Discussing a design with colleagues and two excellent references provided.
Passing them along -- in case others find themselves in the same boat...

<http://lesliegreen.byethost3.com/articles/solenoids.pdf>

<https://ia801609.us.archive.org/12/items/in.ernet.dli.2015.205551/2015.205551.Electromagnetic-Devices.pdf>

On Wednesday, June 23, 2021 at 2:26:35 PM UTC-4, Don Y wrote:
> Discussing a design with colleagues and two excellent references provided.
> Passing them along -- in case others find themselves in the same boat...
>
> <http://lesliegreen.byethost3.com/articles/solenoids.pdf>
>
> <https://ia801609.us.archive.org/12/items/in.ernet.dli.2015.205551/2015.205551.Electromagnetic-Devices.pdf>

A nearly 600 page textbook from 1941? Which parts did you find most useful?

On 6/23/2021 11:38 AM, Fred Bloggs wrote:
> On Wednesday, June 23, 2021 at 2:26:35 PM UTC-4, Don Y wrote:
>> Discussing a design with colleagues and two excellent references provided.
>> Passing them along -- in case others find themselves in the same boat...
>>
>> <http://lesliegreen.byethost3.com/articles/solenoids.pdf>
>>
>> <https://ia801609.us.archive.org/12/items/in.ernet.dli.2015.205551/2015.205551.Electromagnetic-Devices.pdf>
>
> A nearly 600 page textbook from 1941? Which parts did you find most useful?

Do you think wire and iron have changed in the 80 years since?
Do you think the physics of electromagnetism have changed?

Find me a similarly comprehesive test from say the past *20* years
(and make sure it doesn't reference THIS one!)

On Wednesday, June 23, 2021 at 2:55:40 PM UTC-4, Don Y wrote:
> On 6/23/2021 11:38 AM, Fred Bloggs wrote:
> > On Wednesday, June 23, 2021 at 2:26:35 PM UTC-4, Don Y wrote:
> >> Discussing a design with colleagues and two excellent references provided.
> >> Passing them along -- in case others find themselves in the same boat...
> >>
> >> <http://lesliegreen.byethost3.com/articles/solenoids.pdf>
> >>
> >> <https://ia801609.us.archive.org/12/items/in.ernet.dli.2015.205551/2015.205551.Electromagnetic-Devices.pdf>
> >
> > A nearly 600 page textbook from 1941? Which parts did you find most useful?
> Do you think wire and iron have changed in the 80 years since?
> Do you think the physics of electromagnetism have changed?
>
> Find me a similarly comprehesive test from say the past *20* years
> (and make sure it doesn't reference THIS one!)

There's now electronically enhanced technology for one thing:
https://www.emerson.com/en-us/automation/brands/asco/solenoid-valve-technology

On 6/23/2021 1:03 PM, Fred Bloggs wrote:
> On Wednesday, June 23, 2021 at 2:55:40 PM UTC-4, Don Y wrote:
>> On 6/23/2021 11:38 AM, Fred Bloggs wrote:
>>> On Wednesday, June 23, 2021 at 2:26:35 PM UTC-4, Don Y wrote:
>>>> Discussing a design with colleagues and two excellent references provided.
>>>> Passing them along -- in case others find themselves in the same boat...
>>>>
>>>> <http://lesliegreen.byethost3.com/articles/solenoids.pdf>
>>>>
>>>> <https://ia801609.us.archive.org/12/items/in.ernet.dli.2015.205551/2015.205551.Electromagnetic-Devices.pdf>
>>>
>>> A nearly 600 page textbook from 1941? Which parts did you find most useful?
>> Do you think wire and iron have changed in the 80 years since?
>> Do you think the physics of electromagnetism have changed?
>>
>> Find me a similarly comprehesive test from say the past *20* years
>> (and make sure it doesn't reference THIS one!)
>
> There's now electronically enhanced technology for one thing:
> https://www.emerson.com/en-us/automation/brands/asco/solenoid-valve-technology

None of that affects the *physics* involved. I can replace an "end of stroke"
switch with a timer or a dynamic measurement of current over time -- but those
are just efficiency hacks.

Why not TRY designing one and see what information YOU go in search of?
Or, you can continue to sit and play Monday morning quarterback while some
of us actually dig into these technologies...

Paraphrasing Shaw: "Those who can, do!"

On Wednesday, June 23, 2021 at 2:26:35 PM UTC-4, Don Y wrote:
> Discussing a design with colleagues and two excellent references provided.
> Passing them along -- in case others find themselves in the same boat...
>
> <http://lesliegreen.byethost3.com/articles/solenoids.pdf>
>
> <https://ia801609.us.archive.org/12/items/in.ernet.dli.2015.205551/2015.205551.Electromagnetic-Devices.pdf>
thank you for the pointers.
I liked both the extensive theoretical underpinnings (more than my undergrad covered) as well as the practical design examples.

On 6/23/2021 1:36 PM, Three Jeeps wrote:
> I liked both the extensive theoretical underpinnings (more than my undergrad
> covered) as well as the practical design examples.

I was blown away by how they seemed to *anticipate* every issue that
I had to address.

When I get back home (traveling), I need to spend some time CAREFULLY
studying them.

On Thursday, June 24, 2021 at 4:55:40 AM UTC+10, Don Y wrote:
> On 6/23/2021 11:38 AM, Fred Bloggs wrote:
> > On Wednesday, June 23, 2021 at 2:26:35 PM UTC-4, Don Y wrote:
> >> Discussing a design with colleagues and two excellent references provided.
> >> Passing them along -- in case others find themselves in the same boat...
> >>
> >> <http://lesliegreen.byethost3.com/articles/solenoids.pdf>
> >>
> >> <https://ia801609.us.archive.org/12/items/in.ernet.dli.2015.205551/2015.205551.Electromagnetic-Devices.pdf>
> >
> > A nearly 600 page textbook from 1941? Which parts did you find most useful?
>
> Do you think wire and iron have changed in the 80 years since?

There are lot more hard and soft ferromagnetic alloys around now. Sintering has got more popular.
> Do you think the physics of electromagnetism have changed?

No, but the range materials that show ferromagnetic behavior has expanded quite a lot
> Find me a similarly comprehensive text from say the past *20* years (and make sure it doesn't reference THIS one!).

There isn't a large market for this kind of text.

--
Bill Sloman, Sydney

On Wed, 23 Jun 2021 11:55:26 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:

>On 6/23/2021 11:38 AM, Fred Bloggs wrote:
>> On Wednesday, June 23, 2021 at 2:26:35 PM UTC-4, Don Y wrote:
>>> Discussing a design with colleagues and two excellent references provided.
>>> Passing them along -- in case others find themselves in the same boat...
>>>
>>> <http://lesliegreen.byethost3.com/articles/solenoids.pdf>
>>>
>>> <https://ia801609.us.archive.org/12/items/in.ernet.dli.2015.205551/2015.205551.Electromagnetic-Devices.pdf>
>>
>> A nearly 600 page textbook from 1941? Which parts did you find most useful?
>
>Do you think wire and iron have changed in the 80 years since?
>Do you think the physics of electromagnetism have changed?
>
>Find me a similarly comprehesive test from say the past *20* years
>(and make sure it doesn't reference THIS one!)

When I was looking at magnetic shielding a few years ago, the most
useful references were from that era.

--
Best regards,
Spehro Pefhany

Fred Bloggs <bloggs.fredbloggs.fred@gmail.com> wrote:
> On Wednesday, June 23, 2021 at 2:26:35 PM UTC-4, Don Y wrote:
>> Discussing a design with colleagues and two excellent references provided.
>> Passing them along -- in case others find themselves in the same boat...
>>
>> <http://lesliegreen.byethost3.com/articles/solenoids.pdf>
>>
>> <https://ia801609.us.archive.org/12/items/in.ernet.dli.2015.205551/2015.205551.Electromagnetic-Devices.pdf>
>
> A nearly 600 page textbook from 1941? Which parts did you find most useful?

Maybe he found a section about "electrical pressure" and diameter of
double cotton coated and silk insulated wire lookup tables. Real handy
when having a coil wound these days.

On 6/24/2021 8:57 AM, Spehro Pefhany wrote:
> On Wed, 23 Jun 2021 11:55:26 -0700, Don Y
> <blockedofcourse@foo.invalid> wrote:
>
>> On 6/23/2021 11:38 AM, Fred Bloggs wrote:
>>> On Wednesday, June 23, 2021 at 2:26:35 PM UTC-4, Don Y wrote:
>>>> Discussing a design with colleagues and two excellent references provided.
>>>> Passing them along -- in case others find themselves in the same boat...
>>>>
>>>> <http://lesliegreen.byethost3.com/articles/solenoids.pdf>
>>>>
>>>> <https://ia801609.us.archive.org/12/items/in.ernet.dli.2015.205551/2015.205551.Electromagnetic-Devices.pdf>
>>>
>>> A nearly 600 page textbook from 1941? Which parts did you find most useful?
>>
>> Do you think wire and iron have changed in the 80 years since?
>> Do you think the physics of electromagnetism have changed?
>>
>> Find me a similarly comprehesive test from say the past *20* years
>> (and make sure it doesn't reference THIS one!)
>
> When I was looking at magnetic shielding a few years ago, the most
> useful references were from that era.

There are roughly three different types of books in my collection:
- classics (texts that were key in their fields, likely still very
relevent, even if only to put things in historical perspective)
- time-invariant (texts that address issues that don't appreciably
change, over time or with such small "readerships" that there is
very little "churn" in publications of their sort)
- current/trendy books that follow "fads" (that likely won't have
long enough legs to ever become either of the previous two
categories)

I don't have any books that address current techniques, "how-to",
etc. as something else likely already has taught me the basics
for <whatever> and the "how-to" will change from year-to-year
(version to version), etc. An early employer taught me that!

Classics easily go back three or more decades. Knuth's "Tex" (84)
and "Art Of" (68) serieses obviously fit the bill. As does
Organick's text (72). And, who doesn't have Stevens (~93) or
Tanenbaum (~86) in their collection? Or Winston (~76)?

["My god! How can ANYTHING still be pertinent after 40-50 years, esp
when dealing with something as volatile as computers???" <rolls eyes>]

*Nothing* can touch Klatt's explanation (87) about the issues involved
in text-to-speech conversion. Similarly, Northcutt's (87) description
of Alpha. Or Little's (49) incredibly dense treatment of tabletting.
Or Hoare's CSP (85).

I've got a book on ECCs (61) from Peterson that I frequently find myself
consulting as it is far more comprehensive (and suffers less "bloat")
than more modern treatments (which typically are tie-ins to existing
implementations).

I hang onto Drake's Probability text (67) to remind me of the types of
mistakes I can make when determining the reliability of a protocol,
likelihood of a disturbance, etc. Freund's stat book (52) to similarly
"keep me honest".

Similarly, several crypto texts to keep me from making the sorts of
mistakes folks without any schooling often make in implementations.
(But, I suspect I could toss most and just cling to Schneier's (93)
without risking losing too much -- esp as the field isn't as static
as one would have hoped!). And, of course, the Abstract Algebra
texts (which don't seem to be in their correct places on my shelf!)
when I need to remember the properties of groups, rings, fields, etc.
(esp wrt crypto theory)

Mick & Brick (80) has a special place on my shelf as it inspired much of
my early CPU designs. And, Meade & Conway when I was doing customs.
I have an ancient "math" book (43) that has lots of "manual techniques" for
performing operations that are no longer taught in such a terse form.

I have a delightfully terse little book (51) that reminds me of the uses
for the various scales on sliderules. Nostalgia?

Laziness keeps me from discarding my books on control theory, SPC, etc.
And, I should probably purge most of my *other* hardware-related texts
as the trend is for simpler and smaller designs, nowadays (let someone
else integrate all of the functionality you want -- AND MORE -- and
just buy it prepackaged!).

[Though, having said that, I've found myself having to brush off some
texts to remind myself of the theory involved in "radio" as I've been
working on several SDR implementations]

The texts on grounding/shielding/ESD are probably worth holding onto as
that's largely time-invariant (and easier to pick up in a text book than
some wikipedia page!)

There are books on (at least!) 30 different programming *languages* that
I'd consider in the "fads" category. When was the last time you wrote
code in Mumps? Or APL? OTOH, they don't take up *that* much space
(I could always scan them and discard the originals but the shelf space
takes less time! :> ) and there are times when I do have to revisit some
"dead" language (I had to relearn SNOBOL to ensure I ported something
correctly a few years back).

And, lots of "opinion pieces" on UI design, "best practices" in various
fields, system validation, etc.

The "books-by-the-pound" so common in recent offerings are usually not
worth cracking the binding to examine!

Hopefully, I can purge ALL of this from the shelves in a few more years
to make way for *different* material! (exciting!!!)

On Wed, 23 Jun 2021 11:55:26 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:

>On 6/23/2021 11:38 AM, Fred Bloggs wrote:
>> On Wednesday, June 23, 2021 at 2:26:35 PM UTC-4, Don Y wrote:
>>> Discussing a design with colleagues and two excellent references provided.
>>> Passing them along -- in case others find themselves in the same boat...
>>>
>>> <http://lesliegreen.byethost3.com/articles/solenoids.pdf>
>>>
>>> <https://ia801609.us.archive.org/12/items/in.ernet.dli.2015.205551/2015.205551.Electromagnetic-Devices.pdf>
>>
>> A nearly 600 page textbook from 1941? Which parts did you find most useful?
>
>Do you think wire and iron have changed in the 80 years since?
>Do you think the physics of electromagnetism have changed?
>
>Find me a similarly comprehesive test from say the past *20* years
>(and make sure it doesn't reference THIS one!)

These are great references and books.

The more, the better !

Thanks Don !

On 27/06/2021 08:11, boB wrote:
> These are great references and books.
>
> The more, the better !
>
> Thanks Don !
>
+1 Thanks
It reminded me of early loudspeakers where the electromagnet
was cleverly used as a filter choke.
Early permanent magnets were known to loose strength with time.

On Friday, July 2, 2021 at 2:20:36 PM UTC-7, bilou wrote:

> Early permanent magnets were known to loose strength with time.

Oh, it's worse than that; in physics lab, we spread ALL our bar magnets out, covered 'em
with some paper, and sprinkled iron filings over. There were some with five poles,
some with three, and... we tried to do the experiments with only the two-pole
types. I think the red-paint-end DID kinda indicate polarity.

Mechanical stress (hammer blow) is one way of creating a magnet. Or re-creating it.
Applying a 'keeper' (magnetic short circuit) was considered good storage practice
for a permanent magnet. Apparently, just dropping 'em into a cigar box isn't good
storage practice.

On 7/2/2021 2:20 PM, bilou wrote:
> On 27/06/2021 08:11, boB wrote:
>> These are great references and books.
>>
>> The more, the better !
>>
>> Thanks Don !
>>
> +1 Thanks
> It reminded me of early loudspeakers where the electromagnet
> was cleverly used as a filter choke.

That's how many (low cost) Class D designs, today, operate.

> Early permanent magnets were known to loose strength with time.

On 3.7.2021 06:15 AM, Don Y wrote:
> On 7/2/2021 2:20 PM, bilou wrote:
>> On 27/06/2021 08:11, boB wrote:
>>> These are great references and books.
>>>
>>> The more, the better !
>>>
>>> Thanks Don !
>>>
>> +1 Thanks
>> It reminded me of early loudspeakers where the electromagnet
>> was cleverly used as a filter choke.
>
> That's how many (low cost) Class D designs, today, operate.
>
>> Early permanent magnets were known to loose strength with time.

It is not the same: Class D amplifiers feed the voice coil,
and the old loudspeaker replaced the permanent magnet with
the filter choke. There was a separate voice coil fed from the
audio power amplifier tube.

--

-TV

On 7/5/2021 2:34 AM, Tauno Voipio wrote:
> On 3.7.2021 06:15 AM, Don Y wrote:
>> On 7/2/2021 2:20 PM, bilou wrote:
>>> On 27/06/2021 08:11, boB wrote:
>>>> These are great references and books.
>>>>
>>>> The more, the better !
>>>>
>>>> Thanks Don !
>>>>
>>> +1 Thanks
>>> It reminded me of early loudspeakers where the electromagnet
>>> was cleverly used as a filter choke.
>>
>> That's how many (low cost) Class D designs, today, operate.
>>
>>> Early permanent magnets were known to loose strength with time.
>
> It is not the same: Class D amplifiers feed the voice coil,
> and the old loudspeaker replaced the permanent magnet with
> the filter choke. There was a separate voice coil fed from the
> audio power amplifier tube.

Did you miss the point: "...was cleverly used as a filter choke"?

On 5.7.21 12.43, Don Y wrote:
> On 7/5/2021 2:34 AM, Tauno Voipio wrote:
>> On 3.7.2021 06:15 AM, Don Y wrote:
>>> On 7/2/2021 2:20 PM, bilou wrote:
>>>> On 27/06/2021 08:11, boB wrote:
>>>>> These are great references and books.
>>>>>
>>>>> The more, the better !
>>>>>
>>>>> Thanks Don !
>>>>>
>>>> +1 Thanks
>>>> It reminded me of early loudspeakers where the electromagnet
>>>> was cleverly used as a filter choke.
>>>
>>> That's how many (low cost) Class D designs, today, operate.
>>>
>>>> Early permanent magnets were known to loose strength with time.
>>
>> It is not the same: Class D amplifiers feed the voice coil,
>> and the old loudspeaker replaced the permanent magnet with
>> the filter choke. There was a separate voice coil fed from the
>> audio power amplifier tube.
>
> Did you miss the point:  "...was cleverly used as a filter choke"?

The filtering was for the plate (anode) voltage supply, not
for the signal, as in Class D amplifiers.

--

-TV

On 7/5/2021 7:43 AM, Tauno Voipio wrote:
> On 5.7.21 12.43, Don Y wrote:
>> On 7/5/2021 2:34 AM, Tauno Voipio wrote:
>>> On 3.7.2021 06:15 AM, Don Y wrote:
>>>> On 7/2/2021 2:20 PM, bilou wrote:
>>>>> On 27/06/2021 08:11, boB wrote:
>>>>>> These are great references and books.
>>>>>>
>>>>>> The more, the better !
>>>>>>
>>>>>> Thanks Don !
>>>>>>
>>>>> +1 Thanks
>>>>> It reminded me of early loudspeakers where the electromagnet
>>>>> was cleverly used as a filter choke.
>>>>
>>>> That's how many (low cost) Class D designs, today, operate.
>>>>
>>>>> Early permanent magnets were known to loose strength with time.
>>>
>>> It is not the same: Class D amplifiers feed the voice coil,
>>> and the old loudspeaker replaced the permanent magnet with
>>> the filter choke. There was a separate voice coil fed from the
>>> audio power amplifier tube.
>>
>> Did you miss the point: "...was cleverly used as a filter choke"?
>
> The filtering was for the plate (anode) voltage supply, not
> for the signal, as in Class D amplifiers.

You've still missed the point. A choke was eliminated!

On 5.7.21 18.48, Don Y wrote:
> On 7/5/2021 7:43 AM, Tauno Voipio wrote:
>> On 5.7.21 12.43, Don Y wrote:
>>> On 7/5/2021 2:34 AM, Tauno Voipio wrote:
>>>> On 3.7.2021 06:15 AM, Don Y wrote:
>>>>> On 7/2/2021 2:20 PM, bilou wrote:
>>>>>> On 27/06/2021 08:11, boB wrote:
>>>>>>> These are great references and books.
>>>>>>>
>>>>>>> The more, the better !
>>>>>>>
>>>>>>> Thanks Don !
>>>>>>>
>>>>>> +1 Thanks
>>>>>> It reminded me of early loudspeakers where the electromagnet
>>>>>> was cleverly used as a filter choke.
>>>>>
>>>>> That's how many (low cost) Class D designs, today, operate.
>>>>>
>>>>>> Early permanent magnets were known to loose strength with time.
>>>>
>>>> It is not the same: Class D amplifiers feed the voice coil,
>>>> and the old loudspeaker replaced the permanent magnet with
>>>> the filter choke. There was a separate voice coil fed from the
>>>> audio power amplifier tube.
>>>
>>> Did you miss the point:  "...was cleverly used as a filter choke"?
>>
>> The filtering was for the plate (anode) voltage supply, not
>> for the signal, as in Class D amplifiers.
>
> You've still missed the point.  A choke was eliminated!
>

Correct, also, a permanent magnet was eliminated, but the choke
has a different function from Class D output filtering.

--

-TV