Multiple switch mode power supplies

Apr 09, 2012 8 Replies

Hopefully a hypothetical assuming cannot repair a small SMPS in a 1U case. Assuming 3 of those little "plug-top" , I don't know the generic name, "phone charger" SMPS can have the usual fudge of changing 2 or 3 resistors each to give +/- 15V, .2A and 5V , .5A and mains safety issues taken into account. Would there be an EMC or cross-coupling problem due to 3 free-running oscillator SMPS running inside one box, often the case that 3 would be togrther in close proximity charging 3 phones at the same time.


It's unlikely their transformers would have sufficient stray flux to produce interference.

If you're worried, position two of them at right angles, and the third not-in-line with either.

Please learn how to write a short, simple, declarative sentence! Learning how will give you a great sense of satisfaction.

uce

Mr. Cook's question was stated just fine, we have some grouches here this Monday morning.

There is a slight chance that the oscillators would try to sync up, it depends on how close they are in free-running frequency and also on how much intercoupling there is between the electronics, as well as any possible flux coupling between the transformers. Really hard to predict!

"hr(bob) = google monkey

Mr. Cook's question was stated just fine,

** Only fine if you are an autistic, dyslexic f****it.

There is a slight chance that the oscillators would try to sync up,

** Like there is a slight chance the moon is made of green cheese.

F*ck off - moron.

produce

Mr. Cook's question was stated just fine, we have some grouches here this Monday morning.

There is a slight chance that the oscillators would try to sync up, it depends on how close they are in free-running frequency and also on how much intercoupling there is between the electronics, as well as any possible flux coupling between the transformers. Really hard to predict!

++++

So keep as separate as possible and perhaps 120/120/120 degree relative orientations and inversion if 2 are constrained to be close, makes sense to reduce that likelihood

I the it any way reader let and right you it's like ? So all to write guess unscramble

Mr Cook, PLEASE LEARN HOW TO WRITE simple, clear sentences. It's a necessary skill. When someone offers you sound advice, don't ignore it.

"William Sommerwerck"

** ROTFL !!

( see, I do say nice things sometimes .. )

.... Phil

So why do you get so angry? Is it psychosis? Or are you just playing the "angry old man"?

It's okay to criticize. You don't have to jump down people's throats doing it.

Hey Phil !!

Are you Ok man ?? I'm getting worried about ya :-)

Rheilly P

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