Kurt, you certainly nailed the typical sequence of events. For those of
you who have never been in the designer or retrofit shoes of the engineers,
take Kurt's contribution as gospel! It's real as described, and many times
even worse with problems being simply swept under the rug or directed by
management to be ignored. And W9IP's observation is also gospel. It's all
about money these days, not quality or obeying the radiated emission laws.
There is another enemy in the stewing pot of RFI soup: the contract
manufacturer. The source company may come up with a fix for something and
passed one or three units through regulatory testing, but when passed on to
the CM, most of the EMC/RFI components are removed and jumpers installed.
Typically the RFI/EMC components contribute nothing to the performance of
the product only add cost. So, the CM doing what CMs do, reduce cost, the
components are removed. I've seen this so many times in the past 20
years. China is particularly guilty of this practice.
Yet another ingredient to the stewing pot of RFI soup: China. I seriously
doubt there are but 1% of SMPSs designed and built in the US. China is
pretty much the single source of SMPSs and SM controllers in all their
incantations. We all are aware of where China stands wrt EMC/RFI - they
don't care and cheat at every possible opportunity.
Yet another ingredient to the stewing pot of RFI soup: Our very own FCC.
Those SMPSs from China sail through Customs as a "component" with no
attention paid to regulatory testing. And further, they are installed in
all our appliances. And.....our very own FCC exempts appliances for any
EMC/RFI evaluation other than to point out "to use best engineering
practices"
No wonder SMPSs in all their themes and variations are an ongoing and
increasing problem.
Dave - WØLEV
On Wed, Feb 8, 2023 at 6:57 AM KD7JYK DM09 <kd7jyk@earthlink.net> wrote:
> On 2/7/2023 18:55, NA6MB Mike wrote:
> > They have been “working on” a new system / quieter system for several
> years now!
>
> When I worked in prototyping, we had a fellow, that designed switching
> mode power supplies. From idea, to design, to completed project, was
> about three months, and most of that was waiting for others with
> monstrous backlogs. In reality, it took about a week for him to come up
> with a design. That was one guy, 23+ years ago, and having to hire out
> for assembly, compliance testing, and certification.
>
> I recall one time when an on-board supply didn't pass, another fellow
> had to come up with a patch, and instructions for me to build/verify
> before sending it to the manufacturer. That took about five hours,
> three before lunch, two after, and about a half-dozen attempts. Once
> verified, the fellow grabbed the modification sheet and ran out of the
> lab. I heard no more, the supply was perfect.
>
> I'd imagine, nowadays, with the personnel, and resources of an average
> sized company, much more than a week or two for a solution, maybe a
> month at the outside, with most of that just standing around, is purely
> jerking people around, waiting for someone else's problem to go away.
>
> A fellow asked earlier about the model, or information regarding a new
> quiet system. It hardly matters. If quiet, then all new ones will be
> quiet from the first quiet new build onward, the problem will no longer
> exist. If an old one isn't, the replacement will be quiet, once the
> manufacturer is notified of an issue, as all they will have on-hand is
> quiet replacement units.
>
> Should a quiet system actually exist, perfect, problem solved- FOREVER.
>
> Quiet modules won't be back-engineered into RFI spewing problematic
> garbage, and noisy units will fail, or get swapped out upon
> notification, so, ultimately, in the end, RFI silence.
>
> I wouldn't hold my breath, rely on it, or even imagine there being a
> valid solution, or it would have existed within days, to weeks of the
> issue coming up, and, so far, based on comments in the forums, as
> recently as the last one, solar edge has had RFI problems since their
> inception. If you have solar edge based RFI, and had just one guess as
> to why, you'd almost certainly be right:
>
> The issue exists, because a solution does not.
>
> Kurt
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>
--
*Dave - WØLEV*
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