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Re: Remote power supplies

Posted: Sat Sep 07, 2019 2:43 pm
by _D_S_J_R_
Try shielding them first. Loads of wonderful amps out there with built in transformers in my experience.

Re: Remote power supplies

Posted: Sat Sep 07, 2019 3:01 pm
by karatestu
_D_S_J_R_ wrote: Sat Sep 07, 2019 2:43 pm Try shielding them first. Loads of wonderful amps out there with built in transformers in my experience.
I agree. Trouble with shielding is that EMI goes right through most metals. Steel is better than aluminum or copper and thicker the better.Cast iron may be even better than steel. Mumetal often gets mentioned but its expensive

Re: Remote power supplies

Posted: Sat Sep 07, 2019 8:46 pm
by keepitsimplestupid
Stu I can only give advice based on experience as I'm not that well read on the subject.

For the paradise all the heavy lifting in the psu is done in a separate case. This is connected by a four way lead .74mm quad core, carrying only + ' 300mA at 27v. In the phono box is a local shunt reg. Theres a measurable difference in psu noise if I add local decoupling, only 50uf at the ends of the cables just before the shunt. Cable Inductance effects are present even on short, 60cm leads, so adding the last cap in the mains filter right next to the load is a good bit of design. Even though the cables are short and about 10x thicker than current requirements dictate.

Itll be different for every circuit so simulation or measurement is required for best results.

Re: Remote power supplies

Posted: Sun Sep 08, 2019 1:03 am
by karatestu
Thanks for sharing your experience Simon.

I don't do measurements except with a dmm, ruler or my ears. Don't own a sillyscope and wouldn't know how to use it properly. I often think of borrowing the one doing the rounds on pfm but it would take me a month to actually learn to use it and be sure i was measuring properly.

Re: Remote power supplies

Posted: Sun Sep 08, 2019 3:46 pm
by keepitsimplestupid
I found a decent resource on osciloscope techniques hard to fine, ended up asking an old lag how to and went from there.