Re: [EE] solid aluminum caps on 60hz

I have, but it was a long time ago so the details are a bit hazy.

I experienced interference on a nearby AM radio, IIRC the cure was to 
add a capacitor across the transformer secondary.

In some old schematics I think that I've sometimes seen capacitors wired 
across each of the diodes in a bridge rectifier circuit, presumably to 
fix the same issue.

John

On 15/05/2025 15:53, RussellMc wrote:
> BCCs: Re Prof Bogle.
>
> On Thu, 15 May 2025 at 20:04, Sean Breheny <[email protected]> wrote:
>
>> Hi Russell, Interesting datapoint - in my work on the EMC book, I did
>> experiments on
>> RFI from ordinary rectifiers. I was unable to generate any! I was able to
>> make big reverse recovery spikes but the dI/dt was too slow to produce
>> harmonics high enough to be radiated to any significant degree with
>> reasonable wire lengths. I had heard of this problem before but not
>> actually experienced it in line-frequency devices. Have you seen it "in the
>> wild"?
>>
> Sean (Sadly :-) ) I have not seen it happen myself.
> Memory says that I have heard of it happening but, as said memory now
> covers 60+years of playing, details may have been lost, or fabricated :-).
>
> However, it must be true :-) - the very great Professor A G Bogle told us
> so in about 1971.
> He founded the Auckland University Electrical Engineering department in
> 1969.
>
> " ... Professor Bogle, renowned for both his imposing intellect and his
> physical stature, completed his Bachelor of Electrical Engineering in 1935
> and a Bachelor of Mechanical Engineering the following year.
>
> He won a Rhodes Scholarship in 1937 and was accepted at Oriel College,
> Oxford. At Oxford, he worked towards a DPhil until the outbreak of World
> War II *when he joined the Admiralty team engaged in the development of
> radar systems*. He completed his doctorate at the Admiralty. ..."
>
> From:
> https://www.nzherald.co.nz/nz/emobituaryem-archibald-gordon-bogle/XDJD2NVWONSLSUJYH7SG45B25Q/#google_vignette
>
> Much more material:
> I could just maybe be in the photo on page 17(lecture theatre), but
> probably not.
> https://www.donovanimages.co.nz/media/projects/Vivat_low-res.pdf
>
>
>      Russell