Rail to Rail output stage for 2A 5V

[Winfield Hill]

Clifford Heath wrote...

On 15/6/19 12:00 pm, Winfield Hill wrote:
Clive Arthur wrote...
On 14/06/2019 17:13, Winfield Hill wrote:
Let me warn you that MOSFET SPICE models are horrible...
You need bench, not SPICE measurements, before talking
about looking good.
You can take simple bench measurements on your preferred
MOSFET types, and create accurate SPICE models.
Bench measurements rule.

Winfield, many thanks for sharing.

How would you go about modeling the large RF LDMOS FETs? Would these
simple bench measurements be useful at all? We are reverse engineering
the PCB design of an old VHF (225MHz) linear amp used for analog TV,
which used BLF278s. The aim is to create a SPICE model that will allow
us to scale it for better operation at 144MHz (though it works ok there
already).

Oh, boy, that's really out of my league. If forced
to work on it, I suppose I might try a set of linear
parameters to represent operation at various power
levels, but to optimize high power operation, you
really need much more powerful non-linear modeling.


--
Thanks,
- Win

 

[John Larkin]

On Sat, 15 Jun 2019 02:59:54 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 6/14/19 10:00 PM, Winfield Hill wrote:
Clive Arthur wrote...

On 14/06/2019 17:13, Winfield Hill wrote:
Clive Arthur wrote...

I have a nice simulation, op-amps wrapped round complementary
common source MOSFETs, which looks good ...

Let me warn you that MOSFET SPICE models are horrible
at modeling linear operating at current well below
their rated Ron-limited switching current. They get
g_m vs Id completely wrong, by factors of up to 100.

You need bench, not SPICE measurements, before talking
about looking good.

Thanks for the heads up, Win.

You can take simple bench measurements on your preferred
MOSFET types, and create accurate SPICE models. Here's a
crude draft of our AoE x-Chapter writeup on the subject,
read pages 33-39, and also some of the references there.
You can create a model that will match your subthreshold
measurements. Then SPICE will give the right answers.

(Don't worry about weird figure locations, that's the TEX
automated processing trying to decide where to put stuff.
When a publisher processes the file, a human does the job.)

https://www.dropbox.com/s/5lofu2chyc66kzr/3x.5_MOSFETs_Linear-Transistors_DRAFT_2019-04-20_WH-2.pdf?dl=0

Interesting stuff, thanks. You may have been spending too much time in
Massachusetts, though--on P. 32 you have you have a LaTeX description
environment

Avalanche. Although the very term “avalanche” evokes images of mayhem
and destruction,(25) MOSFETs are not damaged by such insults as long as
the peak and repetitive avalanche ratings of the device are respected."
(and so forth).

Footnote 25 reads, "(25) Which bothers some men. The word itself makes
some men uncomfortable."

Actual guys like nothing better than blowing up stuff.

Cheers

Phil Hobbs

Mosfets as linear amplifiers:

https://www.dropbox.com/s/4x34e1kisggy4de/ExFets.jpg?raw=1

Resistors as fuses:

mine

https://www.dropbox.com/s/5it6rgc1wxcp8ah/Ex-Resistors.JPG?raw=1

and H+H's

https://www.dropbox.com/s/gpc169hj1ilp6xa/photo01x_exploded_resistors.jpg?raw=1


The words "men" and "guys" are a bit politically incorrect, but
breaking things is sort of a Y-chromosone thing, I think. Of course,
my XX engineers enjoy blowing up things too.





--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[John Larkin]

On Sat, 15 Jun 2019 14:05:26 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

John Larkin <jjlarkin@highlandtechnology.com> wrote in
news:nos9getvn7ej1dlkkmvjmaf386ksg9ljjc@4ax.com:

On Sat, 15 Jun 2019 02:59:54 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 6/14/19 10:00 PM, Winfield Hill wrote:
Clive Arthur wrote...

On 14/06/2019 17:13, Winfield Hill wrote:
Clive Arthur wrote...

I have a nice simulation, op-amps wrapped round complementary
common source MOSFETs, which looks good ...

Let me warn you that MOSFET SPICE models are horrible
at modeling linear operating at current well below
their rated Ron-limited switching current. They get
g_m vs Id completely wrong, by factors of up to 100.

You need bench, not SPICE measurements, before talking
about looking good.

Thanks for the heads up, Win.

You can take simple bench measurements on your preferred
MOSFET types, and create accurate SPICE models. Here's a
crude draft of our AoE x-Chapter writeup on the subject,
read pages 33-39, and also some of the references there.
You can create a model that will match your subthreshold
measurements. Then SPICE will give the right answers.

(Don't worry about weird figure locations, that's the TEX
automated processing trying to decide where to put stuff.
When a publisher processes the file, a human does the job.)

https://www.dropbox.com/s/5lofu2chyc66kzr/3x.5_MOSFETs_Linear-
Tra
nsistors_DRAFT_2019-04-20_WH-2.pdf?dl=0

Interesting stuff, thanks. You may have been spending too much
time in Massachusetts, though--on P. 32 you have you have a LaTeX
description environment

Avalanche. Although the very term “avalanche” evokes images of
mayhem and destruction,(25) MOSFETs are not damaged by such
insults as long as the peak and repetitive avalanche ratings of
the device are respected." (and so forth).

Footnote 25 reads, "(25) Which bothers some men. The word itself
makes some men uncomfortable."

Actual guys like nothing better than blowing up stuff.

Cheers

Phil Hobbs

Mosfets as linear amplifiers:

https://www.dropbox.com/s/4x34e1kisggy4de/ExFets.jpg?raw=1

Resistors as fuses:

mine

https://www.dropbox.com/s/5it6rgc1wxcp8ah/Ex-Resistors.JPG?raw=1

and H+H's

https://www.dropbox.com/s/gpc169hj1ilp6xa/photo01x_exploded_resist
o
rs.jpg?raw=1


The words "men" and "guys" are a bit politically incorrect, but
breaking things is sort of a Y-chromosone thing, I think. Of
course, my XX engineers enjoy blowing up things too.


The key is the analysis of the event.

As long as all parties are ever conscious of all the elements
involved. One gains knowledge by good, strong observational skills.
Always good to make detailed observations of both as designed
operation and failure modes thereof.

Afterward, toss them a nice 2kV cap charged up.

That's really sick. The only thing I toss my co-workers is chocolate
truffles.

The Brat was captain of the Cornell softball team. She casually
reaches up and plucks flying objects out of the air. I never could
catch things.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

John Larkin <jjlarkin@highlandtechnology.com> wrote in
news:nos9getvn7ej1dlkkmvjmaf386ksg9ljjc@4ax.com:

On Sat, 15 Jun 2019 02:59:54 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 6/14/19 10:00 PM, Winfield Hill wrote:
Clive Arthur wrote...

On 14/06/2019 17:13, Winfield Hill wrote:
Clive Arthur wrote...

I have a nice simulation, op-amps wrapped round complementary
common source MOSFETs, which looks good ...

Let me warn you that MOSFET SPICE models are horrible
at modeling linear operating at current well below
their rated Ron-limited switching current. They get
g_m vs Id completely wrong, by factors of up to 100.

You need bench, not SPICE measurements, before talking
about looking good.

Thanks for the heads up, Win.

You can take simple bench measurements on your preferred
MOSFET types, and create accurate SPICE models. Here's a
crude draft of our AoE x-Chapter writeup on the subject,
read pages 33-39, and also some of the references there.
You can create a model that will match your subthreshold
measurements. Then SPICE will give the right answers.

(Don't worry about weird figure locations, that's the TEX
automated processing trying to decide where to put stuff.
When a publisher processes the file, a human does the job.)

https://www.dropbox.com/s/5lofu2chyc66kzr/3x.5_MOSFETs_Linear-
Tra
nsistors_DRAFT_2019-04-20_WH-2.pdf?dl=0

Interesting stuff, thanks. You may have been spending too much
time in Massachusetts, though--on P. 32 you have you have a LaTeX
description environment

Avalanche. Although the very term “avalanche” evokes images of
mayhem and destruction,(25) MOSFETs are not damaged by such
insults as long as the peak and repetitive avalanche ratings of
the device are respected." (and so forth).

Footnote 25 reads, "(25) Which bothers some men. The word itself
makes some men uncomfortable."

Actual guys like nothing better than blowing up stuff.

Cheers

Phil Hobbs

Mosfets as linear amplifiers:

https://www.dropbox.com/s/4x34e1kisggy4de/ExFets.jpg?raw=1

Resistors as fuses:

mine

https://www.dropbox.com/s/5it6rgc1wxcp8ah/Ex-Resistors.JPG?raw=1

and H+H's

https://www.dropbox.com/s/gpc169hj1ilp6xa/photo01x_exploded_resist
o
rs.jpg?raw=1


The words "men" and "guys" are a bit politically incorrect, but
breaking things is sort of a Y-chromosone thing, I think. Of
course, my XX engineers enjoy blowing up things too.


The key is the analysis of the event.

As long as all parties are ever conscious of all the elements
involved. One gains knowledge by good, strong observational skills.
Always good to make detailed observations of both as designed
operation and failure modes thereof.

Afterward, toss them a nice 2kV cap charged up. Keep 'em on their
toes. The only real danger would be if they used both hands for the
catch, and the leads happened to match up with one to each hand and
allow for a short term 'across-the-body' 'discharge event'. Naah...

 

John Larkin <jjlarkin@highlandtechnology.com> wrote in
news:d5v9ge9leqt4s46lhi7nmd5eenbm134i9g@4ax.com:

On Sat, 15 Jun 2019 14:05:26 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

John Larkin <jjlarkin@highlandtechnology.com> wrote in
news:nos9getvn7ej1dlkkmvjmaf386ksg9ljjc@4ax.com:

On Sat, 15 Jun 2019 02:59:54 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 6/14/19 10:00 PM, Winfield Hill wrote:
Clive Arthur wrote...

On 14/06/2019 17:13, Winfield Hill wrote:
Clive Arthur wrote...

I have a nice simulation, op-amps wrapped round
complementary
common source MOSFETs, which looks good ...

Let me warn you that MOSFET SPICE models are horrible
at modeling linear operating at current well below
their rated Ron-limited switching current. They get
g_m vs Id completely wrong, by factors of up to 100.

You need bench, not SPICE measurements, before talking
about looking good.

Thanks for the heads up, Win.

You can take simple bench measurements on your preferred
MOSFET types, and create accurate SPICE models. Here's a
crude draft of our AoE x-Chapter writeup on the subject,
read pages 33-39, and also some of the references there.
You can create a model that will match your subthreshold
measurements. Then SPICE will give the right answers.

(Don't worry about weird figure locations, that's the TEX
automated processing trying to decide where to put stuff.
When a publisher processes the file, a human does the job.)

https://www.dropbox.com/s/5lofu2chyc66kzr/3x.5_MOSFETs_Linear-
Tra
nsistors_DRAFT_2019-04-20_WH-2.pdf?dl=0

Interesting stuff, thanks. You may have been spending too much
time in Massachusetts, though--on P. 32 you have you have a
LaTeX
description environment

Avalanche. Although the very term “avalanche” evokes images of
mayhem and destruction,(25) MOSFETs are not damaged by such
insults as long as the peak and repetitive avalanche ratings of
the device are respected." (and so forth).

Footnote 25 reads, "(25) Which bothers some men. The word itself
makes some men uncomfortable."

Actual guys like nothing better than blowing up stuff.

Cheers

Phil Hobbs

Mosfets as linear amplifiers:

https://www.dropbox.com/s/4x34e1kisggy4de/ExFets.jpg?raw=1

Resistors as fuses:

mine

https://www.dropbox.com/s/5it6rgc1wxcp8ah/Ex-Resistors.JPG?raw=1

and H+H's


https://www.dropbox.com/s/gpc169hj1ilp6xa/photo01x_exploded_resist
o
rs.jpg?raw=1


The words "men" and "guys" are a bit politically incorrect, but
breaking things is sort of a Y-chromosone thing, I think. Of
course, my XX engineers enjoy blowing up things too.


The key is the analysis of the event.

As long as all parties are ever conscious of all the elements
involved. One gains knowledge by good, strong observational
skills.
Always good to make detailed observations of both as designed
operation and failure modes thereof.

Afterward, toss them a nice 2kV cap charged up.

That's really sick.

It is not sick, you asshole. It is harmless.

It isn't like you are tossing them a fucking 100 Lb Maxwell unit.

I said a NICE 2kV cap. not a harmful one.

 

On Saturday, 15 June 2019 14:39:51 UTC+1, John Larkin wrote:

The words "men" and "guys" are a bit politically incorrect, but
breaking things is sort of a Y-chromosone thing, I think. Of course,
my XX engineers enjoy blowing up things too.

I never related to that. While others in school wanted to destroy everything, I fixed things. I learnt electronics from nothing through fixing things. The formal qualifications later didn't add much. So I had some nice things, a growing collection of testgear & pocket money, they had nothing.


NT

 

[John Larkin]

On Sat, 15 Jun 2019 15:16:25 -0700 (PDT), tabbypurr@gmail.com wrote:

On Saturday, 15 June 2019 14:39:51 UTC+1, John Larkin wrote:

The words "men" and "guys" are a bit politically incorrect, but
breaking things is sort of a Y-chromosone thing, I think. Of course,
my XX engineers enjoy blowing up things too.

I never related to that. While others in school wanted to destroy everything, I fixed things. I learnt electronics from nothing through fixing things. The formal qualifications later didn't add much. So I had some nice things, a growing collection of testgear & pocket money, they had nothing.


NT

What, no explosives, capacitor discharge banks, nitrogen tri-iodide,
bricks tossed at picture tubes?

Now that I'm almost grown up, I like to find out what the real abs max
limits are on parts. Sometimes it's 3x or 5x what's on the data sheet.
Sometimes the data sheet just doesn't say.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[Winfield Hill]

John Larkin wrote...

Now that I'm almost grown up, I like to find out
what the real abs max limits are on parts. ...

That's engineering research, not kids blowing
stuff up.


--
Thanks,
- Win

 

[Lasse Langwadt Christense]

søndag den 16. juni 2019 kl. 01.45.13 UTC+2 skrev Winfield Hill:

John Larkin wrote...

Now that I'm almost grown up, I like to find out
what the real abs max limits are on parts. ...

That's engineering research, not kids blowing
stuff up.

https://youtu.be/BSUMBBFjxrY

 

[Jan Panteltje]

On a sunny day (15 Jun 2019 16:45:03 -0700) it happened Winfield Hill
<winfieldhill@yahoo.com> wrote in <qe3vtv02abo@drn.newsguy.com>:

John Larkin wrote...

Now that I'm almost grown up, I like to find out
what the real abs max limits are on parts. ...

That's engineering research, not kids blowing
stuff up.

I have not blown up things in decades, except my WiFi booster on the wrong power adaptor
some month ago (careless).
And propellers of my drone, flying into trees, while testing auto-pilot software.

It makes little sense, if you want to sell something at the edge of breakdown,
so out of spec, the risk is that it WILL breakdown.
Repair by others becomes difficult, the next new part they buy may fail immediately.
Manufacturing tolerances and changes.

I like to repair stuff.
The art of designing is to make things that last.
I know the art of profit is to make things with limited lifetime
from light bulbs to cellphones...

As a kid, in highschool, worst I did was put a bottle with some stuff
that reacted and after some time popped a lid from pressure with a bang under the teachers desk.

Some other kid had his own chem lab at home, made rockets...

 

[John Larkin]

On Sun, 16 Jun 2019 05:33:10 GMT, Jan Panteltje
<pNaOnStPeAlMtje@yahoo.com> wrote:

On a sunny day (15 Jun 2019 16:45:03 -0700) it happened Winfield Hill
winfieldhill@yahoo.com> wrote in <qe3vtv02abo@drn.newsguy.com>:

John Larkin wrote...

Now that I'm almost grown up, I like to find out
what the real abs max limits are on parts. ...

That's engineering research, not kids blowing
stuff up.

I have not blown up things in decades, except my WiFi booster on the wrong power adaptor
some month ago (careless).
And propellers of my drone, flying into trees, while testing auto-pilot software.

It makes little sense, if you want to sell something at the edge of breakdown,
so out of spec, the risk is that it WILL breakdown.

It makes sense to know where that edge is.



--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

On Sunday, 16 June 2019 00:38:45 UTC+1, John Larkin wrote:

On Sat, 15 Jun 2019 15:16:25 -0700 (PDT), tabbypurr wrote:
On Saturday, 15 June 2019 14:39:51 UTC+1, John Larkin wrote:

The words "men" and "guys" are a bit politically incorrect, but
breaking things is sort of a Y-chromosone thing, I think. Of course,
my XX engineers enjoy blowing up things too.

I never related to that. While others in school wanted to destroy everything, I fixed things. I learnt electronics from nothing through fixing things. The formal qualifications later didn't add much. So I had some nice things, a growing collection of testgear & pocket money, they had nothing.

What, no explosives, capacitor discharge banks, nitrogen tri-iodide,
bricks tossed at picture tubes?

I used to fix those TVs. Before the brick not after I fixed some crazy stuff as experiments. CRTs with zero emission, a very nice TV half crushed & mostly underwater, burnt out stuff, a TV with an entire board missing, etc etc.

My first thermostatic soldering iron was found crushed. The handle must have been in 20 or 30 pieces. Soon had that going. TVs, batteries, stereos, vintage lighting, all sorts of history pieces, you name it. Most people spend decades paying for everything they want in life. Why? Because it never occurred to them to learn useful life skills, or to do something more useful than watch tv.

Now that I'm almost grown up, I like to find out what the real abs max
limits are on parts. Sometimes it's 3x or 5x what's on the data sheet.
Sometimes the data sheet just doesn't say.

I did some of that in my teens. Didn't like it when things broke though. So my data was based on minimal sample sets. Soon found you could get way more from mains transformers at limited duty cycle. And some ICs. and... a lot of things.


NT

 

[Jan Panteltje]

On a sunny day (Sun, 16 Jun 2019 03:09:46 -0700) it happened John Larkin
<jjlarkin@highlandtechnology.com> wrote in
<g95cget1mkfvhd97mog2bnhur5dt3nu5t1@4ax.com>:

On Sun, 16 Jun 2019 05:33:10 GMT, Jan Panteltje
pNaOnStPeAlMtje@yahoo.com> wrote:

On a sunny day (15 Jun 2019 16:45:03 -0700) it happened Winfield Hill
winfieldhill@yahoo.com> wrote in <qe3vtv02abo@drn.newsguy.com>:

John Larkin wrote...

Now that I'm almost grown up, I like to find out
what the real abs max limits are on parts. ...

That's engineering research, not kids blowing
stuff up.

I have not blown up things in decades, except my WiFi booster on the wrong power adaptor
some month ago (careless).
And propellers of my drone, flying into trees, while testing auto-pilot software.

It makes little sense, if you want to sell something at the edge of breakdown,
so out of spec, the risk is that it WILL breakdown.

It makes sense to know where that edge is.

Sure, datasheets say that too
The problem is for repair people who will replace with the same component number.
The manufacturer will have made a new run and is still within specs,
but the poor repair guy will be stuck, very expensive for buyers!

I would not allow that practice.

 

[Winfield Hill]

Jan Panteltje wrote...

On 16 Jun 2019, John Larkin wrote

It makes sense to know where that edge is.

Sure, datasheets say that too
The problem is for repair people who will replace with
the same component number. The manufacturer will have
made a new run and is still within specs, but the poor
repair guy will be stuck, very expensive for buyers!

I would not allow that practice.

That's excessively severe, there are many important
aspects that datasheets don't deal with at all, and
others where they completely fail to do their job.

Paul and I have been collecting certain kinds of
parts for about 40 years now, and we have made
sets of measurements to see how much "typical"
parameters drift with time, and presumably with
process changes. We have also repeatedly tested
say 100 pieces from a batch. What we've found
is often there's a very high level of matching
in a batch, and the decade-to-decade drift is
often remarkably low. It's worth investigating.
There's much to learn beyond the datasheet info.


--
Thanks,
- Win

 

[Jan Panteltje]

On a sunny day (16 Jun 2019 06:15:37 -0700) it happened Winfield Hill
<winfieldhill@yahoo.com> wrote in <qe5fdp01gov@drn.newsguy.com>:

Jan Panteltje wrote...

On 16 Jun 2019, John Larkin wrote

It makes sense to know where that edge is.

Sure, datasheets say that too
The problem is for repair people who will replace with
the same component number. The manufacturer will have
made a new run and is still within specs, but the poor
repair guy will be stuck, very expensive for buyers!

I would not allow that practice.

That's excessively severe, there are many important
aspects that datasheets don't deal with at all, and
others where they completely fail to do their job.

Paul and I have been collecting certain kinds of
parts for about 40 years now, and we have made
sets of measurements to see how much "typical"
parameters drift with time, and presumably with
process changes. We have also repeatedly tested
say 100 pieces from a batch. What we've found
is often there's a very high level of matching
in a batch, and the decade-to-decade drift is
often remarkably low. It's worth investigating.
There's much to learn beyond the datasheet info.

Sure investigate anything you want.
I was reading those MOSFET specs you recently published here,
very interesting.
But using things out of spec is a nono in many fields.
I sure hope Boeing does not work that way.
In broadcasting if you can find the error in 15 minutes and replace the transistor
and it then blows up again, the hourly cost of a studio full of artists,
many of whom can only be contracted once, is mind boggling.
There is almost always some redundancy, but time is limited,
complexity is enormous.
Real world is different from a lab setting where you can just tinker all day
to get it right.
We had a very high quality acceptance lab, not sure they would accept the practice if they knew about it.
And then we are talking about equipment that costs a quarter of a million dollars a piece and that was years ago.
Not that accepted things did not break down, or did not need modification,
that happened all the time, but in consensus with the manufacturers.

Bad practices are better avoided.

 

[Cursitor Doom]

On Sun, 16 Jun 2019 05:33:10 +0000, Jan Panteltje wrote:

As a kid, in highschool, worst I did was put a bottle with some stuff
that reacted and after some time popped a lid from pressure with a bang
under the teachers desk.

At 13 or so I used to try to impress the girls by fire breathing. I'd
take one of those little butane lighter filler cans, press it up against
my front teeth and immediately the gas blew my cheeks out with the
pressurised butane gas. I'd then sneak up behind a girl I fancied and
blow it out at her whilst holding a lighter up some inches in front of my
mouth. My god did they jump! Sometimes their hair would catch fire and
I'd play the hero and put it out. The strategy never once worked, though.
I got no dates at all out of it. Miserable bitches.




--
This message may be freely reproduced without limit or charge only via
the Usenet protocol. Reproduction in whole or part through other
protocols, whether for profit or not, is conditional upon a charge of
GBP10.00 per reproduction. Publication in this manner via non-Usenet
protocols constitutes acceptance of this condition.

 

[John Larkin]

On Sun, 16 Jun 2019 14:30:16 -0000 (UTC), Cursitor Doom
<curd@notformail.com> wrote:

On Sun, 16 Jun 2019 05:33:10 +0000, Jan Panteltje wrote:

As a kid, in highschool, worst I did was put a bottle with some stuff
that reacted and after some time popped a lid from pressure with a bang
under the teachers desk.

At 13 or so I used to try to impress the girls by fire breathing. I'd
take one of those little butane lighter filler cans, press it up against
my front teeth and immediately the gas blew my cheeks out with the
pressurised butane gas. I'd then sneak up behind a girl I fancied and
blow it out at her whilst holding a lighter up some inches in front of my
mouth. My god did they jump! Sometimes their hair would catch fire and
I'd play the hero and put it out. The strategy never once worked, though.
I got no dates at all out of it. Miserable bitches.

The first time I met my wife, I bought her dinner and fixed her car. I
just didn't think to set her hair on fire.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[Cursitor Doom]

On Sun, 16 Jun 2019 07:39:55 -0700, John Larkin wrote:

The first time I met my wife, I bought her dinner and fixed her car. I
just didn't think to set her hair on fire.

That's probably where I went wrong, then.
Another dumb thing I did when young and stupid was to try to make
nitroglycerine. I saw this episode of Casey Jones where Casey and his
crew have to *delicately* transport several kegs of TNG over the railway
to some mining site where the miners are all trapped underground by a
rockfall and need to be blasted free. I already had some 70% concentrated
nitric acid in my collection; just had to go to Boots to get some
glycerine and I was away. It didn't quite work, though. When I dropped a
tiny amount from a test tube onto the ground like the guy in Casey Jones
had done, it didn't violently explode; just fizzed like soda.
Fortunately, I was unaware at that time of the importance of sulphuric
acid to the reaction or I wouldn't be typing this now. I had some 98%
sulphuric acid "in stock" at that time too! Sometimes ignorance protects
you.



--
This message may be freely reproduced without limit or charge only via
the Usenet protocol. Reproduction in whole or part through other
protocols, whether for profit or not, is conditional upon a charge of
GBP10.00 per reproduction. Publication in this manner via non-Usenet
protocols constitutes acceptance of this condition.

 

[John Larkin]

On Sun, 16 Jun 2019 16:05:21 -0000 (UTC), Cursitor Doom
<curd@notformail.com> wrote:

On Sun, 16 Jun 2019 07:39:55 -0700, John Larkin wrote:

The first time I met my wife, I bought her dinner and fixed her car. I
just didn't think to set her hair on fire.

That's probably where I went wrong, then.
Another dumb thing I did when young and stupid was to try to make
nitroglycerine. I saw this episode of Casey Jones where Casey and his
crew have to *delicately* transport several kegs of TNG over the railway
to some mining site where the miners are all trapped underground by a
rockfall and need to be blasted free. I already had some 70% concentrated
nitric acid in my collection; just had to go to Boots to get some
glycerine and I was away. It didn't quite work, though. When I dropped a
tiny amount from a test tube onto the ground like the guy in Casey Jones
had done, it didn't violently explode; just fizzed like soda.
Fortunately, I was unaware at that time of the importance of sulphuric
acid to the reaction or I wouldn't be typing this now. I had some 98%
sulphuric acid "in stock" at that time too! Sometimes ignorance protects
you.

We found a big paper bag full of shotgun shells in the closet of a
vacant house. We had fun that summer.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics