102,400 one-shots...

On Sat, 8 Apr 2023 07:52:45 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2023-04-07 21:08, John Larkin wrote:
On Fri, 7 Apr 2023 19:24:52 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2023-04-07 16:23, John Larkin wrote:
On Fri, 7 Apr 2023 13:59:33 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

So we\'re just finishing up a lidar detector chip in collaboration
with the chip design house (who does the actual circuitry, floor
plan, and polygon-pushing) and the airplane folks.

Just between us, what did that cost?

It was surprisingly reasonable--even a dedicated engineering run (20ish
wafers) was about $50k, I think, and the multiproject wafer approach (a
la MOSIS) is considerably cheaper than that. This was on an XFAB 180 nm
process with APDs and SPADs.

We\'ve been kicking around doing the guts of a laser noise canceller on a
transistor array chip--onsemi will do that for just a few $k.

We did the original proof of concept using a dead-bug prototype
with pHEMTs and CFAs and sampling diodes and stuff, which was
enough to get the program going. At this point we\'re
subcontractors to the camera folks, basically helping with the
design, doing the demo camera, and coaching everybody. (We aren\'t
head coach--maybe offensive coordinator.) ;)

It\'s been going for a couple of years, and we\'re at the point of
taping out the first of the second-generation chips.

It contains 102,400 one-shots and 106,496 Class A amplifiers,
unless I\'ve miscounted. (We tried to get them to use a sane number
of monostables, such as 0, but couldn\'t make that one stick. They
take up less space than registers, we\'re told.)

I\'d like to do some custom mixed-signal chips. Apparently it\'s not a
totally crazy idea any more.


The power budget is going to be entertaining. ;)

A mutual friend wants me to do another driver for his electro-optical
gadget. Fast driver. How does one get rid of 60 watts on maybe half a
square inch of PCB? And not block the light?

A loop of copper tube with water running through it, or maybe a vapor
chamber heat spreader with a finned heat sink someplace nearby. Vapor
chambers are about 10x better than copper, iirc. Digikey sells them.

Charging and discharging capacitors, in principle, takes no power.

The canonical method for charging and discharging caps fast and
efficiently is to use an inductor and diode to force the charge waveform
to be half a cycle of a sine wave. That\'s how a lot of lidar laser
drivers work.

Cheers

Phil Hobbs

In theory, one can run up a parallel LC circuit and, once pumped, get
a zillion cap charge and discharge cycles for free after that.

Then, at any zero crossing, short it out for as long as you like, and
turn it loose any time after that to resume the oscillation.

Nice example of a differential equation with initial conditions.


That\'s basically the dual of the inductor + diode thing, which switches
automatically at the voltage peak.

+20V
0--LLLL-->|--*---------* 40V peak
| |
| LD Triple-stack Osram laser
few nF CCC |
CCC 0
| \\ EPC GaN FET
| 0
| |
GND GND

The Uber one I took apart a few years ago had a total inductance (around
that cap - laser - switch loop) of just under 400 pH, about half in the
source and half in the drain. (Ascertained by dorking LTspice till the
waveforms agreed with my data.)

Cheers

Phil Hobbs
Click to expand...

Jim Thompson had an elegant CD ignition circuit that worked something
like that. It was crazy simple compared to what I used to do on
motorcycles: dc/dc converters and oil caps and SCRs and stuff.

My Pockels Cell driver charges an inductor, dumps it into the
capacitive load, returns the energy to the inductor, and then dumps
that energy back into the power supply. The big problem was inductor
heating; that took three revs to get right.

Except for being crazy fragile BGAs, the EPC parts are magic. I think
they are selling a packaged part now, which they swore they would
never do.
 
> What do Germans call bubblegum? I\'d expect a very long word.

Kaugummi.
 
lørdag den 8. april 2023 kl. 16.39.18 UTC+2 skrev John Larkin:
On Sat, 8 Apr 2023 07:52:45 -0400, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

On 2023-04-07 21:08, John Larkin wrote:
On Fri, 7 Apr 2023 19:24:52 -0400, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

On 2023-04-07 16:23, John Larkin wrote:
On Fri, 7 Apr 2023 13:59:33 -0400, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

So we\'re just finishing up a lidar detector chip in collaboration
with the chip design house (who does the actual circuitry, floor
plan, and polygon-pushing) and the airplane folks.

Just between us, what did that cost?

It was surprisingly reasonable--even a dedicated engineering run (20ish
wafers) was about $50k, I think, and the multiproject wafer approach (a
la MOSIS) is considerably cheaper than that. This was on an XFAB 180 nm
process with APDs and SPADs.

We\'ve been kicking around doing the guts of a laser noise canceller on a
transistor array chip--onsemi will do that for just a few $k.

We did the original proof of concept using a dead-bug prototype
with pHEMTs and CFAs and sampling diodes and stuff, which was
enough to get the program going. At this point we\'re
subcontractors to the camera folks, basically helping with the
design, doing the demo camera, and coaching everybody. (We aren\'t
head coach--maybe offensive coordinator.) ;)

It\'s been going for a couple of years, and we\'re at the point of
taping out the first of the second-generation chips.

It contains 102,400 one-shots and 106,496 Class A amplifiers,
unless I\'ve miscounted. (We tried to get them to use a sane number
of monostables, such as 0, but couldn\'t make that one stick. They
take up less space than registers, we\'re told.)

I\'d like to do some custom mixed-signal chips. Apparently it\'s not a
totally crazy idea any more.


The power budget is going to be entertaining. ;)

A mutual friend wants me to do another driver for his electro-optical
gadget. Fast driver. How does one get rid of 60 watts on maybe half a
square inch of PCB? And not block the light?

A loop of copper tube with water running through it, or maybe a vapor
chamber heat spreader with a finned heat sink someplace nearby. Vapor
chambers are about 10x better than copper, iirc. Digikey sells them.

Charging and discharging capacitors, in principle, takes no power.

The canonical method for charging and discharging caps fast and
efficiently is to use an inductor and diode to force the charge waveform
to be half a cycle of a sine wave. That\'s how a lot of lidar laser
drivers work.

Cheers

Phil Hobbs

In theory, one can run up a parallel LC circuit and, once pumped, get
a zillion cap charge and discharge cycles for free after that.

Then, at any zero crossing, short it out for as long as you like, and
turn it loose any time after that to resume the oscillation.

Nice example of a differential equation with initial conditions.


That\'s basically the dual of the inductor + diode thing, which switches
automatically at the voltage peak.

+20V
0--LLLL-->|--*---------* 40V peak
| |
| LD Triple-stack Osram laser
few nF CCC |
CCC 0
| \\ EPC GaN FET
| 0
| |
GND GND

The Uber one I took apart a few years ago had a total inductance (around
that cap - laser - switch loop) of just under 400 pH, about half in the
source and half in the drain. (Ascertained by dorking LTspice till the
waveforms agreed with my data.)

Cheers

Phil Hobbs
Jim Thompson had an elegant CD ignition circuit that worked something
like that. It was crazy simple compared to what I used to do on
motorcycles: dc/dc converters and oil caps and SCRs and stuff.
Click to expand...

clever maybe, but needing a 5mH 5A inductor doesn\'t seem that elegant
 
On Fri, 07 Apr 2023 18:08:02 -0700, John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote:

On Fri, 7 Apr 2023 19:24:52 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2023-04-07 16:23, John Larkin wrote:
On Fri, 7 Apr 2023 13:59:33 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

So we\'re just finishing up a lidar detector chip in collaboration
with the chip design house (who does the actual circuitry, floor
plan, and polygon-pushing) and the airplane folks.

Just between us, what did that cost?

It was surprisingly reasonable--even a dedicated engineering run (20ish
wafers) was about $50k, I think, and the multiproject wafer approach (a
la MOSIS) is considerably cheaper than that. This was on an XFAB 180 nm
process with APDs and SPADs.

We\'ve been kicking around doing the guts of a laser noise canceller on a
transistor array chip--onsemi will do that for just a few $k.

We did the original proof of concept using a dead-bug prototype
with pHEMTs and CFAs and sampling diodes and stuff, which was
enough to get the program going. At this point we\'re
subcontractors to the camera folks, basically helping with the
design, doing the demo camera, and coaching everybody. (We aren\'t
head coach--maybe offensive coordinator.) ;)

It\'s been going for a couple of years, and we\'re at the point of
taping out the first of the second-generation chips.

It contains 102,400 one-shots and 106,496 Class A amplifiers,
unless I\'ve miscounted. (We tried to get them to use a sane number
of monostables, such as 0, but couldn\'t make that one stick. They
take up less space than registers, we\'re told.)

I\'d like to do some custom mixed-signal chips. Apparently it\'s not a
totally crazy idea any more.


The power budget is going to be entertaining. ;)

A mutual friend wants me to do another driver for his electro-optical
gadget. Fast driver. How does one get rid of 60 watts on maybe half a
square inch of PCB? And not block the light?

A loop of copper tube with water running through it, or maybe a vapor
chamber heat spreader with a finned heat sink someplace nearby. Vapor
chambers are about 10x better than copper, iirc. Digikey sells them.

Charging and discharging capacitors, in principle, takes no power.

The canonical method for charging and discharging caps fast and
efficiently is to use an inductor and diode to force the charge waveform
to be half a cycle of a sine wave. That\'s how a lot of lidar laser
drivers work.

Cheers

Phil Hobbs

In theory, one can run up a parallel LC circuit and, once pumped, get
a zillion cap charge and discharge cycles for free after that.

Then, at any zero crossing, short it out for as long as you like, and
turn it loose any time after that to resume the oscillation.

Nice example of a differential equation with initial conditions.
Click to expand...

Adiabatic logic with AC supply rail.

RL
 
On Friday, 7 April 2023 at 22:30:18 UTC+2, John Larkin wrote:
On Fri, 7 Apr 2023 11:21:40 -0700 (PDT), a a <mant...@gmail.com
wrote:
On Friday, 7 April 2023 at 19:59:52 UTC+2, Phil Hobbs wrote:
So we\'re just finishing up a lidar detector chip in collaboration with
the chip design house (who does the actual circuitry, floor plan, and
polygon-pushing) and the airplane folks.

We did the original proof of concept using a dead-bug prototype with
pHEMTs and CFAs and sampling diodes and stuff, which was enough to get
the program going. At this point we\'re subcontractors to the camera
folks, basically helping with the design, doing the demo camera, and
coaching everybody. (We aren\'t head coach--maybe offensive coordinator.) ;)

It\'s been going for a couple of years, and we\'re at the point of taping
out the first of the second-generation chips.

It contains 102,400 one-shots and 106,496 Class A amplifiers, unless
I\'ve miscounted. (We tried to get them to use a sane number of
monostables, such as 0, but couldn\'t make that one stick. They take up
less space than registers, we\'re told.)

The power budget is going to be entertaining. ;)

too late
lidar systems banned in public use world-wide
San Francisco is crawling with driverless cars that are decorated with
spinning gadgets.

google waymo lidar

Somebody showed us a single-chip lidar rangefinder that works at a few
inches and costs a couple of dollars. Can\'t remember who.
Click to expand...
ChatGPT-5 > ask Elon, why he has removed all his driverless cars equipped with lidar
 
On Saturday, 8 April 2023 at 03:39:55 UTC+2, a a wrote:
ChatGPT-5 > Yet one more #verySmartByHighIQaa post.
 
On Sat, 08 Apr 2023 11:31:06 -0400, legg <legg@nospam.magma.ca> wrote:

On Fri, 07 Apr 2023 18:08:02 -0700, John Larkin
jlarkin@highlandSNIPMEtechnology.com> wrote:

On Fri, 7 Apr 2023 19:24:52 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2023-04-07 16:23, John Larkin wrote:
On Fri, 7 Apr 2023 13:59:33 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

So we\'re just finishing up a lidar detector chip in collaboration
with the chip design house (who does the actual circuitry, floor
plan, and polygon-pushing) and the airplane folks.

Just between us, what did that cost?

It was surprisingly reasonable--even a dedicated engineering run (20ish
wafers) was about $50k, I think, and the multiproject wafer approach (a
la MOSIS) is considerably cheaper than that. This was on an XFAB 180 nm
process with APDs and SPADs.

We\'ve been kicking around doing the guts of a laser noise canceller on a
transistor array chip--onsemi will do that for just a few $k.

We did the original proof of concept using a dead-bug prototype
with pHEMTs and CFAs and sampling diodes and stuff, which was
enough to get the program going. At this point we\'re
subcontractors to the camera folks, basically helping with the
design, doing the demo camera, and coaching everybody. (We aren\'t
head coach--maybe offensive coordinator.) ;)

It\'s been going for a couple of years, and we\'re at the point of
taping out the first of the second-generation chips.

It contains 102,400 one-shots and 106,496 Class A amplifiers,
unless I\'ve miscounted. (We tried to get them to use a sane number
of monostables, such as 0, but couldn\'t make that one stick. They
take up less space than registers, we\'re told.)

I\'d like to do some custom mixed-signal chips. Apparently it\'s not a
totally crazy idea any more.


The power budget is going to be entertaining. ;)

A mutual friend wants me to do another driver for his electro-optical
gadget. Fast driver. How does one get rid of 60 watts on maybe half a
square inch of PCB? And not block the light?

A loop of copper tube with water running through it, or maybe a vapor
chamber heat spreader with a finned heat sink someplace nearby. Vapor
chambers are about 10x better than copper, iirc. Digikey sells them.

Charging and discharging capacitors, in principle, takes no power.

The canonical method for charging and discharging caps fast and
efficiently is to use an inductor and diode to force the charge waveform
to be half a cycle of a sine wave. That\'s how a lot of lidar laser
drivers work.

Cheers

Phil Hobbs

In theory, one can run up a parallel LC circuit and, once pumped, get
a zillion cap charge and discharge cycles for free after that.

Then, at any zero crossing, short it out for as long as you like, and
turn it loose any time after that to resume the oscillation.

Nice example of a differential equation with initial conditions.

Adiabatic logic with AC supply rail.

RL
Click to expand...

That seems to be a great theme for academic papers. Has it been done
in real life?
 
On 07-04-2023 19:59, Phil Hobbs wrote:
So we\'re just finishing up a lidar detector chip in collaboration with
the chip design house (who does the actual circuitry, floor plan, and
polygon-pushing) and the airplane folks.

We did the original proof of concept using a dead-bug prototype with
pHEMTs and CFAs and sampling diodes and stuff, which was enough to get
the program going.  At this point we\'re subcontractors to the camera
folks, basically helping with the design, doing the demo camera, and
coaching everybody.  (We aren\'t head coach--maybe offensive
coordinator.) ;)

It\'s been going for a couple of years, and we\'re at the point of taping
out the first of the second-generation chips.

It contains 102,400 one-shots and 106,496 Class A amplifiers, unless
I\'ve miscounted. (We tried to get them to use a sane number of
monostables, such as 0, but couldn\'t make that one stick.  They take up
less space than registers, we\'re told.)

The power budget is going to be entertaining. ;)
Click to expand...

Interesting.

So how does it actually work? I have heard some uses phased arrays so no
need for a spinning detector, other uses simple timing detection, but
need spinning detector.
 
On 2023-04-08 17:55, Klaus Vestergaard Kragelund wrote:
On 07-04-2023 19:59, Phil Hobbs wrote:
So we\'re just finishing up a lidar detector chip in collaboration with
the chip design house (who does the actual circuitry, floor plan, and
polygon-pushing) and the airplane folks.

We did the original proof of concept using a dead-bug prototype with
pHEMTs and CFAs and sampling diodes and stuff, which was enough to get
the program going.  At this point we\'re subcontractors to the camera
folks, basically helping with the design, doing the demo camera, and
coaching everybody.  (We aren\'t head coach--maybe offensive
coordinator.) ;)

It\'s been going for a couple of years, and we\'re at the point of
taping out the first of the second-generation chips.

It contains 102,400 one-shots and 106,496 Class A amplifiers, unless
I\'ve miscounted. (We tried to get them to use a sane number of
monostables, such as 0, but couldn\'t make that one stick.  They take
up less space than registers, we\'re told.)

The power budget is going to be entertaining. ;)


Interesting.

So how does it actually work? I have heard some uses phased arrays so no
need for a spinning detector, other uses simple timing detection, but
need spinning detector.
Click to expand...

Short bursts of very high frame rate. Details under NDA, unfortunately.

Cheers

Phil Hobbs

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

http://electrooptical.net
http://hobbs-eo.com
 
a a <manta103g@gmail.com> wrote:
On Saturday, 8 April 2023 at 03:39:55 UTC+2, a a wrote:


ChatGPT-5 > Yet one more #verySmartByHighIQaa post.
Click to expand...

Impossible. Given your postings here since you appeared, they all
indicate an individual with a serious lack of intelligence. If you
were smart, your postings here would not look like the ramblings of an
idiot. Therefore, you lack intelligence.

Previous lies by the a a troll:

Lie: http://al.howardknight.net/?ID=166924650000
http://al.howardknight.net/?ID=166924651800

Lie: http://al.howardknight.net/?ID=166935241600
http://al.howardknight.net/?ID=166935247700

Lie: http://al.howardknight.net/?ID=167224207900
http://al.howardknight.net/?ID=167224246500

Lie: http://al.howardknight.net/?ID=167245911900
http://al.howardknight.net/?ID=167245918100

Lie: http://al.howardknight.net/?ID=167595788800
http://al.howardknight.net/?ID=167595877000

Lie: http://al.howardknight.net/?ID=167890290600
http://al.howardknight.net/?ID=167890312800
 
On Sat, 8 Apr 2023 10:25:55 -0700 (PDT), a a <manta103g@gmail.com>
wrote:

On Friday, 7 April 2023 at 22:30:18 UTC+2, John Larkin wrote:
On Fri, 7 Apr 2023 11:21:40 -0700 (PDT), a a <mant...@gmail.com
wrote:
On Friday, 7 April 2023 at 19:59:52 UTC+2, Phil Hobbs wrote:
So we\'re just finishing up a lidar detector chip in collaboration with
the chip design house (who does the actual circuitry, floor plan, and
polygon-pushing) and the airplane folks.

We did the original proof of concept using a dead-bug prototype with
pHEMTs and CFAs and sampling diodes and stuff, which was enough to get
the program going. At this point we\'re subcontractors to the camera
folks, basically helping with the design, doing the demo camera, and
coaching everybody. (We aren\'t head coach--maybe offensive coordinator.) ;)

It\'s been going for a couple of years, and we\'re at the point of taping
out the first of the second-generation chips.

It contains 102,400 one-shots and 106,496 Class A amplifiers, unless
I\'ve miscounted. (We tried to get them to use a sane number of
monostables, such as 0, but couldn\'t make that one stick. They take up
less space than registers, we\'re told.)

The power budget is going to be entertaining. ;)

too late
lidar systems banned in public use world-wide
San Francisco is crawling with driverless cars that are decorated with
spinning gadgets.

google waymo lidar

Somebody showed us a single-chip lidar rangefinder that works at a few
inches and costs a couple of dollars. Can\'t remember who.
ChatGPT-5 > ask Elon, why he has removed all his driverless cars equipped with lidar
Click to expand...

I will. We\'re having lunch tomorrow.

This morning we walked in front of a Waymo that courteously stopped at
the crosswalk. There was nobody inside. Spinning gadgets all over it.
Creepy.
 
On Saturday, April 8, 2023 at 10:39:18 AM UTC-4, John Larkin wrote:

... an elegant CD ignition circuit that worked something
like that. It was crazy simple ...
Click to expand...

Umm- right out of the GE Bipolar Power Handbook from 60s-70s.
 
On Saturday, April 8, 2023 at 7:10:07 PM UTC-4, Phil Hobbs wrote:

> Short bursts of very high frame rate. Details under NDA, unfortunately.

Careful. I can glean what\'s going on just by mention of \"frames.\"

I thought that 100,000 monostables was kinda small for your application. 320 x 320 = 102,400


Cheers

Phil Hobbs

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

http://electrooptical.net
http://hobbs-eo.com
Click to expand...
 
On Sun, 9 Apr 2023 03:03:25 -0700 (PDT), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

On Saturday, April 8, 2023 at 10:39:18?AM UTC-4, John Larkin wrote:

... an elegant CD ignition circuit that worked something
like that. It was crazy simple ...

Umm- right out of the GE Bipolar Power Handbook from 60s-70s.
Click to expand...

I have a lot of cool old data books, but not that one. I\'ll hunt for
one.
 
On Sat, 8 Apr 2023 19:09:50 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2023-04-08 17:55, Klaus Vestergaard Kragelund wrote:
On 07-04-2023 19:59, Phil Hobbs wrote:
So we\'re just finishing up a lidar detector chip in collaboration with
the chip design house (who does the actual circuitry, floor plan, and
polygon-pushing) and the airplane folks.

We did the original proof of concept using a dead-bug prototype with
pHEMTs and CFAs and sampling diodes and stuff, which was enough to get
the program going.  At this point we\'re subcontractors to the camera
folks, basically helping with the design, doing the demo camera, and
coaching everybody.  (We aren\'t head coach--maybe offensive
coordinator.) ;)

It\'s been going for a couple of years, and we\'re at the point of
taping out the first of the second-generation chips.

It contains 102,400 one-shots and 106,496 Class A amplifiers, unless
I\'ve miscounted. (We tried to get them to use a sane number of
monostables, such as 0, but couldn\'t make that one stick.  They take
up less space than registers, we\'re told.)

The power budget is going to be entertaining. ;)


Interesting.

So how does it actually work? I have heard some uses phased arrays so no
need for a spinning detector, other uses simple timing detection, but
need spinning detector.

Short bursts of very high frame rate. Details under NDA, unfortunately.

Cheers

Phil Hobbs
Click to expand...

Do the one-shots store the hits until you can read them all out?
 
On Sunday, April 9, 2023 at 10:37:34 AM UTC-4, John Larkin wrote:
On Sun, 9 Apr 2023 03:03:25 -0700 (PDT), Fred Bloggs
bloggs.fred...@gmail.com> wrote:
On Saturday, April 8, 2023 at 10:39:18?AM UTC-4, John Larkin wrote:

... an elegant CD ignition circuit that worked something
like that. It was crazy simple ...

Umm- right out of the GE Bipolar Power Handbook from 60s-70s.
I have a lot of cool old data books, but not that one. I\'ll hunt for
one.
Click to expand...

My mistake, it was RCA. See Automotive Applications starting page 243. Be warned- it is from a time when engineers did math:

http://www.rsp-italy.it/Electronics/Databooks/RCA/_contents/RCA%20Power%20Transistor%20Applications%20PTA400%201983.pdf

Not sure if it\'s the exact one I had in mind, which I\'m sure pre-dated 1983..
 
On Sun, 9 Apr 2023 09:38:58 -0700 (PDT), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

On Sunday, April 9, 2023 at 10:37:34?AM UTC-4, John Larkin wrote:
On Sun, 9 Apr 2023 03:03:25 -0700 (PDT), Fred Bloggs
bloggs.fred...@gmail.com> wrote:
On Saturday, April 8, 2023 at 10:39:18?AM UTC-4, John Larkin wrote:

... an elegant CD ignition circuit that worked something
like that. It was crazy simple ...

Umm- right out of the GE Bipolar Power Handbook from 60s-70s.
I have a lot of cool old data books, but not that one. I\'ll hunt for
one.

My mistake, it was RCA. See Automotive Applications starting page 243. Be warned- it is from a time when engineers did math:

http://www.rsp-italy.it/Electronics/Databooks/RCA/_contents/RCA%20Power%20Transistor%20Applications%20PTA400%201983.pdf

Not sure if it\'s the exact one I had in mind, which I\'m sure pre-dated 1983.
Click to expand...

Thanks. Some of those old data books are worth reading. My GE SCR
Manual has some interesting topologies.

Engineers had to do more math when they didn\'t have Spice.

I was just talking to a physicist who works for EPRI researching water
flow all over the world. He paid for dinner at the Anchor Oyster Bar,
which is fabulous.

He says he does snippets of calculus to project river flows. I noted
that calculus is hard and nonlinear calculus is about impossible, so
we EEs simulate. He pretty much agreed, but he doesn\'t have anything
like LT Spice. Circuits are easy to simulate compared to clouds and
rivers.

Apparently EE students generally take three semisters of calculus. And
probably never use it. Seems a waste. I took Honors Math at Tulane and
we did crazy abstract-math stuff. I think I got about a week of
calculus.
 
On Sunday, April 9, 2023 at 12:57:45 PM UTC-4, John Larkin wrote:
On Sun, 9 Apr 2023 09:38:58 -0700 (PDT), Fred Bloggs
bloggs.fred...@gmail.com> wrote:
On Sunday, April 9, 2023 at 10:37:34?AM UTC-4, John Larkin wrote:
On Sun, 9 Apr 2023 03:03:25 -0700 (PDT), Fred Bloggs
bloggs.fred...@gmail.com> wrote:
On Saturday, April 8, 2023 at 10:39:18?AM UTC-4, John Larkin wrote:

... an elegant CD ignition circuit that worked something
like that. It was crazy simple ...

Umm- right out of the GE Bipolar Power Handbook from 60s-70s.
I have a lot of cool old data books, but not that one. I\'ll hunt for
one.

My mistake, it was RCA. See Automotive Applications starting page 243. Be warned- it is from a time when engineers did math:

http://www.rsp-italy.it/Electronics/Databooks/RCA/_contents/RCA%20Power%20Transistor%20Applications%20PTA400%201983.pdf

Not sure if it\'s the exact one I had in mind, which I\'m sure pre-dated 1983.
Thanks. Some of those old data books are worth reading. My GE SCR
Manual has some interesting topologies.

Engineers had to do more math when they didn\'t have Spice.

I was just talking to a physicist who works for EPRI researching water
flow all over the world. He paid for dinner at the Anchor Oyster Bar,
which is fabulous.

He says he does snippets of calculus to project river flows. I noted
that calculus is hard and nonlinear calculus is about impossible, so
we EEs simulate. He pretty much agreed, but he doesn\'t have anything
like LT Spice. Circuits are easy to simulate compared to clouds and
rivers.
Click to expand...

They have plenty of MATCAD and MATLAB type programs to help them do the grunge work. Pencil and paper are just to flesh out ideas.

Alternative use of SPICE to do other forms of simulation is weak. There are some SPICE that will compute a symbolic circuit transfer function in Laplace notation, like TINA, and that\'s useful.

Apparently EE students generally take three semisters of calculus.

And
probably never use it. Seems a waste. I took Honors Math at Tulane and
we did crazy abstract-math stuff. I think I got about a week of
calculus.
Click to expand...
 
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