helps one to answer the question oneself at times.

I always try and make the question title relevant....so that people googling it may get directed to this forum, to increase forum traffic, which i assume is beneficial for the forum owners.

I do feel sorry for many engineers, who are in companies where seniors "hawk watch" the forums, so as to spot fellow employees who are writing to forums...and then they stop them doing it.......on the excuse that its giving away company secrets.....when in fact its more about making sure junior colleagues dont get knowledgable, and remain "junior" to the seniors in knowledge. Ive even worked places where people writing questions about bog standard electronics were accused of giving away company secrets.
And of course, i have worked in many co's who suffered large number of recalled products...and if only someone had written for forum advice, then it would never have happened.

I myself was once summonsed to court for a simple question about an offtheshelf power module. An ex colleague was reprimanded for asking about a chargepoint... which is pretty much a "relay on a PCB"....certainly not some rocket science secret...anyway i digress.

 

[cupoftea]

I picked these two coax's for the bit of coax, but can you think of a better/cheaper piece?

Farnell 3862337

https://uk.farnell.com/molex/73116-0003/cable-assy-mcrf-plug-mcrf-plug/dp/3862337?ost=3862337

Farnell 2096226

https://uk.farnell.com/lprs/rg174-300mm/cable-rg174-300mm/dp/2096226?ost=2096226

We will cut the connectors off and just solder inner and outer to PCB.