Driver to drive?

On Wed, 21 Feb 2018 20:57:38 -0500, bitrex
<bitrex@de.lete.earthlink.net> wrote:

On 02/21/2018 06:44 PM, krw@notreal.com wrote:
On Wed, 21 Feb 2018 09:17:24 -0800 (PST), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

Den onsdag den 21. februar 2018 kl. 17.18.30 UTC+1 skrev John Larkin:
On Wed, 21 Feb 2018 07:12:38 -0500, bitrex
bitrex@de.lete.earthlink.net> wrote:

On 02/20/2018 10:48 PM, John Larkin wrote:
On Tue, 20 Feb 2018 21:40:31 -0500, bitrex
bitrex@de.lete.earthlink.net> wrote:

On 02/20/2018 08:43 PM, Paul Hovnanian P.E. wrote:
Jim Thompson wrote:

https://www.nbcbayarea.com/news/local/Diseased-Streets-472430013.html

If they are smart, they won't wake up the hobos before running the steam
cleaner down the sidewalk.


The news story claims "Over 100!" discarded IV needles found in the
areas they surveyed but you can easily click through all the "red"
streets in the map and see that the tally tops out at barely 50. And
there are big clumps of 7 or 10 needles in some locations.

Pay one or two bums a couple bucks to dump their spent needles in a
couple locations and hey presto you've got yourself a story.

And you have an army of well-paid attorneys, consultants, NGOs,
providers, and city staffers actually soaking up the funding.

We never go downtown. That's for bankers and tourists. Our
neighborhood is green, quiet, clean, and safe.

https://www.dropbox.com/s/kpl55nnziaubq9z/Ohlone_Way_3.jpg?raw=1

I've never seen a needle on Ohlone Way. You might get stuck picking
blackberries.



It's a histrionic "story" crafted to play well with histrionics of all
political persuasions, left or right few Americans can seem to resist a
good "OMG THINK OF THE CHILDREN!" tale.

Meanwhile I'd estimate statistics on the number of children who could be
confirmed to have caught the AIDS or any infectious disease from any
discarded IV needle in SF or any other large city for that matter is
likely pretty close to 0.

The HIV virus is fragile out on its own.

yeh

https://www.poz.com/article/HIV-risk-25382-5829

"the average risk of contracting HIV through sharing a needle one time with an HIV-positive drug user is 0.67 percent"

Feel like playing Russian roulette? Seems hospitals are worried a
bunch about HIV and similar diseases.


Almost like nurses and phlebotomists have to deliberately handle dozens
of dirty needles/sharps a day as part of their job duties

They know what they're doing and, if you ever really seen what goes on
in a hospital, there is a sharps disposal mechanism in almost every
room. They won't come anywhere near you without gloves. Many nurses
_have_ become HIV positive because of their jobs. Whatever you think
(not much, obviously), it is treated very seriously.

 

[Ivan Shmakov]

makolber@yahoo.com writes:
On Tuesday, February 20, 2018 at 4:12:50 PM UTC-5, Ivan Shmakov wrote:

So, we were making some prototypes for Chebyshev passive filters for
the SW range, and found out that most of the time, the resonance
frequencies of the individual LC circuits there are considerably
lower than expected, with the apparent culprit being the inductances
of the custom coils we made, which seem to be much higher (20% to
30%) in the operating range (about 25 MHz) than both the design
values and the values as measured on a 200 kHz RLC meter. (Say,
about 93 nH @ 25.5 MHz vs. 83 nH @ 200 kHz.)

The question is, is it some well-known effect, or am I mistaking
something else for the perceived change in inductance?

(I understand that at higher frequencies the stray capacitance
effectively turns a coil into a parallel LC circuit by itself, but
the resulting self-resonance lies well above 100 MHz, so I guess it
shouldn't make much difference at 25 MHz.)

why would you guess that?

at the SRF the stray cap will make the inductor look like
__infinity__.

At 25 MHz the effect is still significant and will increase the
apparent inductance.

I would take inductance readings at several frequencies and examine
the slope of the inductance vs freq. for a clue.

or add an additional know value of "stray cap" and observe the effect
on measured inductance.

That may make sense, thanks.

> I think the issue IS the stray capacitance.

I've tried to fit an RLC ((R + L) || C) model over the data,
and while I'm still getting some inconsistencies with that,
it appears that a 0.8 pF stray capacitance indeed explains
an apparent increase of inductance (which seems to slightly
decrease with frequency in this model) for one of the coils.

One problem is that the coils seemingly most affected were
in parallel to rather large (no less than 470 pF) capacitors,
so a stray cap of a fraction of pF shouldn't have made any
difference. But perhaps our RLC meter was miscalibrated.

Now, I wonder if a 0.8 pF stray capacitance coil in series with
an about 15 pF capacitor would make a resonator adequate to our
needs.

--
FSF associate member #7257 http://am-1.org/~ivan/

 

[Les Cargill]

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 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?

--
Les Cargill

 

[Les Cargill]

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 ).

In 1997.
Win 95 would choke and crash under a tenth of that workload. But BeOS
couldn't run 10 year old DOS productivity software. BeOS is gone with
the snows of yesteryear.

--
Les Cargill

 

On Wed, 21 Feb 2018 16:26:16 -0800 (PST), Phil Allison
<pallison49@gmail.com> wrote:

upsid...@downunder.com wrote:

-----------------------------

** The filaments are hot all the time.

Take a look at an old or dead fluoro tube and see what the ends look like.


At least in 220-240 Vac countries, the heater is on only during the
start sequence.


** The context for my remark has been snipped - see if you can find it.

I quoted your whole previous post, so do not accuse me for snipping
your post.


** I didn't accuse you, read what I wrote.



** Fraid filaments and cathodes are one and the same. The tube's
running current passes through the filaments constantly HEATING them.


Are the electrons flying in the tube smart enough that they hit the
unconnected end of the filament, then run through the filament and
then into the connected pin ?


** The filament has only a few ohm resistance so the same potential all over, they land anywhere on it.


https://en.wikipedia.org/wiki/File:Tanninglampend.jpg


Most likely the electron hit the ring electrode around the filament
and then flow into the connected pin or at least a very short distance
of the filament closest to the connected pin.

** The ring ( where fitted) is ISOLATED - it says so in the notes.

It only acts to reduce blackening on tube ends.


The strong current
(several hundred mA) hits the ring heating it up and works as a
cathode the next half cycle.


** Even though it is isolated ?

Look closely at the picture to the right. There are two extensions
pointing at the ring at the end of each pin. The voltage drop across
this small gap is _much_ lower than the voltage drop in the long tube.
This work fine, no matter which pin is connected to the external
circuit. The lamp current flows from the ring over the small gap
directly to the pin.

Get real.


Ordinary electronic tube anodes can run red hot due to the electrons
hitting the anode.


** There is NO comparison with electron tubes which enjoy a hard vacuum.



.... Phil

 

[John Larkin]

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?


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[Phil Allison]

upsid...@downunder.com wrote:

-------------------------------

** Fraid filaments and cathodes are one and the same. The tube's
running current passes through the filaments constantly HEATING them.


Are the electrons flying in the tube smart enough that they hit the
unconnected end of the filament, then run through the filament and
then into the connected pin ?


** The filament has only a few ohm resistance so the same potential all over, they land anywhere on it.


https://en.wikipedia.org/wiki/File:Tanninglampend.jpg


Most likely the electron hit the ring electrode around the filament
and then flow into the connected pin or at least a very short distance
of the filament closest to the connected pin.

** The ring ( where fitted) is ISOLATED - it says so in the notes.

It only acts to reduce blackening on tube ends.


The strong current
(several hundred mA) hits the ring heating it up and works as a
cathode the next half cycle.


** Even though it is **isolated** ?


Look closely at the picture to the right. There are two extensions
pointing at the ring at the end of each pin. The voltage drop across
this small gap is _much_ lower than the voltage drop in the long tube.

** So is very small.

This work fine, no matter which pin is connected to the external
circuit.

** Wot UTTER BULLSHIT !!!!!!!!!!!!

The lamp current flows from the ring over the small gap
directly to the pin.

** Most fluoro tubes have no such ring which only acts to reduce blackening on tube ends.

Go away fool.



..... Phil

 

[Steve Wilson]

John Larkin <jjlarkin@highlandtechnology.com> wrote:

> This is, to me, a new way of using the LM317. I thought I'd share it.

To me, it is amazing that a device can take such a horrible whacking and
recover so gracefully. This is in a device that has zero phase shift at DC
and a constant voltage difference between the output and the feedback pin.

Before we terrorize users with the response to transient pulses, the
behaviour is much more docile with softer loads. Here's the result with a
sine wave load. The behavior is very much the same with huge variations in
load and adj cap values and load current. It is very well behaved.

Version 4
SHEET 1 1184 680
WIRE 64 128 -96 128
WIRE 368 128 320 128
WIRE 400 128 368 128
WIRE 512 128 480 128
WIRE 624 128 512 128
WIRE 688 128 624 128
WIRE 752 128 688 128
WIRE 368 144 368 128
WIRE -96 160 -96 128
WIRE 512 160 512 128
WIRE 624 160 624 128
WIRE -96 272 -96 240
WIRE 512 272 512 224
WIRE 624 304 624 240
WIRE 192 336 192 224
WIRE 336 336 192 336
WIRE 368 336 368 224
WIRE 368 336 336 336
WIRE 368 352 368 336
WIRE 192 368 192 336
WIRE 624 400 624 384
WIRE 192 448 192 432
WIRE 368 464 368 432
WIRE 192 544 192 528
FLAG -96 272 0
FLAG 368 464 0
FLAG -96 128 IN
FLAG 512 272 0
FLAG 688 128 OUT
FLAG 192 544 0
FLAG 336 336 R1R2
FLAG 368 128 R1R4
FLAG 624 400 0
SYMBOL voltage -96 144 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 15
SYMBOL res 352 128 R0
SYMATTR InstName R1
SYMATTR Value 470
SYMBOL res 352 336 R0
SYMATTR InstName R2
SYMATTR Value 3242
SYMBOL LT317A 192 128 R0
SYMATTR InstName U1
SYMBOL cap 496 160 R0
SYMATTR InstName C1
SYMATTR Value 1u
SYMBOL cap 176 368 R0
SYMATTR InstName C2
SYMATTR Value 10n
SYMBOL res 176 432 R0
SYMATTR InstName R3
SYMATTR Value 20m
SYMBOL res 496 112 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R4
SYMATTR Value 1u
SYMBOL res 608 144 R0
SYMATTR InstName R5
SYMATTR Value 100
SYMBOL voltage 624 288 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V2
SYMATTR Value SINE(0 1 1e3)
TEXT 72 -16 Left 2 !.tran 4m
TEXT 80 -40 Left 2 ;'LT317A Sine Wave Load

 

[bitrex]

On 02/21/2018 10:22 AM, Long Hair wrote:

bitrex wrote:

snip

Someone should design a security system that when e.g. an infrared beam
on the front stoop is broken it paints a half-dozen red dots on the
person standing there from strategically placed lasers all around the
property it's unobtrusive yet probably attention-getting

Until the one that points up at the overhead aircraft gets you some
federal charges.

Remeber those little disc guns we used to shoot at each other?

I would place a simple "slot" on the side of the doorway (or top) with
the gun inside, behond the slot. Very sharp or star tipped discs could
then be launched at any swing angle and folks... sharp discs go right
through Kevlar armor, and many other things.

So, an unsuspecting victim would not even know that he was staring
death right in the face.

There are no door-to-door salesmen in Colorado. Why? Because the
owner can shoot your ass as soon as you cross the perimeter of his
property, much less waiting till you get to the door. Maybe that fear
alone is a good security upgrade.

Still didn't help folks like Versace or John Lennon

Is door-to-door sales still a thing? Can't say I've ever encountered one
knocking on my door in Massachusetts for as long as I've been old enough
to have my own place (15 years or so.)

Except for girl scout cookies/high school fundraisers, maybe

 

[Steve Wilson]

Steve Wilson <no@spam.com> wrote:

John Larkin <jjlarkin@highlandtechnology.com> wrote:

This is, to me, a new way of using the LM317. I thought I'd share it.

To me, it is amazing that a device can take such a horrible whacking and
recover so gracefully. This is in a device that has zero phase shift at
DC and a constant voltage difference between the output and the feedback
pin.

Before we terrorize users with the response to transient pulses, the
behaviour is much more docile with softer loads. Here's the result with
a sine wave load. The behavior is very much the same with huge
variations in load and adj cap values and load current. It is very well
behaved.

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.

The article is also on p204 in Appendix C of Bob Pease's book titled
"Troubleshooting Analog Circuits". There is a a copy online. Scroll down to
page 204 to read it:

https://www.slideshare.net/jrbb2000/105768251-troubleshootinganalogcircuits

There is a series of Bob's articles at

http://www.introni.it/riviste_bob_pease.html

There is a possibility that the Dietz paper may be included in them, but it
will take a while to look for it.

 

[Steve Wilson]

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.

The article is also on p204 in Appendix C of Bob Pease's book titled
"Troubleshooting Analog Circuits". There is a a copy online. Scroll down
to page 204 to read it:

https://www.slideshare.net/jrbb2000/105768251-troubleshootinganalogcircui
ts

There is a series of Bob's articles at

http://www.introni.it/riviste_bob_pease.html

There is a possibility that the Dietz paper may be included in them, but
it will take a while to look for it.

Ha! There is a better source at

http://b-ok.org/book/767820/de94cb

It is on page 201. You need WinDjView to read it, which you can get at

https://windjview.sourceforge.io/

 

[Robert Baer]

Long Hair wrote:

Winfield Hill wrote:

Neon John wrote...

I haven't gotten anything in the last couple of weeks.

Ah, we're dead. That would explain a lot.


You have books... So you must be a dead poet. ;-)

I notice that you have been talking to yourself multiple times here
with nobody responding.
Lonely hearts club???

 

On Thursday, February 22, 2018 at 7:53:54 PM UTC+11, Robert Baer wrote:

Long Hair wrote:
Winfield Hill wrote:

Neon John wrote...

I haven't gotten anything in the last couple of weeks.

Ah, we're dead. That would explain a lot.


You have books... So you must be a dead poet. ;-)

I notice that you have been talking to yourself multiple times here
with nobody responding.
Lonely hearts club???

 

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.

 

[TTman]

As I said, it is a long time since I have read the regulations, and
don't have any of them at hand. Certainly I have no interest in looking
up this stuff for you.

Then you need to read the relevant regulations.

But let me repeat - if you have lights that risk causing temporary
blindness or distracting or startling other drivers, you are driving
dangerously. The police don't need any other regulations or rules if
they catch you - "dangerous driving" is an umbrella that covers a wide
range of offences. In particular, if there is an accident and the other
guy claims to have been blinded, and the court shows you have unusually
bright headlights that can reasonably be expected to cause problems for
other drivers, then they will throw the book at you. There is no need
to quote a particular rule - you are required to drive safely and
considerately.

What utter bollox. Before you can be prosecuted for something, you have
to have contravened a regulation. If all your 'optional' lighting is
installed and operated withing the relevant statutory regulations, you
cannot be breaking the law.
Your arguments have no solid foundation.


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

 

[Long Hair]

TTman wrote:

As I said, it is a long time since I have read the regulations, and
don't have any of them at hand. Certainly I have no interest in looking
up this stuff for you.

Then you need to read the relevant regulations.

But let me repeat - if you have lights that risk causing temporary
blindness or distracting or startling other drivers, you are driving
dangerously. The police don't need any other regulations or rules if
they catch you - "dangerous driving" is an umbrella that covers a wide
range of offences. In particular, if there is an accident and the other
guy claims to have been blinded, and the court shows you have unusually
bright headlights that can reasonably be expected to cause problems for
other drivers, then they will throw the book at you. There is no need
to quote a particular rule - you are required to drive safely and
considerately.

What utter bollox. Before you can be prosecuted for something, you have
to have contravened a regulation. If all your 'optional' lighting is
installed and operated withing the relevant statutory regulations, you
cannot be breaking the law.
Your arguments have no solid foundation.

Years (decades now) ago, there was a 'thing' called "J. C. Whitney".
That was back before modern 'online' product purchases, and it was back
before headlights of today brightness levels were permitted when
operating on the roadways.

Now that some of those bright lights are factory installed elements of
newly produced cars, it would appear that the laws were relaxed, and
they are friggin' everywhere. And now we have LED headlamps hitting the
scene. How quaint. Folks who cannot see driving with "light it up like
daylight" headlights on so *they* can see all the while blinding
everyone they approach. Oh and lucky you, they were owner installed
and aimed.

 

On Tuesday, February 20, 2018 at 10:24:53 AM UTC-5, olds...@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....

Good drivers learn to anticipate the road direction well in advance and don't need every little thing lit up like a Christmas tree to figure out where to steer.

 

[Winfield Hill]

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.


--
Thanks,
- Win

 

[John Larkin]

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.




--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[Phil Hobbs]

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.

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


--
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