AoE x-Chapters - 1x.2 Resistors

[Winfield Hill]

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1


--
Thanks,
- Win

 

[Jan Panteltje]

On a sunny day (4 Aug 2019 08:49:18 -0700) it happened Winfield Hill
<winfieldhill@yahoo.com> wrote in <qi6upu02ojg@drn.newsguy.com>:

Winfield Hill wrote...

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

Ooops, perhaps a bad link, try this one:
https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_Draft.pdf?dl=1

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1

Nice, many digipots listed.

 

[Winfield Hill]

Winfield Hill wrote...

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

Ooops, perhaps a bad link, try this one:
https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_Draft.pdf?dl=1

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1

--
Thanks,
- Win

 

[Cursitor Doom]

On Sun, 04 Aug 2019 08:49:18 -0700, Winfield Hill wrote:

Winfield Hill wrote...

Here's another AoE x-Chapters DRAFT section to read and think about.
1x.2 Resistors, takes up aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not yet placed properly,
etc. Comments solicited.

Ooops, perhaps a bad link, try this one:
https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_Draft.pdf?dl=1

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1

First one worked find here.



--
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the Usenet protocol. Reproduction in whole or part through other
protocols, whether for profit or not, is conditional upon a charge of
GBP10.00 per reproduction. Publication in this manner via non-Usenet
protocols constitutes acceptance of this condition.

 

[Winfield Hill]

John Larkin wrote...

On 4 Aug 2019 08:20:02 -0700, Winfield Hill <winfieldhill@yahoo.com
wrote:

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1

Excellent stuff on non-ideal effects and digipots.

If you have time (which I'd guess is unlikely)
you might mention trimpots. They are frowned on
in some circles, but sometimes they are what works.

Yes, use them all the time, adhering to Bob Pease's
suggestion that they not be relied upon for better
than 1% trimming resolution and stability, even the
15-turn ones, IIRC.

What would you advise our readers?


--
Thanks,
- Win

 

[John Larkin]

On 4 Aug 2019 08:20:02 -0700, Winfield Hill <winfieldhill@yahoo.com>
wrote:

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1

Excellent stuff on non-ideal effects and digipots.

If you have time (which I'd guess is unlikely) you might mention
trimpots. They are frowned on in some circles, but sometimes they are
what works.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[John Larkin]

On 4 Aug 2019 11:27:05 -0700, Winfield Hill <winfieldhill@yahoo.com>
wrote:

John Larkin wrote...

On 4 Aug 2019 08:20:02 -0700, Winfield Hill <winfieldhill@yahoo.com
wrote:

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1

Excellent stuff on non-ideal effects and digipots.

If you have time (which I'd guess is unlikely)
you might mention trimpots. They are frowned on
in some circles, but sometimes they are what works.

Yes, use them all the time, adhering to Bob Pease's
suggestion that they not be relied upon for better
than 1% trimming resolution and stability, even the
15-turn ones, IIRC.

What would you advise our readers?

What mostly interests me is using pots to set gain in wideband
DC-coupled circuits, which is difficult to do otherwise. Some pots
have bizarre, high-inductance geometries inside, and some are good to
a couple GHz. But that's kind of niche-y.

We don't use multi-turn pots; they are if anything less settable than
singles. My ROT is that a decent 1-turn pot is settable to about 0.1%
and stable to a few times that. 1% of the pot's range is probably
prudent as a production limit. Dipswitch + pot is extreme but
sometimes the best way to go.

You could also mention r-packs, given all the time you have on your
hands.

The Susumu surface-mount resistors are cheap and really good. The
guaranteed 25 PPM parts are 10 or 20 cents, and measure in the single
digits of tempco.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[John Robertson]

On 2019/08/04 11:27 a.m., Winfield Hill wrote:

John Larkin wrote...

On 4 Aug 2019 08:20:02 -0700, Winfield Hill <winfieldhill@yahoo.com
wrote:

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1

Excellent stuff on non-ideal effects and digipots.

If you have time (which I'd guess is unlikely)
you might mention trimpots. They are frowned on
in some circles, but sometimes they are what works.

Yes, use them all the time, adhering to Bob Pease's
suggestion that they not be relied upon for better
than 1% trimming resolution and stability, even the
15-turn ones, IIRC.

What would you advise our readers?

I liked page "24" "The ever-creative John Larkin needed to find out the
best choice for a 0.33 Ί resistor for a pulse-stress application...."
and then went on to describe how your RUT (Resistor Under Test) treated
poor John's once-of-a-kind test fixture. For shame! (ducking). (I merely
misplace/lose lent equipment for a year (or three) in my shop lab...)

Thanks for this fascinating read on the humble resistor!

John :-#)#

 

On Sunday, 4 August 2019 21:02:37 UTC+1, John S wrote:

Win,
It may be out of scope, but just in case:
Something I came across a long time ago was a degradation mechanism
of spiral cut film power resistors at high common mode voltage.
It appeared that corona discharge was happening at the edges of the
spiral cuts (even though they were protected with some sort of
paint or glaze) causing erosion of the film and early failure.
I don't know whether the film was carbon or metal.

John

 

[John Larkin]

On Sun, 4 Aug 2019 12:07:19 -0700, John Robertson <spam@flippers.com>
wrote:

On 2019/08/04 11:27 a.m., Winfield Hill wrote:
John Larkin wrote...

On 4 Aug 2019 08:20:02 -0700, Winfield Hill <winfieldhill@yahoo.com
wrote:

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1

Excellent stuff on non-ideal effects and digipots.

If you have time (which I'd guess is unlikely)
you might mention trimpots. They are frowned on
in some circles, but sometimes they are what works.

Yes, use them all the time, adhering to Bob Pease's
suggestion that they not be relied upon for better
than 1% trimming resolution and stability, even the
15-turn ones, IIRC.

What would you advise our readers?



I liked page "24" "The ever-creative John Larkin needed to find out the
best choice for a 0.33 ? resistor for a pulse-stress application...."
and then went on to describe how your RUT (Resistor Under Test) treated
poor John's once-of-a-kind test fixture. For shame! (ducking). (I merely
misplace/lose lent equipment for a year (or three) in my shop lab...)

Thanks for this fascinating read on the humble resistor!

John :-#)#

Here's the H+H improvement to the zapper,

https://www.dropbox.com/s/hdson19yrdxu15n/mezz_02.jpg?raw=1

which I should have done from the start. The hogged-out bit in the
corner should have been an adequate warning.




--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[John S]

On 8/4/2019 10:20 AM, Winfield Hill wrote:

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1

Hi, Win -

Immediately below figure 1x39 is the following:
"...and a tempco of ratio of 5 ppm/◦C max."

It reads better to me with only one "of" in the sentence. Personally, I
would leave out the first "of" and make it "...and a tempco ratio of 5
ppm/◦C max."

Just my 2 cents.

John

P.S. Excellent paper!

 

[Phil Hobbs]

On 8/4/19 3:01 PM, John Larkin wrote:

On 4 Aug 2019 11:27:05 -0700, Winfield Hill <winfieldhill@yahoo.com
wrote:

John Larkin wrote...

On 4 Aug 2019 08:20:02 -0700, Winfield Hill
winfieldhill@yahoo.com> wrote:

Here's another AoE x-Chapters DRAFT section to read and think
about. 1x.2 Resistors, takes up aspects of resistors not
discussed in AoE III. This is a draft, with more to add,
figures not yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1



Excellent stuff on non-ideal effects and digipots.

If you have time (which I'd guess is unlikely) you might mention
trimpots. They are frowned on in some circles, but sometimes they
are what works.

Yes, use them all the time, adhering to Bob Pease's suggestion that
they not be relied upon for better than 1% trimming resolution and
stability, even the 15-turn ones, IIRC.

What would you advise our readers?


What mostly interests me is using pots to set gain in wideband
DC-coupled circuits, which is difficult to do otherwise.

Especially if you need low noise. Transconductance-based VCAs are super
noisy at low gains.

Some pots have bizarre, high-inductance geometries inside, and some
are good to a couple GHz. But that's kind of niche-y.

We don't use multi-turn pots; they are if anything less settable
than singles. My ROT is that a decent 1-turn pot is settable to about
0.1% and stable to a few times that. 1% of the pot's range is
probably prudent as a production limit. Dipswitch + pot is extreme
but sometimes the best way to go.

Wirewound pots are a bit like a mechanical DAC--they have a staircase
characteristic with about 500 steps.

You could also mention r-packs, given all the time you have on your
hands.

Especially the use of common-centroid design, e.g. making a 2:1 divider
with a quad pack thin-film resistor wired as (R1 + R4) and (R2 + R3).
That helps with both temperature and resistance gradients.

The Susumu surface-mount resistors are cheap and really good. The
guaranteed 25 PPM parts are 10 or 20 cents, and measure in the
single digits of tempco.

+1.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Phil Hobbs]

On 8/4/19 11:20 AM, Winfield Hill wrote:

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1

Interesting stuff, thanks. D-pots are fairly hard to use well in signal
applications, as you usefully point out.

BTW a 'nicety' is a fine or subtle distinction, not something nice.
(Cf. 'enormity'.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[whit3rd]

On Sunday, August 4, 2019 at 1:23:37 PM UTC-7, jrwal...@gmail.com wrote:

On Sunday, 4 August 2019 21:02:37 UTC+1, John S wrote:

Win,
It may be out of scope, but just in case:
Something I came across a long time ago was a degradation mechanism
of spiral cut film power resistors at high common mode voltage.
It appeared that corona discharge was happening at the edges of the
spiral cuts (even though they were protected with some sort of
paint or glaze) causing erosion of the film and early failure.
I don't know whether the film was carbon or metal.

Any generated ozone attacks carbon film, or even composite,
resistors. HV focus resistors are infamous for failing OPEN, even while dozens
of non-HV similar components survive.

 

[Tom Del Rosso]

Winfield Hill wrote:

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1

Don't forget this chestnut:


On Sun, 19 Jan 2003 12:46:30 -0800,
John Larkin <jjlarkin@highSNIPlandTHIStechPLEASEnology.etc>,
In Newsgroup: sci.electronics.design,
Article: <8s2m2vcp39h4ofvpkjthranc9tqaia246m@4ax.com>,
Entitled: "Don't do this! Just don't!",
Wrote the following:

OK, every once in a while we need to have a trimpot crank in a little
bit of DC offset into an opamp or something, and there are those nice
+-15 or whatever power rails handy. But I see so many presumably
intelligent engineers do something like this:


+15----------+
|
|
10k
|
|
P
100r O <-------- small offset
T
|
|
10k
|
|
-15----------+


This is a *very*bad*idea*. I recent sold a bunch of
amplifier/discriminator boxes because somebody else did this, among
other dumb things.

So quit doing this. Just quit it.

John

====END QUOTE====

 

[Tim Williams]

Fig 1x.29 -- what about capacitance of noninductives?

Depends actually which type, Ayrton-Perry should be fine but bifilar
(shorted at one end) will be awful.

Speaking of Ayrton, she was not only one of the first EEs as such, but one
of if not the first female EE. I don't know if that's footnote-worthy, but
it's not well known I think!

Thin film resistors -- I've heard paranoia about these corroding. Any
insight? (Not AoE-specific, anyone's experience will do.) Maybe was a
legitimate concern, now outdated?

Fig 1x.30 is very useful! It looks visually noisy though; could you get
that formatted as a heatmap, or like, drawing dotted or hashed curves around
the general area of each family?

May be worth a note, Fig 1x.31 -- you can flatten out a messy resistor,
sure, but you're just moving the power dissipation from one resistor to the
other. Fatal for signals with a large RF component!

Do you have any data on TO-220 and other power film resistors, in terms of
capacitance to heatsink, or equivalent circuits? And JL's measured
significant "drool" apparently from induction into the heatsink I think, in
such parts?

So many directions to explore with only so much time to go around, I know.
:-S Looking forward to the finished book!

Tim

--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Design
Website: https://www.seventransistorlabs.com/

"Winfield Hill" <winfieldhill@yahoo.com> wrote in message
news:qi6t3202m4t@drn.newsguy.com...

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1


--
Thanks,
- Win

 

On Sunday, 4 August 2019 16:20:24 UTC+1, Winfield Hill wrote:

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1

a very minor point...

"You often use a high-resistance voltage divider to monitor a high-voltage dc supply,"

do I?

 

[George Herold]

On Sunday, August 4, 2019 at 3:01:45 PM UTC-4, John Larkin wrote:

On 4 Aug 2019 11:27:05 -0700, Winfield Hill <winfieldhill@yahoo.com
wrote:

John Larkin wrote...

On 4 Aug 2019 08:20:02 -0700, Winfield Hill <winfieldhill@yahoo.com
wrote:

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1

Excellent stuff on non-ideal effects and digipots.

If you have time (which I'd guess is unlikely)
you might mention trimpots. They are frowned on
in some circles, but sometimes they are what works.

Yes, use them all the time, adhering to Bob Pease's
suggestion that they not be relied upon for better
than 1% trimming resolution and stability, even the
15-turn ones, IIRC.

What would you advise our readers?


What mostly interests me is using pots to set gain in wideband
DC-coupled circuits, which is difficult to do otherwise. Some pots
have bizarre, high-inductance geometries inside, and some are good to
a couple GHz. But that's kind of niche-y.

We don't use multi-turn pots; they are if anything less settable than
singles. My ROT is that a decent 1-turn pot is settable to about 0.1%
and stable to a few times that. 1% of the pot's range is probably
prudent as a production limit. Dipswitch + pot is extreme but
sometimes the best way to go.
Cermet material? Do you have a favorite brand?

We use a bunch of panel mount pots.. For DC and low freq the Bourns
10 turn pots are nice.

We would also mention Phil H's loaded pot technique. (Which I've only used
once.. but nice to have in your bag-o-tricks.) (You tie a two smaller
resistors from the pot ends to the wiper.. makes a lower value pot with
very fine adjustment.)

You could also mention r-packs, given all the time you have on your
hands.

The Susumu surface-mount resistors are cheap and really good. The
guaranteed 25 PPM parts are 10 or 20 cents, and measure in the single
digits of tempco.
Yeah.

George H.

--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[George Herold]

On Sunday, August 4, 2019 at 11:20:24 AM UTC-4, Winfield Hill wrote:

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1


--
Thanks,
- Win

Thanks Win... really good stuff!

George H.
(is there a capacitor X-chapter?)

 

On Sunday, 4 August 2019 16:20:24 UTC+1, Winfield Hill wrote:

Here's another AoE x-Chapters DRAFT section to
read and think about. 1x.2 Resistors, takes up
aspects of resistors not discussed in AoE III.
This is a draft, with more to add, figures not
yet placed properly, etc. Comments solicited.

https://www.dropbox.com/s/dli62uyuldr7z5q/1x.2_Resistors_DRAFT.pdf?dl=1

Fig 1x.30: I'd suggest adding construction type to the list printed on the graph.
Fig 1x.32, lower graph: scales marked -0.5% and -50%!
Fig 1x.37: if you move the B to above the C it would be clearer

"Its failure mode, like the carbon-film CMA, includes
a low-resistance current surge and a fail-short endpoint."

Some readers may misinterpret that as meaning that it shorts permanently. In fact they can go very low R but recover & resume normal service.

Figure 1x.39 Including social stuff is only going to irk those who don't know you from Adam and have no interest.

Motor driven panel pots were still in mass production in a minority of consumer stereos in the 80s.

Fig 1x.43 lacks any scale markings.

p32 'niceties' - I'm not sure those are niceties according to a dictionary.


NT