Driver to drive?

[Phil Hobbs]

On 02/21/2018 04:53 PM, Jim Thompson wrote:

On Wed, 21 Feb 2018 15:51:55 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 02/21/2018 01:39 PM, Tom Del Rosso wrote:
pcdhobbs@gmail.com wrote:
Have you checked the operating voltage across the lamps?

+1.

What do you consider high? I've never seen more than 14.5 volts in a
car.

Or do you mean the bulbs can somehow see more than the main bus?



Right. But sometimes there's a blown alternator diode or a too-wimpy
alternator *cough* 2000s Fords *cough* and the battery is chronically
undercharged.

Cheers

Phil Hobbs

I kissed off buying Ford products in 1977... nevermore.

...Jim Thompson

They're pretty good at the moment--I've bought two in the last 18 months
and couldn't be happier with them.

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
https://hobbs-eo.com

 

[Phil Hobbs]

On 02/22/2018 01:54 AM, Steve Wilson wrote:

Steve Wilson <no@spam.com> wrote:

Steve Wilson <no@spam.com> wrote:
Another aspect of op amps and linear regulators is the ouput impedance.
It often rises with frequency, giving an inductive characteristic. There
is a paper by Erroil H. Dietz, Senior Technician, National Semiconductor
titled "Understanding and Reducing Noise Voltage on 3-Terminal Voltage
Regulators" that describes this.

The article is very hard to find. Some pdf links have it inverted which
is a pain to have to rotate twice to read it.

I posted it upthread. It's on my website.

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
https://hobbs-eo.com

 

[John Larkin]

On Sun, 18 Feb 2018 13:12:50 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 02/18/2018 08:14 AM, Chris Jones wrote:
On 17/02/2018 07:18, bloggs.fredbloggs.fred@gmail.com wrote:
On Friday, February 16, 2018 at 12:51:24 PM UTC-5, John Larkin wrote:
On Fri, 16 Feb 2018 08:57:05 -0800 (PST),
bloggs.fredbloggs.fred@gmail.com wrote:

On Thursday, February 15, 2018 at 8:32:35 PM UTC-5, John Larkin wrote:
LM317's like some ESR in their output capacitors. I don't want any
electrolytic or tantalum caps in my new thing, just ceramics, and the
sim sure rings:

https://www.dropbox.com/s/11b3w42nsvpliki/317_nocomp.jpg?raw=1

But this fixes it:

https://www.dropbox.com/s/9q80heyfbwh5frp/317_comp.jpg?raw=1

This ain't rocket science, but I haven't seen it done before.

317 needs no such ESR compensation.

The data sheet says it does.

The ringing looks suspiciously like excitation of the SRF of an
output capacitor.

The frequency is low, and is different on the rising and falling edges
of the load current pulse. It's the chip pseudo-inductance resonating,
not the cap's ESL. If the ringing were local to the caps, my damping
on ADJ wouldn't fix that.

Cap series L makes a different waveform than paralleled inductance.


Did your model give it any ESL? And your solution merely reduces the
shunt resistance by a factor of 20x which probably has more to do
with damping than anything else.

With a big cap from ADJ to ground, it rings badly, too. It has to be
the *right* capacitor to damp the ringing.

I tried this with two different LM317 models; the ringing is somewhat
different (the LT317 is better), but the damping idea is the same.

It's amazing that LT ever made a 317. I think they did that early on,
when they needed some revenue. They want $4 for it! I'm paying less
than a tenth of that for TI.

I doubt you're going to see this energetic resonance on anything other
than the LT part.


I doubted it too, but found out the hard way when:
my 337's all oscillated, and
the 317s rang so badly that the oscillation ripple on the positive rails
was even bigger than on the negative rails.

The 317s wouldn't oscillate by themselves, but they would ring like a
bell even after I cured the 337's of oscillation.

I had to scratch off a lot of solder mask and tack on many tantalums to
cure my boards. Quite embarassing.


Check out the Erroll Dietz article I posted upthread.

He used three values of Cadj, 0, 10u, and 1000u. He didn't try
anything like 22nF. I'm sort of surprised that nobody seems to have
tried that, or at least publicized it.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[John Larkin]

On Thu, 22 Feb 2018 09:46:37 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 02/22/2018 09:39 AM, John Larkin wrote:
On 22 Feb 2018 05:51:34 -0800, Winfield Hill
hill@rowland.harvard.edu> wrote:

John Larkin wrote...

On 21 Feb 2018 05:51:58 -0800, Winfield Hill
hill@rowland.harvard.edu> wrote:

tabbypurr@gmail.com wrote...

I'm looking at putting together something similar to a Class AB/B
audio amp, but it will be driven outside its linear range ...
time for output devices to unsaturate ...
Keeping distortion low matters here.

JL has mentioned the issue of feedback integrator windup.
I'd say two aspects can be significant to success.
1) Create a circuit that's linear without feedback,
use minimum feedback, without internal integrators.
2) Make the circuit very fast, faster than needed.

My AMP-70 power amplifier design is an example. The
configuration is intrinsically both linear and fast.
https://www.dropbox.com/sh/an6lcx7y3e3o8zm/AACUoCLGKDOkusNcJnUlcGc2a?dl=0

My circuit was inspired by the Tektronix PG-508 50MHz
function-generator output stage, read my AoE writeup.

The signal pickoff connector J2 is interesting. When I do a high-ratio
scope pickoff on a serious HV pulser, I tend to see a little baseline
noise, probably ground loops. You seem to have the scope grounded
through a 4.7 ohm resistor, which makes up part of the 50 ohm source
impedance. Is that what's going on? Does it improve the pickoff?

I don't like forcing the scope ground to match the noisy
instrument ground, so I isolate it a bit. But I'm not
sure what's going on in the drawing, I'll have to check.

Seems like the 4.7 ohm resistor could increase the noise that the
scope sees, by not forcing the scope ground to be the amp ground.

Low frequency ground loops cause magnetic pickup in both shield and
centre conductor. Grounding the shield shorts that out to some degree,
turning part of the pickup into differential mode.

Likely that the big amp is grounded somewhere, and the scope is
plugged into a grounded outlet somewhere else. The grounds eventually
get together, but usually with lots of HF noise and lots of
microhenries. A short coax hard connected to instrument ground on both
ends can short out that ground inductance and reduce displayed noise.
Sometimes a common-mode ferrite helps. A true isolated-input scope is
great here.

Ground loops at 60 Hz have milliohm impedances, so that 4.7 ohm resistor
looks pretty much like an open circuit to them.

Cheers

Phil Hobbs

--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[Joerg]

On 2018-02-21 09:30, John Larkin wrote:
> On Wed, 21 Feb 2018 12:18:12 -0500, Ingvald44 <noone@nowhere.com>

[...]

A series impedance is not likely to work very well.


Just try it out. It could result in noticeable 120Hz optical ripple but
for those 2mins of a morning pee trip that might be acceptable.

I was not so lucky. A dimmer that ran 2 lamps that I had replaced
with LEDs took out both LED replacements. I replaced the dimmer with
a standard switch. Don't like dimmers anyway. Have had a couple that
were very noisy in the HF radio band.

I just installed a 5-light fixture in another bathroom, and used
dimmable LEDs, with the old dimmer. Works file. Every time I've used
dimmable LEDs with an old cheap triac dimmer, it's worked fine.

I do buy the better LED lamps, like the Philips.

I had the same experience so far but with he cheaper lamps from Costco.
AFAIR it the Feit brand. Radio noise like Ingvald set is a problem
though since I like to listen to AM and shortwave.

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Les Cargill]

tabbypurr@gmail.com wrote:

On Thursday, 22 February 2018 03:23:59 UTC, Les Cargill wrote:
tabbypurr wrote:

I'm looking at putting together something similar to a Class AB/B
audio amp, but it will be driven outside its linear range into
saturation a lot of the time. That's all well & good but for one
thing: wrapping nfb round saturating outputs doesn't work too
well as it takes time for output devices to unsaturate, and the
nfb effectively overreacts, adding distortion. Keeping distortion
low matters here. What tips would you recommend to keep unwanted
distortion minimised?


thanks, NT


Uhhhh.... headroom?

Maybe you've not read through the thread. That wouldn't do what's
required.

I don't know why keeping it off the rails isn't inherently better than
worrying about how it interacts with the rails to begin with.



--
Les Cargill

 

On Thursday, 22 February 2018 15:50:25 UTC, Les Cargill wrote:

tabbypurr wrote:
On Thursday, 22 February 2018 03:23:59 UTC, Les Cargill wrote:
tabbypurr wrote:

I'm looking at putting together something similar to a Class AB/B
audio amp, but it will be driven outside its linear range into
saturation a lot of the time. That's all well & good but for one
thing: wrapping nfb round saturating outputs doesn't work too
well as it takes time for output devices to unsaturate, and the
nfb effectively overreacts, adding distortion. Keeping distortion
low matters here. What tips would you recommend to keep unwanted
distortion minimised?


thanks, NT


Uhhhh.... headroom?

Maybe you've not read through the thread. That wouldn't do what's
required.


I don't know why keeping it off the rails isn't inherently better than
worrying about how it interacts with the rails to begin with.

Once again the required behaviour is that it rails. An amp that doesn't is no use at all.


NT

 

[bitrex]

On 02/21/2018 10:46 PM, Les Cargill wrote:

bitrex wrote:
On 02/20/2018 08:44 PM, krw@notreal.com wrote:
On Tue, 20 Feb 2018 20:31:56 -0500, bitrex
bitrex@de.lete.earthlink.net> wrote:

On 02/13/2018 10:21 PM, krw@notreal.com wrote:
On Tue, 13 Feb 2018 19:23:23 -0500, bitrex
bitrex@de.lete.earthlink.net> wrote:

On 02/13/2018 07:11 PM, krw@notreal.com wrote:
On Tue, 13 Feb 2018 18:34:34 -0500, bitrex
bitrex@de.lete.earthlink.net> wrote:

On 02/13/2018 06:08 PM, krw@notreal.com wrote:
On Sun, 11 Feb 2018 19:01:06 -0600, Les Cargill
lcargill99@comcast.com> wrote:

John Larkin wrote:
On Sun, 11 Feb 2018 16:45:33 -0500, bitrex
bitrex@de.lete.earthlink.net> wrote:

On 02/11/2018 11:54 AM, John Larkin wrote:

https://www.amazon.com/Brotopia-Breaking-Boys-Silicon-Valley/dp/0735213534/ref=sr_1_1?ie=UTF8&qid=1518366993&sr=8-1&keywords=brotopia




    From the NYT review:

What happened in the 1960s and 1970s was that the industry was
exploding and was starved for talent. There just weren’t
enough
people to do the jobs in computing. So they hired these two
psychologists, William Cannon and Dallis Perry, to come up
with a
personality test to screen for good programmers.

Those men decided, in screening about 1,200 men and 200 women,
that good programmers don’t like people — that they have a
complete disinterest in people. These tests were widely
influential and used at various companies for decades.

Most qualities that make a "good programmer" in 2018 have
little to
do with how ingenious or clever you can make the stuff you type
into the box; compilers are very good at this point, CPU
horsepower
is plentiful and premature optimization is the root of all
evil.
It's not easy to write high-performance code but it takes
concerted
effort to write truly poor performing code in most languages.

The most valuable skills probably have to do with a) is your
software based on solid design principles b) how well you can
justify that design/explain your reasoning to others and c) how
easily someone can come in fresh and read your documentation
and
understand the principles of the design. Which if you have no
interest in people and little experience interacting with them
socially is going to be a tough row to hoe.

There will always be a place for the seriously schizoid
hotshots,
e.g. physics code for games needs to eek out every bit of
performance. A physics engine coder might be insulted if you
sullied his labor with anything as mundane as _gameplay_.

Also the problem with being totally disinterested in people
is that
you usually end up thinking you're a lot better than you
actually
are, without any metric to judge your performance how can you
semi-objectively judge.

That review also names a recently-me-too-fallen individual
that
we once did battle with, but I'm not allowed to make any
disparaging remarks about that.

I am continually amazed by the aggressive and toxic Silicon
Valley culture... which has spread into the worldwide
semiconductor industry.

Software used to be fun and novel but then a lot of the
industry
got lame and cynical, like hey let's build a grocery store
list app
for a phone with Bluetooth integration, sell that shit for
$2.99 on
the app store and hope to get bought out by the Big G for
$50 mil
in 14 months.

I think a lotta women bailed out on that scene because "on
average"
they don't value the bignum bills as highly vs. not getting
your
soul crushed to get 'em. Who can blame 'em, I don't. Seems like
most of the "angel" VC funders in the Valley aren't even tech
educated people anymore they're like MBAs and pundits and
famous
bloggers and various Wall Street investment bank weenies
after some
fast bucks



I'm reading "Coders at Work", which is a bunch of interviews
with
famous programmers. What's impressive is how ad-hoc they are,
with
no obvious systematic approaches, sometimes bottom-up, sometimes
top-down; they just sort of do it.


Most people who have done something noteworthy enough to be
interviewed probably didn't have a lot of examples to work from.

Top-down/bottom up is a legit thing to mix up, tho. Start
with the risk items.

Or the unknowns.

Many of them have no formal, or
informal, training in CS or EE or anything. I doubt that many
know
what a state machine is.


Unsurprising. Software people are very often blind to
determinism in
general.

FSM are not a widely understood technique in software.
God only knows why. Even the people who know about them
often think they are always equivalent to regular expressions.

I naturally code that way but when I've shown my code to "real
programmers", they say "that's neat"!  To me, it's the obvious
way to
get across the street - one step at a time (with some checks
along the
way).

It's not that FSMs aren't a useful design pattern for some
problems,
it's just that the software world has moved on to things like OOP,
functional, and generic programming which are more scalable,
extensible,
and abstract

...even where not appropriate.


Nowadays on large projects the most "appropriate" design pattern
is most
often one that generates a codebase 20 or 30 people can work with
simultaneously and not influence each other too much.  You can't have
everyone involved in a project mucking with the state diagrams and
making changes that break other people's shit, so you have to run
modifications thru some master planner guy, which is a bottleneck and
wastes time. It's too "top down." Doesn't scale well.

In a large project like that, programmers shouldn't be making changes
to *ANY* state machines.  That's the what the architect(s) do.  The
programmers implement, they don't design.  Chip designers don't change
the architecture of a processor, either.  They implement the
architect's design.  That's probably why there is so much shit
software out there.  Too many cooks.


That's called "waterfall design" and has been passe in the software
world for I'd guess 30 years or so. It's brittle, inflexible, too
"top-down", there is no one "architect" or small group of architects
who
have a complete God's-eye picture of every single "state" or
function or
branch of code in a 100 million-line codebase.

So has defect-free software.  There is a reason Win* is such shit.

Processor design is a different animal it takes years and years to
bring
a new architecture from concept to finalized design, the software world
is working under much tighter deadlines and customers _expect_ major
changes to be possible for most of the development cycle.

No, it's exactly the same thing.  One group believes in the quality of
their work.

Giving a client this "the design is finalized and being implemented
according to God's plan by the code monkeys and it cannot be touched"
stuff would be a way to find yourself rapidly out of business

So you think the race to the bottom is a good thing.  I could have
guessed that.


There's a lot of lousy code out there, but there's also more great
code out there than there's ever been in history. Well-designed and
implemented software using "modern" practices is not at all hard to
find. Flawed hardware designed top-down is not at all hard to find,
e.g. Spectre, Meltdown.


Spectre/Meltdown happened because Intel ended up on one end of a
tradeoff. They favored performance over security.

Windows isn't shitty because of the techniques used to develop modern
software, it's mostly because it is and always has been a slave to the
past and backwards compatibility. It's always needed a ground-up
rewrite since about 1990 which it never got.


Windows is like it is because Microsoft only hired fresh-outs and
worked 'em like rented mules.

All things considered - *it's not that bad*. It's slow coding to the
Win32 interface, but it's not horrible.

I remember watching a 133 MHz PC running BeOS display 32 full-motion
videos in windows on its desktop while you could simultaneously edit a
document in the word processor with no hiccups or lag at all.


But you couldn't buy a BeOS box at Best Buy ( or Bob's Computer Store
before that ).

Unfortunately for most of its history x86 wasn't particularly amenable
to fast virtualization, a sleek new OS sold in stores in the late 1990s
which could also run the majority of legacy DOS and Windows software
with little performance hit could have been a contender.

Once OS/2, etc. were gone and Microsoft had the market locked down by
the early 2000s Intel and AMD got crackin' on the hardware
virtualization support like gangbusters, interesting that.

 

[John Robertson]

On 2018/02/20 5:22 PM, oldschool@tubes.com wrote:

On Tue, 20 Feb 2018 11:35:51 -0800, John Robertson <spam@flippers.com
wrote:

On 2018/02/20 7:23 AM, oldschool@tubes.com wrote:
Sylvania Silverstar headlights are said to be "great". But I wonder if
that was said by users, or by the sellers. I bought a pair of them on
ebay. It was cheaper than in the stores, where a pair of them sell for
$30 and up.

I bought them because my mid 90s Plymouth minivan has poor headlight
brightness. All of them do and there are a lot of complaints about that
make/model on the web. Part of my poor visibility was due to cloudy
lenses and headlight adjustment. I cleaned the lenses and adjusted them.
That was a big improvement, but I was still not satisfied.

I bought these bulbs last May on ebay. They were a slight improvement.
But not what was advertised. They are also not as blue in color as
stated. They arrived in a sealed package, and new. For the amount of
improvement I was disappointed, but I bought them and every bit of extra
brightness was a plus, since I do a lot of night driving and often on
rural roads.

Anyhow, it's about 9 months since I installed them, and last week, one
bulb burned out. I should mention that I dont drive all that much. I
contacted Sylvania and they said they have a one year warranty on those
bulbs, but need proof of purchase. I said No problem, I have the
confirmation email from the ebay seller, which I can forward to them.

I was told that they do not warranty items purchased on ebay or other
online auctions. Only from actual stores such as auto parts stores,
Walmart, etc.

I made sure to tell them exactly how I felt about their warranty (or
lack of one). And let them know that I will not buy anything from their
company anymore.

What gets me, is that I can buy items sold by legitimate brick and
mortar stores on ebay. For example, Autozone, Carquest, and so on....
All of them sell on ebay, and there are National auto parts sellers who
have actual stores, but also sell on ebay.

I am not impressed in the least by these bulbs, and wont buy them again.
I now have a color imbalance on my headlights, because I have the one
remaining Silverstar bulb on one side and a standard halogen on the
other side. I suppose I'll have to just go back to the standard bulbs on
both sides. I did check on LED replacements, but I was shocked when I
found they cost $200 and up....



Buying stuff on eBay is fraught with problems as a large percentage of
the products are counterfeit made in China or wherever. You do realize
that what you buy from Amazon, eBay, etc. is totally unregulated and is
often unsafe. I've recently bought some monitors on Amazon and the
external power supplies were a joke. the three wire female cord ended in
a two prong plug! No marking on the supplies or power cord/plug for any
electrical safety - UL, CSA or cUL so we tossed the original supplies
and installed good products that meet CSA/UL standards purchased from a
reputable dealer who stands behind his product.

The manufacturer is quite correct in refusing to honour a warranty for a
most likely (99.999%) counterfeit item. There is a reason the authentic
ones cost more than the crap copies! Packaging means nothing, it is easy
to duplicate that. Might even have been made by the same factory, but
didn't meet Sylvanias specs so they sell them on eBay to get rid of
them. If you think that doesn't happen you should spend some time
researching Counterfeit Products online. From Capacitors, ICs,
transistors, cameras, phones,...to your headlight bulb saving money will
usually cost you in the end.

John

I highly doubt this bulb is a counterfeit. The packaging is exactly like
in a store. Even had the anti-theft magnetic strip below the bulbs.

I have gotten a few bad items on ebay, and most have been covered by the
seller or ebay, if I find the problem within a short time after getting
the item. I have been pretty well satisfied with most of the stuff I
buy. which includes a lot of electronic connectors and some other parts.
Capacitors on ebay are always high priced it seems, so I avoid them.
(mostly referring to caps for old tube gear).

....

I guess it depends on the item, and there are going to be some bad items
once and awhile. But I usually get the price refunded if it's bad. These
bulbs are an exception, because they exceeded the sellers
refund/replacement period.

Then again, I had a brick and mortar auto parts store refuse to give me
a replacement part, when their rebuilt part failed about 2 days beyond
the warranty. I quit shopping there after that....

I am surprised you are not willing to consider that the bulbs are likely
counterfeit, don't you do any research?

https://www.powerbulbs.com/ca/blog/2014/11/how-can-i-tell-if-my-xenon-bulbs-are-real-or-fake

As for the brick and motor place you stopped buying from, while I agree
some flexibility in warranty extension is reasonable (we do it all the
time), perhaps a chat with the manager might have cleared that up.

John

 

[Phil Hobbs]

On 02/22/2018 10:11 AM, John Larkin wrote:

On Sun, 18 Feb 2018 13:12:50 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 02/18/2018 08:14 AM, Chris Jones wrote:
On 17/02/2018 07:18, bloggs.fredbloggs.fred@gmail.com wrote:
On Friday, February 16, 2018 at 12:51:24 PM UTC-5, John Larkin wrote:
On Fri, 16 Feb 2018 08:57:05 -0800 (PST),
bloggs.fredbloggs.fred@gmail.com wrote:

On Thursday, February 15, 2018 at 8:32:35 PM UTC-5, John Larkin wrote:
LM317's like some ESR in their output capacitors. I don't want any
electrolytic or tantalum caps in my new thing, just ceramics, and the
sim sure rings:

https://www.dropbox.com/s/11b3w42nsvpliki/317_nocomp.jpg?raw=1

But this fixes it:

https://www.dropbox.com/s/9q80heyfbwh5frp/317_comp.jpg?raw=1

This ain't rocket science, but I haven't seen it done before.

317 needs no such ESR compensation.

The data sheet says it does.

The ringing looks suspiciously like excitation of the SRF of an
output capacitor.

The frequency is low, and is different on the rising and falling edges
of the load current pulse. It's the chip pseudo-inductance resonating,
not the cap's ESL. If the ringing were local to the caps, my damping
on ADJ wouldn't fix that.

Cap series L makes a different waveform than paralleled inductance.


Did your model give it any ESL? And your solution merely reduces the
shunt resistance by a factor of 20x which probably has more to do
with damping than anything else.

With a big cap from ADJ to ground, it rings badly, too. It has to be
the *right* capacitor to damp the ringing.

I tried this with two different LM317 models; the ringing is somewhat
different (the LT317 is better), but the damping idea is the same.

It's amazing that LT ever made a 317. I think they did that early on,
when they needed some revenue. They want $4 for it! I'm paying less
than a tenth of that for TI.

I doubt you're going to see this energetic resonance on anything other
than the LT part.


I doubted it too, but found out the hard way when:
my 337's all oscillated, and
the 317s rang so badly that the oscillation ripple on the positive rails
was even bigger than on the negative rails.

The 317s wouldn't oscillate by themselves, but they would ring like a
bell even after I cured the 337's of oscillation.

I had to scratch off a lot of solder mask and tack on many tantalums to
cure my boards. Quite embarassing.


Check out the Erroll Dietz article I posted upthread.

He used three values of Cadj, 0, 10u, and 1000u. He didn't try
anything like 22nF. I'm sort of surprised that nobody seems to have
tried that, or at least publicized it.

I expect that the required value will be pretty vendor-dependent. The
Diodes TLV431 is very C-stable, but the TI one isn't, and the On Semi
one is horrendous.

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
https://hobbs-eo.com

 

[lunologist]

On 02/21/2018 11:12 AM, oldschool@tubes.com wrote:

On Wed, 21 Feb 2018 13:39:30 -0500, "Tom Del Rosso"
fizzbintuesday@that-google-mail-domain.com> wrote:

pcdhobbs@gmail.com wrote:
Have you checked the operating voltage across the lamps?

+1.

What do you consider high? I've never seen more than 14.5 volts in a
car.

Or do you mean the bulbs can somehow see more than the main bus?



These bulbs just connect to the 12volt source. There is a relay between
the light switch, and of course fuses.

My 2001 Dodge truck had _no_ relays until I added them. At the same
time, I put in heavier wiring and swapped the mediocre stock headlights
for vastly better dual-bulb versions that Dodge put on the "Sport" model
truck.

The headlight upgrade was motivated by Daniel Stern, who was posting on
the Dodge truck group for a while. I bought the relays and some adapters
from Stern. He was also recommending GE Nighthawk bulbs at the time, and
told me my Silverstars were a poor choice because of the blue glass. I
couldn't find Nighthawks and bought something else, which has been going
for 13+ years now since the Silverstar duds were removed.

You might find something useful at
<http://www.danielsternlighting.com/home.html>

He knows his stuff, appears to be a Mopar fan, and might know what's
feasible for a mid 90s Plymouth minivan.

 

[Winfield Hill]

tabbypurr@gmail.com wrote...

Once again the required behaviour is that it rails.
An amp that doesn't is no use at all.

CFB opamps come out of saturated condition very rapidly.


--
Thanks,
- Win

 

[Jim Thompson]

On Thu, 22 Feb 2018 09:47:59 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 02/21/2018 04:53 PM, Jim Thompson wrote:
On Wed, 21 Feb 2018 15:51:55 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 02/21/2018 01:39 PM, Tom Del Rosso wrote:
pcdhobbs@gmail.com wrote:
Have you checked the operating voltage across the lamps?

+1.

What do you consider high? I've never seen more than 14.5 volts in a
car.

Or do you mean the bulbs can somehow see more than the main bus?



Right. But sometimes there's a blown alternator diode or a too-wimpy
alternator *cough* 2000s Fords *cough* and the battery is chronically
undercharged.

Cheers

Phil Hobbs

I kissed off buying Ford products in 1977... nevermore.

...Jim Thompson

They're pretty good at the moment--I've bought two in the last 18 months
and couldn't be happier with them.

Cheers

Phil Hobbs

I bought my second Q45 _13_years_ago_ and couldn't be happier... I
really like the team-up of a honkin' V8 and _real_ leather ;-)

Wanna drag ?>:-}

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

It's what you learn, after you know it all, that counts.

 

[Jim Thompson]

On 22 Feb 2018 09:37:06 -0800, Winfield Hill
<hill@rowland.harvard.edu> wrote:

tabbypurr@gmail.com wrote...

Once again the required behaviour is that it rails.
An amp that doesn't is no use at all.

CFB opamps come out of saturated condition very rapidly.

Yep. I've become a fan just from writing Spice models for Apex
(Tucson).

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

It's what you learn, after you know it all, that counts.

 

[Steve Wilson]

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

On 02/22/2018 01:54 AM, Steve Wilson wrote:
Steve Wilson <no@spam.com> wrote:

Steve Wilson <no@spam.com> wrote:
Another aspect of op amps and linear regulators is the ouput
impedance. It often rises with frequency, giving an inductive
characteristic. There is a paper by Erroil H. Dietz, Senior
Technician, National Semiconductor titled "Understanding and Reducing
Noise Voltage on 3-Terminal Voltage Regulators" that describes this.

The article is very hard to find. Some pdf links have it inverted
which is a pain to have to rotate twice to read it.

I posted it upthread. It's on my website.

Cheers

Phil Hobbs

So you're the guy who posts upside-down pdfs!

Here it is, right-side up, OCR'd and reduced from 3,494,831 to 1,652,242
bytes:

https://silvercell.000webhostapp.com/pdfs/dietz.pdf

Please replace the one on your site so people can use it

 

On Thursday, 22 February 2018 17:41:34 UTC, Jim Thompson wrote:

On 22 Feb 2018 09:37:06 -0800, Winfield Hill
hill@rowland.harvard.edu> wrote:
tabbypurr wrote...

Once again the required behaviour is that it rails.
An amp that doesn't is no use at all.

CFB opamps come out of saturated condition very rapidly.

Yep. I've become a fan just from writing Spice models for Apex
(Tucson).

...Jim Thompson

cheers you 2, could be useful to know


NT

 

[George Herold]

On Thursday, February 22, 2018 at 2:09:28 PM UTC-5, Steve Wilson wrote:

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

On 02/22/2018 01:54 AM, Steve Wilson wrote:
Steve Wilson <no@spam.com> wrote:

Steve Wilson <no@spam.com> wrote:
Another aspect of op amps and linear regulators is the ouput
impedance. It often rises with frequency, giving an inductive
characteristic. There is a paper by Erroil H. Dietz, Senior
Technician, National Semiconductor titled "Understanding and Reducing
Noise Voltage on 3-Terminal Voltage Regulators" that describes this.

The article is very hard to find. Some pdf links have it inverted
which is a pain to have to rotate twice to read it.

I posted it upthread. It's on my website.

Cheers

Phil Hobbs

So you're the guy who posts upside-down pdfs!

No you're just in the wrong hemisphere. :^)
When I right click on a pdf I get the option to rotate CCW or CW,
which is what I did.

Here it is, right-side up, OCR'd and reduced from 3,494,831 to 1,652,242
bytes:

https://silvercell.000webhostapp.com/pdfs/dietz.pdf

Please replace the one on your site so people can use it

 

[Phil Hobbs]

On 02/22/2018 02:09 PM, Steve Wilson wrote:

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

On 02/22/2018 01:54 AM, Steve Wilson wrote:
Steve Wilson <no@spam.com> wrote:

Steve Wilson <no@spam.com> wrote:
Another aspect of op amps and linear regulators is the ouput
impedance. It often rises with frequency, giving an inductive
characteristic. There is a paper by Erroil H. Dietz, Senior
Technician, National Semiconductor titled "Understanding and Reducing
Noise Voltage on 3-Terminal Voltage Regulators" that describes this.

The article is very hard to find. Some pdf links have it inverted
which is a pain to have to rotate twice to read it.

I posted it upthread. It's on my website.

Cheers

Phil Hobbs

So you're the guy who posts upside-down pdfs!

Here it is, right-side up, OCR'd and reduced from 3,494,831 to 1,652,242
bytes:

https://silvercell.000webhostapp.com/pdfs/dietz.pdf

Please replace the one on your site so people can use it

Thanks!

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
https://hobbs-eo.com

 

[Robert Baer]

...since at least Eagle ver 5 if not earlier.
Did you know that the produced Gerbers in cases DO NOT reflect what
you see on the screen?

Now, someone pointed out that Gerbers are vector.
True,but that has noting to do with fonts or anything else except the
Gerber strokes as a collection, are supposed to represent the original:
a PCB pad, a logo scribble, Cyrilic font, Arabic font, or any other font
AS CREATED AND SEEN ON THE SCREEN.

MOST irritating is that any text in proportional font on the screen
is rendered as their vector font.

Next, that the (vector font) characters look stunted; most especially
the "R" looks as if its legs were sawed off.
The screen version is elegant; you will NOT get what you see.

Also, some of the vector font symbols are totally trashed, for
example the Registered Trademark symbol ÂŽ looks like a rotated "L" and
there is no replacement unless one wishes to construct one using a
circle and (at least on the screen) a "R"; result has the inelegant and
trashy looking vector font "R".

Such junk is not seen unless one uses an independent Gerber viewer.
**

Now, on occasion, a layer may "inherit" AND/OR "ghost" something from
another layer, and move the position as well.
In one particular case, (so to speak) without asking, a text got
solder-masked (the "ghost" because i never saw it since i do not bother
turning that layer on). And that solder mask was (o be polite)
mis-positioned.
At the same time, a placed circle (layer 1 Top, made for no hole in
center) got duplicated in layer 30 Bstop and position was changed (here
is the "ghosting").
Furthermore, that layer 1 circle got duplicated in layer 290 Tstop
and the position was ALSO changed.
The result was a total mess
**
SO, VERY carefully review ALL layers on the screen at minimum and fix
as needed.
Use a Gerber viewer to double-check the results, especially fonts.

Naturally, because a rich owner of Eagle has decided to also be
greedy, expect these problems WILL NEVER be fixed.

 

On Thursday, 25 January 2018 09:32:12 UTC, Nick Cat wrote:

What would be a good multi-stage charger for 12-15Ah 24v SLAs? I'm in UK. Thanks.

I've been looking again at this one, it never got solved.

Meanwell: the only possible contender is
https://www.tme.eu/gb/details/pb-230-24/chargers/mean-well/
but the charge & float voltages are too high for SLAs, so I think it's no go.

I thought I'd look on ebay & amazon... mixed results, the main question being completely unknown quality from unknown chinese/hk sellers

ÂŁ27.99+0. 4 stage, for SLAs. Sounds good except all the customer reviews are all in Chinglish! I smell a fairly large rodent.
https://www.amazon.co.uk/dp/B0776PZLXN/ref=sspa_dk_detail_3?psc=1&smid=AR43LS1X3DZXK

This looks more interesting:
ÂŁ24.75+0 Anjing 12/24v
https://www.amazon.co.uk/Espeedy-Electric-Battery-Intelligent-Automobile/dp/B0777P6B75/ref=sr_1_12?ie=UTF8&qid=1519333902&sr=8-12&keywords=24v+stage+battery+charger
4 stage charging plus 'pulse auto revive.' No idea if that approach works much, if it does I have a deadun as well I could try it on.
quote...
stopped automatic when charge full,pulse auto revive and maintenance battery ,include 5-stage mode：Idle mode,Constant curren,Constant Voltage,Floating charge mode，Trickle charge mode.
cuts out at 105C!
This product is applicable to the 12V/24V 200 AH lead acid battery ,including GEL,UPS,wet battery and maintenance-free battery.Advanced pulse width modulation (PWM) technology is used to automatically charge batteries through a 4-stage charging cycle
Notice:The 12V input when automatic charging mode,Full electric voltage of 13.8V to 14.3V,about 16V input when manual charging mode,must be artificial monitoring in case of overcharge if manual mode charging,suggest stop charging when the battery beating.

The V, I & % meter would also be a welcome plus, at least if reasonably functional. MBTF is anyone's guess.


Any more ideas or feedback welcome


NT