Conical inductors--still $10!...

[Bill Sloman]

On Thursday, July 16, 2020 at 4:01:59 AM UTC+10, Ricketty C wrote:

On Wednesday, July 15, 2020 at 12:19:04 PM UTC-4, Jim Jackson wrote:
Maybe I should just give in and limit the voltage with a Zener diode.
I was trying to keep a part off the BOM if possible. There\'s already
a green LED in use.

I think you will find a zener to be worse than a LED

Worse in what regard exactly??? My only real complaint with the LED is the light sensitivity. At the voltages I need to measure (up to 1.7 volts) the dark current would seem to be very minimal.

If the current at low voltages is truly logarithmic, does that mean there is a current at zero or even negative voltages? So a diode will pump out very low levels of power? Perhaps the level of power is below the uncertainty principle level of detection like the quantum foam?

https://en.wikipedia.org/wiki/Shockley_diode_equation

The current a low levels - roughly within 26mV of zero - looks resistive.

At negative voltages it is insensitive to voltage - the charge carriers appearing get swept out until you get to a high enough voltage to sustain avalanche multiplication.

Letting light shine on an LED does generate charge carriers in the junction - they aren\'t great photo-diodes, but they can be used that way.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Thursday, July 16, 2020 at 4:01:59 AM UTC+10, Ricketty C wrote:

On Wednesday, July 15, 2020 at 12:19:04 PM UTC-4, Jim Jackson wrote:
Maybe I should just give in and limit the voltage with a Zener diode.
I was trying to keep a part off the BOM if possible. There\'s already
a green LED in use.

I think you will find a zener to be worse than a LED

Worse in what regard exactly??? My only real complaint with the LED is the light sensitivity. At the voltages I need to measure (up to 1.7 volts) the dark current would seem to be very minimal.

If the current at low voltages is truly logarithmic, does that mean there is a current at zero or even negative voltages? So a diode will pump out very low levels of power? Perhaps the level of power is below the uncertainty principle level of detection like the quantum foam?

https://en.wikipedia.org/wiki/Shockley_diode_equation

The current a low levels - roughly within 26mV of zero - looks resistive.

At negative voltages it is insensitive to voltage - the charge carriers appearing get swept out until you get to a high enough voltage to sustain avalanche multiplication.

Letting light shine on an LED does generate charge carriers in the junction - they aren\'t great photo-diodes, but they can be used that way.

--
Bill Sloman, Sydney

 

[bitrex]

On 7/15/2020 9:37 PM, bitrex wrote:

On 7/15/2020 4:07 PM, Ricketty C wrote:
On Wednesday, July 15, 2020 at 8:01:28 AM UTC-4, Bob Engelhardt wrote:
On 7/15/2020 12:16 AM, Bill Sloman wrote:
...if
It probably won\'t work on John Larkin who ...

This is getting really old.  Why don\'t you give it a rest?

Give what a rest exactly?  Providing information that others wish to
minimize or directly addressing the shortcomings of Larkin?

I would be happy to never mention Larkin and the pandemic again if
Larkin stops spouting his crapola.

I mean really... first he tries to tie minor flareups in countries in
their winter season as if it were the second wave of the pandemic,
then tries to tie massive flareups in the southern US to the use of
air conditioning while totally ignoring the opening of such areas.

Larkin just refuses to accept the very clear and very easily
understood connection between disease spreading behavior and the
spread of the disease.  It\'s almost like he has a compulsion.

I think I respond to Larkin\'s irrational behavior so strongly because
to me he represents the illogical thinking of many of our
politicians.  At least the politicians have an excuse in that they
don\'t understand the basic math of a pandemic.  Oh yeah, Larkin isn\'t
so good with math either.


Republicans are like \"By God if we don\'t open up these schools we\'ve
intentionally underfunded for years and have Americas kids get back to
learning about history and math and science and other stuff we ignore
and laugh at and don\'t give a shit about it\'s going to be a total
catastrophe\"

/shrug

You\'d think the fahkas would be happy if every American kid got to stay
home at home-school and learn that babies come from storks and the Earth
is 8000 years old

 

[Ricketty C]

At one point, I thought I had it figured out. I knew that exponential growth meant that the total number of infections would be described by the equation e^x, as well as the first derivative being e^x and even the second derivative being e^x. But recently I found out by careful examination that the third derivative is also e^x!!! Who knew??!!!

Sometimes math is pretty amazing... I wonder what the fourth derivative is....

I don\'t know about this math stuff so much. Maybe Larkin is right and it\'s all about climate change. Wait, isn\'t that something he is also in denial about?

Is Larking just screwing with us???

--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209

 

[Ricketty C]

At one point, I thought I had it figured out. I knew that exponential growth meant that the total number of infections would be described by the equation e^x, as well as the first derivative being e^x and even the second derivative being e^x. But recently I found out by careful examination that the third derivative is also e^x!!! Who knew??!!!

Sometimes math is pretty amazing... I wonder what the fourth derivative is....

I don\'t know about this math stuff so much. Maybe Larkin is right and it\'s all about climate change. Wait, isn\'t that something he is also in denial about?

Is Larking just screwing with us???

--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209

 

[Ricketty C]

At one point, I thought I had it figured out. I knew that exponential growth meant that the total number of infections would be described by the equation e^x, as well as the first derivative being e^x and even the second derivative being e^x. But recently I found out by careful examination that the third derivative is also e^x!!! Who knew??!!!

Sometimes math is pretty amazing... I wonder what the fourth derivative is....

I don\'t know about this math stuff so much. Maybe Larkin is right and it\'s all about climate change. Wait, isn\'t that something he is also in denial about?

Is Larking just screwing with us???

--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209

 

[Ricketty C]

On Wednesday, July 15, 2020 at 10:21:40 PM UTC-4, Bill Sloman wrote:

On Thursday, July 16, 2020 at 4:01:59 AM UTC+10, Ricketty C wrote:
On Wednesday, July 15, 2020 at 12:19:04 PM UTC-4, Jim Jackson wrote:
Maybe I should just give in and limit the voltage with a Zener diode.
I was trying to keep a part off the BOM if possible. There\'s already
a green LED in use.

I think you will find a zener to be worse than a LED

Worse in what regard exactly??? My only real complaint with the LED is the light sensitivity. At the voltages I need to measure (up to 1.7 volts) the dark current would seem to be very minimal.

If the current at low voltages is truly logarithmic, does that mean there is a current at zero or even negative voltages? So a diode will pump out very low levels of power? Perhaps the level of power is below the uncertainty principle level of detection like the quantum foam?

https://en.wikipedia.org/wiki/Shockley_diode_equation

The current a low levels - roughly within 26mV of zero - looks resistive.

At negative voltages it is insensitive to voltage - the charge carriers appearing get swept out until you get to a high enough voltage to sustain avalanche multiplication.

Letting light shine on an LED does generate charge carriers in the junction - they aren\'t great photo-diodes, but they can be used that way.

I\'m in denial about the Shockley equation. I think it\'s turtles all the way down.

--

Rick C.

--+ Get 1,000 miles of free Supercharging
--+ Tesla referral code - https://ts.la/richard11209

 

[Ricketty C]

On Wednesday, July 15, 2020 at 10:21:40 PM UTC-4, Bill Sloman wrote:

On Thursday, July 16, 2020 at 4:01:59 AM UTC+10, Ricketty C wrote:
On Wednesday, July 15, 2020 at 12:19:04 PM UTC-4, Jim Jackson wrote:
Maybe I should just give in and limit the voltage with a Zener diode.
I was trying to keep a part off the BOM if possible. There\'s already
a green LED in use.

I think you will find a zener to be worse than a LED

Worse in what regard exactly??? My only real complaint with the LED is the light sensitivity. At the voltages I need to measure (up to 1.7 volts) the dark current would seem to be very minimal.

If the current at low voltages is truly logarithmic, does that mean there is a current at zero or even negative voltages? So a diode will pump out very low levels of power? Perhaps the level of power is below the uncertainty principle level of detection like the quantum foam?

https://en.wikipedia.org/wiki/Shockley_diode_equation

The current a low levels - roughly within 26mV of zero - looks resistive.

At negative voltages it is insensitive to voltage - the charge carriers appearing get swept out until you get to a high enough voltage to sustain avalanche multiplication.

Letting light shine on an LED does generate charge carriers in the junction - they aren\'t great photo-diodes, but they can be used that way.

I\'m in denial about the Shockley equation. I think it\'s turtles all the way down.

--

Rick C.

--+ Get 1,000 miles of free Supercharging
--+ Tesla referral code - https://ts.la/richard11209

 

[Ricketty C]

On Wednesday, July 15, 2020 at 10:21:40 PM UTC-4, Bill Sloman wrote:

On Thursday, July 16, 2020 at 4:01:59 AM UTC+10, Ricketty C wrote:
On Wednesday, July 15, 2020 at 12:19:04 PM UTC-4, Jim Jackson wrote:
Maybe I should just give in and limit the voltage with a Zener diode.
I was trying to keep a part off the BOM if possible. There\'s already
a green LED in use.

I think you will find a zener to be worse than a LED

Worse in what regard exactly??? My only real complaint with the LED is the light sensitivity. At the voltages I need to measure (up to 1.7 volts) the dark current would seem to be very minimal.

If the current at low voltages is truly logarithmic, does that mean there is a current at zero or even negative voltages? So a diode will pump out very low levels of power? Perhaps the level of power is below the uncertainty principle level of detection like the quantum foam?

https://en.wikipedia.org/wiki/Shockley_diode_equation

The current a low levels - roughly within 26mV of zero - looks resistive.

At negative voltages it is insensitive to voltage - the charge carriers appearing get swept out until you get to a high enough voltage to sustain avalanche multiplication.

Letting light shine on an LED does generate charge carriers in the junction - they aren\'t great photo-diodes, but they can be used that way.

I\'m in denial about the Shockley equation. I think it\'s turtles all the way down.

--

Rick C.

--+ Get 1,000 miles of free Supercharging
--+ Tesla referral code - https://ts.la/richard11209

 

[Bill Sloman]

On Thursday, July 16, 2020 at 2:13:05 AM UTC+10, jla...@highlandsniptechnology.com wrote:

On Wed, 15 Jul 2020 09:16:36 +0100, Martin Brown
\'\'\'newspam\'\'\'@nezumi.demon.co.uk> wrote:

On 14/07/2020 22:43, John Larkin wrote:
On Tue, 14 Jul 2020 21:16:22 +0200, David Brown
david.brown@hesbynett.no> wrote:

On 14/07/2020 19:50, John Larkin wrote:

<snip>

Why clearly wrong? Can 100% of a population catch this virus? 400% ?

We already know that the population vulnerability is *at least* 87% from
that hapless choir who had a symptomatic carrier in their midst.

Cool. The survivors are immune. They should volunteer to work in
nursing homes, and save some lives.

You seem completely unable to grasp the very simple fact that you have
to be exposed to the virus before you can catch it.

Now don\'t be a fathead. Try thinking once in a while maybe.

The problem here is that you are being a fathead. We\'ve frequently invited you to try to think about what you post, but it never seems to happen.

Lockdowns are why you have a tail at all in this period, rather than
continuing to have /more/ infections for a much longer period.

Or the same number of infections in a short period. Maybe even fewer
total infections.

We can watch and wait as the southern righttard states

Nobody like mindless bigots either.

And there is an element of poetic justice when their blind spots turn out to make them more likely to catch Covid19.

exercise their constitutional freedom to catch Covid-19. Only Brazil is making a more serious balls up of handling the pandemic than the USA. Both have a very long way to go before the infection gets anywhere near herd immunity.

Some recent estimates by \"experts\" put herd immunity as low as 20%.
Sounds reasonable to me.

All based on computer modelling. John Larkin trusts it when it produces a result he likes.

If you do nothing with business as usual you will see exponential growth
with a characteristic doubling time of about 3 days.

In that case, we\'re all dead. But the growth soon stops being
exponential and peaks and declines. Look it up.

But it does depend on human behavior. Presumably more intelligent people change their behavior sooner and more effectively, so the average IQ may end up higher than it was before the pandemic. Sadly, a 4% mortality rate doesn\'t kill enough people to make much of a difference and the age distribution of fatal outcomes means that most of them will have already reproduced.


> > That was what happened in the UK until they switched into lockdown. It is calculated that locking down one week sooner would have halved the death toll and meant a shorter lockdown period to get back to a traceable baseline
level. That is assuming the government managed to get track and trace
right (they didn\'t and the much vaunted UK world beating app sank
without trace).

The up-swing in the US south may well be caused by air conditioning.

Influenced by, perhaps, but not /caused/ by. The blame lies with the idiot authorities who opened up far too fast, far too much and far too soon.

Again, should they lock down forever? Opening gradually (or rather,
opening politically) just creates a long tail, with panic driven
bumps.

Not if it is done right.

> >Not exactly. You need a decent track and trace system that can close
down any local infections before they escape back into full community
transmission. This is more easily done in societies like Japan and Korea
where people trust their government and are compliant with advice. And
in China where the population have no choice but to obey the government.

USA people seem to wilfully go out of their way to court disaster.

Not much, but I think we are much less afraid, and unimpressed by
authority, than most places.

It may be more that the antiquated US political system means that the elected authorities are less impressive than they are places with better political systems.

> Selective migration did that. I wonder if recklessness is hereditary.

Attention seeking behavior in males does seem to be driven by a desire to get noticed by fertile females. As James Arthur is always reminding us, kids brought up by couples do better than kids brought up by single mothers, so any reproductive advantage from recklessness is dearly bought.

<snip>

The lockdown thing was and is grossly mismanaged. People under 40 have
a tiny mortality from this virus, and they could keep working. Spend
the trillions to protect the vulnerable; we mostly know who they are.

But it\'s not obvious that you can protect them. Aged care homes get infected remarkably often, despite their best efforts.

If our lockdowns kill more people in poor countries than they save in
mostly white developed countries (and they may not even save lives
here) then the lockdowns are racist genocide. Do Black Lives Matter in
Africa?

Silly question.

<snip>

I\'d rather catch this thing and take my chances to live or die, than
see myself and my family slowly starve to death.

Lock downs don\'t seem to be starving anybody to death.

Your choice of course but if you are male and over 60 be very careful
what you wish for. Take a very good look at the age related IFR first.

Yes, my choice. I am keeping my business alive and my employees paid.

But increasing the chances that people in your community will get infected.

And sending some fraction of our profits to fund life-changing and
life-saving medical care in Africa. If that kills me, lives are still
net saved.

Only if you are doing the math. Ignoring the potential negative consequences of you own free-loading does make you look good.

Sensible countries run their essential systems so that utilities and
food production remain available. Pretty much everything else in the UK
was shut down until about a week ago. Many office workers have found
that they can work from home more effectively than in the office - fewer
distractions and no early starts for a tedious commute into the city.

If many workers continue to work from home, which I think they will,
workers need not pack into dense, expensive cities. Don\'t invest in
WeWork.

On-line sharing is probably even cheaper than exploiting shared office space.

--
Bill Sloman, sydney

 

[Bill Sloman]

On Thursday, July 16, 2020 at 2:13:05 AM UTC+10, jla...@highlandsniptechnology.com wrote:

On Wed, 15 Jul 2020 09:16:36 +0100, Martin Brown
\'\'\'newspam\'\'\'@nezumi.demon.co.uk> wrote:

On 14/07/2020 22:43, John Larkin wrote:
On Tue, 14 Jul 2020 21:16:22 +0200, David Brown
david.brown@hesbynett.no> wrote:

On 14/07/2020 19:50, John Larkin wrote:

<snip>

Why clearly wrong? Can 100% of a population catch this virus? 400% ?

We already know that the population vulnerability is *at least* 87% from
that hapless choir who had a symptomatic carrier in their midst.

Cool. The survivors are immune. They should volunteer to work in
nursing homes, and save some lives.

You seem completely unable to grasp the very simple fact that you have
to be exposed to the virus before you can catch it.

Now don\'t be a fathead. Try thinking once in a while maybe.

The problem here is that you are being a fathead. We\'ve frequently invited you to try to think about what you post, but it never seems to happen.

Lockdowns are why you have a tail at all in this period, rather than
continuing to have /more/ infections for a much longer period.

Or the same number of infections in a short period. Maybe even fewer
total infections.

We can watch and wait as the southern righttard states

Nobody like mindless bigots either.

And there is an element of poetic justice when their blind spots turn out to make them more likely to catch Covid19.

exercise their constitutional freedom to catch Covid-19. Only Brazil is making a more serious balls up of handling the pandemic than the USA. Both have a very long way to go before the infection gets anywhere near herd immunity.

Some recent estimates by \"experts\" put herd immunity as low as 20%.
Sounds reasonable to me.

All based on computer modelling. John Larkin trusts it when it produces a result he likes.

If you do nothing with business as usual you will see exponential growth
with a characteristic doubling time of about 3 days.

In that case, we\'re all dead. But the growth soon stops being
exponential and peaks and declines. Look it up.

But it does depend on human behavior. Presumably more intelligent people change their behavior sooner and more effectively, so the average IQ may end up higher than it was before the pandemic. Sadly, a 4% mortality rate doesn\'t kill enough people to make much of a difference and the age distribution of fatal outcomes means that most of them will have already reproduced.


> > That was what happened in the UK until they switched into lockdown. It is calculated that locking down one week sooner would have halved the death toll and meant a shorter lockdown period to get back to a traceable baseline
level. That is assuming the government managed to get track and trace
right (they didn\'t and the much vaunted UK world beating app sank
without trace).

The up-swing in the US south may well be caused by air conditioning.

Influenced by, perhaps, but not /caused/ by. The blame lies with the idiot authorities who opened up far too fast, far too much and far too soon.

Again, should they lock down forever? Opening gradually (or rather,
opening politically) just creates a long tail, with panic driven
bumps.

Not if it is done right.

> >Not exactly. You need a decent track and trace system that can close
down any local infections before they escape back into full community
transmission. This is more easily done in societies like Japan and Korea
where people trust their government and are compliant with advice. And
in China where the population have no choice but to obey the government.

USA people seem to wilfully go out of their way to court disaster.

Not much, but I think we are much less afraid, and unimpressed by
authority, than most places.

It may be more that the antiquated US political system means that the elected authorities are less impressive than they are places with better political systems.

> Selective migration did that. I wonder if recklessness is hereditary.

Attention seeking behavior in males does seem to be driven by a desire to get noticed by fertile females. As James Arthur is always reminding us, kids brought up by couples do better than kids brought up by single mothers, so any reproductive advantage from recklessness is dearly bought.

<snip>

The lockdown thing was and is grossly mismanaged. People under 40 have
a tiny mortality from this virus, and they could keep working. Spend
the trillions to protect the vulnerable; we mostly know who they are.

But it\'s not obvious that you can protect them. Aged care homes get infected remarkably often, despite their best efforts.

If our lockdowns kill more people in poor countries than they save in
mostly white developed countries (and they may not even save lives
here) then the lockdowns are racist genocide. Do Black Lives Matter in
Africa?

Silly question.

<snip>

I\'d rather catch this thing and take my chances to live or die, than
see myself and my family slowly starve to death.

Lock downs don\'t seem to be starving anybody to death.

Your choice of course but if you are male and over 60 be very careful
what you wish for. Take a very good look at the age related IFR first.

Yes, my choice. I am keeping my business alive and my employees paid.

But increasing the chances that people in your community will get infected.

And sending some fraction of our profits to fund life-changing and
life-saving medical care in Africa. If that kills me, lives are still
net saved.

Only if you are doing the math. Ignoring the potential negative consequences of you own free-loading does make you look good.

Sensible countries run their essential systems so that utilities and
food production remain available. Pretty much everything else in the UK
was shut down until about a week ago. Many office workers have found
that they can work from home more effectively than in the office - fewer
distractions and no early starts for a tedious commute into the city.

If many workers continue to work from home, which I think they will,
workers need not pack into dense, expensive cities. Don\'t invest in
WeWork.

On-line sharing is probably even cheaper than exploiting shared office space.

--
Bill Sloman, sydney

 

[George Herold]

On Wednesday, July 15, 2020 at 4:53:19 PM UTC-4, Pimpom wrote:

On 7/15/2020 1:18 PM, Ricketty C wrote:
On Wednesday, July 15, 2020 at 2:47:50 AM UTC-4, Pimpom wrote:
On 7/15/2020 10:06 AM, Ricketty C wrote:
I was thinking of using a green LED to limit a measured voltage on the ADC of an MCU. However, I can\'t find a good chart of the I-V curve below 1 mA. The circuit supplies up to 1.15 mA which is measured by dropping it across a 1.5 k resistor yielding up to around 1.7 volts. This seems like it might be getting into a range where the LED might be stealing a significant portion of the current being measured. But none of the references I can find provide enough detail to know for sure. Most seem to be something along the lines of an \"artist\'s concept\" of a curve lying along the X axis until reaching some voltage where it takes off like a hockey stick. Others just seem to be a wag with only a very few points measured. None of them show any detail at the low end with 10 mA as the lowest line on the Y axis.

Anyone measured a green LED at low currents or know how they respond?

If needed, I can lower the resistor which will lower the voltage the LED will see, but I can\'t lower it too much or lose resolution of the measurement.

Maybe I should just give in and limit the voltage with a Zener diode. I was trying to keep a part off the BOM if possible. There\'s already a green LED in use.



I did a manual measurement of various no-name LEDs 10 years ago.
It included only one green 5mm LED. The current level probably
doesn\'t go as low as you want but FWIW this is what I got:

mA V

0.44 -- 2.608
0.5 --- 2.627
1 ----- 2.711
2 ----- 2.801
3 ----- 2.864
4 ----- 2.902
5 ----- 2.939
7 ----- 3.003
10 ---- 3.077
15.5 -- 3.141

Thanks for the data. That was just what I was looking for.

From that data it looks like it will have very minimal impact on the current over the voltage range of interest. But if I am using this to save adding a Zener diode but I have to have the part painted... doesn\'t seem worth the trouble. The case only has small air openings, but it has a large port on top covered by plexi so the workings can be monitored. So it will have indirect light inside the case falling on the LED. The case is stainless steel, so lots of reflection.

I wonder just how much the light will affect the LED. Low uA won\'t be a problem. 100\'s of uA will. Sounds like I should use the Zener.

I have no recorded data about the photoelectric effect but,
speaking from memory of a half-hearted test I once did, I can
assure you that it will not be hundreds of uA. I doubt that it
will even be in the \"low uA\" region under those conditions.

I measured it for one led long ago. My memory is that
sticking two led\'s face to face and driving one you
can get about 1 part per thousand of the driving current.
(maybe 1/10 that?)
(part of that measurement depends on the LED efficiency.)

I don\'t know what happens when you forward bias it and then
shine light on it. Maybe nothing?

George H.

 

[George Herold]

On Wednesday, July 15, 2020 at 4:53:19 PM UTC-4, Pimpom wrote:

On 7/15/2020 1:18 PM, Ricketty C wrote:
On Wednesday, July 15, 2020 at 2:47:50 AM UTC-4, Pimpom wrote:
On 7/15/2020 10:06 AM, Ricketty C wrote:
I was thinking of using a green LED to limit a measured voltage on the ADC of an MCU. However, I can\'t find a good chart of the I-V curve below 1 mA. The circuit supplies up to 1.15 mA which is measured by dropping it across a 1.5 k resistor yielding up to around 1.7 volts. This seems like it might be getting into a range where the LED might be stealing a significant portion of the current being measured. But none of the references I can find provide enough detail to know for sure. Most seem to be something along the lines of an \"artist\'s concept\" of a curve lying along the X axis until reaching some voltage where it takes off like a hockey stick. Others just seem to be a wag with only a very few points measured. None of them show any detail at the low end with 10 mA as the lowest line on the Y axis.

Anyone measured a green LED at low currents or know how they respond?

If needed, I can lower the resistor which will lower the voltage the LED will see, but I can\'t lower it too much or lose resolution of the measurement.

Maybe I should just give in and limit the voltage with a Zener diode. I was trying to keep a part off the BOM if possible. There\'s already a green LED in use.



I did a manual measurement of various no-name LEDs 10 years ago.
It included only one green 5mm LED. The current level probably
doesn\'t go as low as you want but FWIW this is what I got:

mA V

0.44 -- 2.608
0.5 --- 2.627
1 ----- 2.711
2 ----- 2.801
3 ----- 2.864
4 ----- 2.902
5 ----- 2.939
7 ----- 3.003
10 ---- 3.077
15.5 -- 3.141

Thanks for the data. That was just what I was looking for.

From that data it looks like it will have very minimal impact on the current over the voltage range of interest. But if I am using this to save adding a Zener diode but I have to have the part painted... doesn\'t seem worth the trouble. The case only has small air openings, but it has a large port on top covered by plexi so the workings can be monitored. So it will have indirect light inside the case falling on the LED. The case is stainless steel, so lots of reflection.

I wonder just how much the light will affect the LED. Low uA won\'t be a problem. 100\'s of uA will. Sounds like I should use the Zener.

I have no recorded data about the photoelectric effect but,
speaking from memory of a half-hearted test I once did, I can
assure you that it will not be hundreds of uA. I doubt that it
will even be in the \"low uA\" region under those conditions.

I measured it for one led long ago. My memory is that
sticking two led\'s face to face and driving one you
can get about 1 part per thousand of the driving current.
(maybe 1/10 that?)
(part of that measurement depends on the LED efficiency.)

I don\'t know what happens when you forward bias it and then
shine light on it. Maybe nothing?

George H.

 

[Ricketty C]

Trump\'s approval rating at fivethirtyeight has dropped to just 40.3%, the lowest number in 18 months. There was a brief spell when I think the government was shut down and Trump had to finally sign a bill.

Oh, and then there was a spell the September before that when he was doing something stupid I can\'t remember. Oh yeah, and then there was the time not long after his inauguration when his approval rating was under 40% for nearly a whole year. Yeah, that was pretty ugly for him.

Well, I guess he is used to this. If he could manage to actually take some effective action and deal with the virus, I think that would guarantee his reelection. But he is too focused on the economy rather than the cause of the problems with the economy.

When Kennedy had the Bay of Pigs disaster and acknowledged responsibility, his approval shot up. I have no doubt at all that Trump could do the same thing by taking the actions recommended by the experts in this area and getting control of this disease rather than denying the obvious results of reopening the country to the disease... and taking responsibility for the mistakes of the past. Yes, I think that would be a defining moment for him and assure him of reelection.

Or he can do this...

https://www.youtube.com/watch?v=G0sbYp-J84g&feature=youtu.be&t=74

--

Rick C.

++ Get 1,000 miles of free Supercharging
++ Tesla referral code - https://ts.la/richard11209

 

[Ricketty C]

Trump\'s approval rating at fivethirtyeight has dropped to just 40.3%, the lowest number in 18 months. There was a brief spell when I think the government was shut down and Trump had to finally sign a bill.

Oh, and then there was a spell the September before that when he was doing something stupid I can\'t remember. Oh yeah, and then there was the time not long after his inauguration when his approval rating was under 40% for nearly a whole year. Yeah, that was pretty ugly for him.

Well, I guess he is used to this. If he could manage to actually take some effective action and deal with the virus, I think that would guarantee his reelection. But he is too focused on the economy rather than the cause of the problems with the economy.

When Kennedy had the Bay of Pigs disaster and acknowledged responsibility, his approval shot up. I have no doubt at all that Trump could do the same thing by taking the actions recommended by the experts in this area and getting control of this disease rather than denying the obvious results of reopening the country to the disease... and taking responsibility for the mistakes of the past. Yes, I think that would be a defining moment for him and assure him of reelection.

Or he can do this...

https://www.youtube.com/watch?v=G0sbYp-J84g&feature=youtu.be&t=74

--

Rick C.

++ Get 1,000 miles of free Supercharging
++ Tesla referral code - https://ts.la/richard11209

 

[server]

On Tuesday, July 14, 2020 at 1:50:54 PM UTC-4, John Larkin wrote:

On Sun, 12 Jul 2020 21:13:37 -0700 (PDT), dagmargoodboat@yahoo.com
wrote:

On Sunday, July 12, 2020 at 11:19:34 PM UTC-4, edward...@gmail.com wrote:
You are like the people who initially protested the stay at home orders because they wanted haircuts. You are so shallow and self centered.. Yes, parking is what this pandemic is all about.

Your logic is wrong. I enjoy current parking and traffic situations, but i don\'t believe it should or will continue this way. How it that self centered?

Many office buildings are empty now and probably will never be occupied again. This cannot be a healthy city. City government living on ticket revenues can\'t last forever.

The city population density needs to be reduced and we need to reshape the area somehow. We just have to deal with the issues sooner or later.

I don\'t encourage people to protest the stay at home order. But i don\'t encourage blind strict enforcement either.

This is silly. You want strict enforcement, where it matters, for the 14 days it takes to make sure that anybody who has the infection has manifested it by testing positive for the presence of the virus.

Not enough districts in the US have done the kind of contact tracing that lets them quarantine only the people who might be infected for the 14 days from when they might have got infected.

We have been shut-down for many times of 14 days, but the virus is not going away. The 14 days period was and is just a guess. How is Australia and Beijing dealing with renew cases anyway? Contract tracing is not possible in many part of the world, including Beijing. We are way pass that point. You guys keep repeating meaningless phases.

Not to worry, the virus will suddenly be down the memory hole as
soon as the election\'s over, not a problem at all.

During H1N1 the Obama-Biden administration stopped counting cases.

quote
\"In late July, the CDC abruptly advised states to stop testing for H1N1 flu, and stopped counting individual cases. The rationale given for the CDC guidance to forego testing and tracking individual cases was: why waste resources testing for H1N1 flu when the government has already confirmed there\'s an epidemic?

Some public health officials privately disagreed with the decision to stop testing and counting, telling CBS News that continued tracking of this new and possibly changing virus was important because H1N1 has a different epidemiology, affects younger people more than seasonal flu and has been shown to have a higher case fatality rate than other flu virus strains.\"
/quote
https://www.cbsnews.com/news/swine-flu-cases-overestimated/

Can you imagine if this president did the same?

Apparently now we\'re supposed to permanently shut down the world every
time there\'s a virus anywhere. I\'m not sure people have thought this
thing through...

Cheers,
James Arthur

Looks like it has burned out in New York, as it did in many European
countries. You can\'t have 20% of a population infected, for two or
three weeks each maybe, forever, even if the herd immunity level were
100%. Which of course it isn\'t.

The characteristic new-case waveform seems to be a rounded hump (dare
I say Gaussian?) of width 5 weeks or so. Lockdowns no doubt extend the
tail and cause secondary blips when inevitably mis-managed.

The up-swing in the US south may well be caused by air conditioning.

https://wattsupwiththat.com/2020/07/14/is-air-conditioning-contributing-to-coronavirus-spread/

Australia and S Africa and Paraguay seem to be having winter bumps.

The head of the CDC commented that they think the bump in the South
coincided with Memorial Day crowds of northerners, vacationing.

I\'ve just gotten word that despite being locked down in a lock-down
state to the point of lock-down insanity, Mom\'s been exposed. So now
the wait begins.

These half-witted faux-science worshippers who haven\'t let us get
national immunity may have killed her, just as I predicted months
ago.

James

 

[server]

On Tuesday, July 14, 2020 at 1:50:54 PM UTC-4, John Larkin wrote:

On Sun, 12 Jul 2020 21:13:37 -0700 (PDT), dagmargoodboat@yahoo.com
wrote:

On Sunday, July 12, 2020 at 11:19:34 PM UTC-4, edward...@gmail.com wrote:
You are like the people who initially protested the stay at home orders because they wanted haircuts. You are so shallow and self centered.. Yes, parking is what this pandemic is all about.

Your logic is wrong. I enjoy current parking and traffic situations, but i don\'t believe it should or will continue this way. How it that self centered?

Many office buildings are empty now and probably will never be occupied again. This cannot be a healthy city. City government living on ticket revenues can\'t last forever.

The city population density needs to be reduced and we need to reshape the area somehow. We just have to deal with the issues sooner or later.

I don\'t encourage people to protest the stay at home order. But i don\'t encourage blind strict enforcement either.

This is silly. You want strict enforcement, where it matters, for the 14 days it takes to make sure that anybody who has the infection has manifested it by testing positive for the presence of the virus.

Not enough districts in the US have done the kind of contact tracing that lets them quarantine only the people who might be infected for the 14 days from when they might have got infected.

We have been shut-down for many times of 14 days, but the virus is not going away. The 14 days period was and is just a guess. How is Australia and Beijing dealing with renew cases anyway? Contract tracing is not possible in many part of the world, including Beijing. We are way pass that point. You guys keep repeating meaningless phases.

Not to worry, the virus will suddenly be down the memory hole as
soon as the election\'s over, not a problem at all.

During H1N1 the Obama-Biden administration stopped counting cases.

quote
\"In late July, the CDC abruptly advised states to stop testing for H1N1 flu, and stopped counting individual cases. The rationale given for the CDC guidance to forego testing and tracking individual cases was: why waste resources testing for H1N1 flu when the government has already confirmed there\'s an epidemic?

Some public health officials privately disagreed with the decision to stop testing and counting, telling CBS News that continued tracking of this new and possibly changing virus was important because H1N1 has a different epidemiology, affects younger people more than seasonal flu and has been shown to have a higher case fatality rate than other flu virus strains.\"
/quote
https://www.cbsnews.com/news/swine-flu-cases-overestimated/

Can you imagine if this president did the same?

Apparently now we\'re supposed to permanently shut down the world every
time there\'s a virus anywhere. I\'m not sure people have thought this
thing through...

Cheers,
James Arthur

Looks like it has burned out in New York, as it did in many European
countries. You can\'t have 20% of a population infected, for two or
three weeks each maybe, forever, even if the herd immunity level were
100%. Which of course it isn\'t.

The characteristic new-case waveform seems to be a rounded hump (dare
I say Gaussian?) of width 5 weeks or so. Lockdowns no doubt extend the
tail and cause secondary blips when inevitably mis-managed.

The up-swing in the US south may well be caused by air conditioning.

https://wattsupwiththat.com/2020/07/14/is-air-conditioning-contributing-to-coronavirus-spread/

Australia and S Africa and Paraguay seem to be having winter bumps.

The head of the CDC commented that they think the bump in the South
coincided with Memorial Day crowds of northerners, vacationing.

I\'ve just gotten word that despite being locked down in a lock-down
state to the point of lock-down insanity, Mom\'s been exposed. So now
the wait begins.

These half-witted faux-science worshippers who haven\'t let us get
national immunity may have killed her, just as I predicted months
ago.

James

 

[speff]

On Wednesday, 15 July 2020 10:32:55 UTC-4, Rob wrote:

jlarkin@highlandsniptechnology.com <jlarkin@highlandsniptechnology.com> wrote:
One of my most common causes of writing ECOs against new designs is
that the LEDs are too bright. Gotta do that again today.

It is even more true for blue leds than for green. When a device
has a blue indicator LED, it usually is far too bright. Both my PC
and my router have indicator lights that, when not taped over, cause
a large blue spot to appear on the opposite wall.

There is actually a tape sold for that purpose. Probably just opaque electrical tape. Capitalism!

I was taking a walk the other night about 3AM and kept seeing brief flashes, which made sense near the lighthouse but not so much in the middle of a park. Turned out my Sony wireless headphones do that. Dunh.

Best regards,
Spehro Pefhany

 

[speff]

On Wednesday, 15 July 2020 10:32:55 UTC-4, Rob wrote:

jlarkin@highlandsniptechnology.com <jlarkin@highlandsniptechnology.com> wrote:
One of my most common causes of writing ECOs against new designs is
that the LEDs are too bright. Gotta do that again today.

It is even more true for blue leds than for green. When a device
has a blue indicator LED, it usually is far too bright. Both my PC
and my router have indicator lights that, when not taped over, cause
a large blue spot to appear on the opposite wall.

There is actually a tape sold for that purpose. Probably just opaque electrical tape. Capitalism!

I was taking a walk the other night about 3AM and kept seeing brief flashes, which made sense near the lighthouse but not so much in the middle of a park. Turned out my Sony wireless headphones do that. Dunh.

Best regards,
Spehro Pefhany

 

[server]

On Tuesday, July 14, 2020 at 8:19:49 AM UTC-4, Phil Hobbs wrote:

Thanks to Glen, Mikko S, and James, the secret sauce page is now up. I
added a blog post with links, which will make it easier to search for.

https://electrooptical.net/News/mirror-of-wwwanalog-innovationscom-jim-thompsons-site/


The secret sauce page is typical JT, of course--just screen shots, no
actual deck. (Or plots either, but hey, the guy was pretty sick at that
point.)

Cheers

Phil Hobbs

Most gracious of you Phil, thanks.

Cheers,
James Arthur