Widlar's Early Treatise on Semiconductors

Widlar's Early Treatise on Semiconductors, so large a file to E-mail, I put it up on my website so you can download it...

...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
 Click to see the full signature
Reply to
Jim Thompson
Loading thread data ...

Note fig 1.4, the military convention for current flow!

--
John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
 Click to see the full signature
Reply to
John Larkin

That's not the "military" convention, that's the "physics" convention. Ask Hobbs ;-) ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
 Click to see the full signature
Reply to
Jim Thompson

The US military, and a couple of the Heald-class trade schools, taught electron-flow convention. That messed up a lot of people.

I took physics in college, and EE courses simultaneously, and both used the conventional current flow sign.

--
John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
 Click to see the full signature
Reply to
John Larkin

...Jim Thompson

Ho humm... it's current. Period. Current means charge flow. Charge flow flow don't make sense.

Kevin Aylward

formatting link
formatting link
- SuperSpice

Reply to
Kevin Aylward

Yay, Kevin, good comment!

Reply to
John S

At MIT, in the Physics department, I took only Classical Mechanics and Quantum Physics.

Electromagnetics was under the EE department, as were Germanium transistors ;-)

Advanced Mechanics (and Strength of Materials) I took under the ME department (I was in the Honors EE Program and had to take "electives" as if I were majoring in that department).

And lots of annoying Chemistry classes :-(

But great fun with 5 semesters of Calculus thru tensors. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
 Click to see the full signature
Reply to
Jim Thompson

Nah, there's current density, current crowding, current hogging, displacement current, and all sorts of things that aren't just current.

Displacement current especially--that exists in a charge-free vacuum, so "current" ain't just charge flow.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
 Click to see the full signature
Reply to
Phil Hobbs

Only 5 semesters of math? What were you, the layout guy? ;)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
 Click to see the full signature
Reply to
Phil Hobbs

We had two semesters of general physics, taught by the Physics department. It was classical mechanics and some electricity, up to the point of solving simple DC circuits.

Yeah, chemistry was horrible.

I had about a week of calculus. Our PhD math instructor was gaga for set theory, so spend most of the time on that. He covered calculus as quick as he could. Our EE Electromagnetics instructor was brilliant, lazy, and had such a thick Japanese accent that nobody could understand him. He was also our EE lab instructor; he'd leave after 5 minutes, we'd leave after 10, and we faked all the lab reports in one all-nighter at the end of the semester. If you know enough to fake the lab data, you know enough.

That's when I started doing system simulations, first on an HP9100 programmable calculator, then a PDP-8, then a PDP-11. My first close-loop controller design was for a 32,000 HP steamship, and it behaved just like the sim. The loop was wildly nonlinear, not suited at all to analytical solutions.

--
John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
 Click to see the full signature
Reply to
John Larkin
[snip]

Absolutely! At MIT we called it "dry lab" ;-) ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
 Click to see the full signature
Reply to
Jim Thompson

I developed a technique for sloppy slide-rule slipping, that made beautiful curves with nice experimental point scatter. Looked great.

The few guys who did stay and do the work didn't get such good grades. My slide rule worked better than the klunky lab equipment.

--
John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
 Click to see the full signature
Reply to
John Larkin

My current flows. Maybe yours just pools up on the floor or something.

--
John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
 Click to see the full signature
Reply to
John Larkin

Well, you also have to know enough to get the wrong answer, by the right amount, particularly in chem labs.

Same at UIUC. I only did it for chem, though. Hopeless courses with even less useful labs, intended only to waste *loads* of time and thin the herd. Physics wasn't much different. It was only next to useless (third semester was absurd).

Reply to
krw

Wow. No wonder you guys like simulation so much. ;)

The lab courses I was in (three physics, one chemistry, and one astronomy at UBC and one in physics at Stanford) were taught well, had profs that hung around, TAs that knew your name and saw how you worked, and (usually) a long-serving engineering technician who would answer questions, keep the apparatus working, and take no BS whatsoever. (The guy at UBC Physics was Wolf Breuer, a great man in his way, and the one at Stanford was Eric Gustafson, who ran out of money as a grad student and had to take the lab job, but later finished his Ph.D. and did some good work elsewhere, iirc.)

Slacking off in the lab would have attracted immediate and very unfavourable notice in either place.

I hope and expect that you guys are mostly just bragging, but either way, it's entirely misguided.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
 Click to see the full signature
Reply to
Phil Hobbs

No, I really cut the EE labs and faked the reports. I'd done far more sophisticated stuff when I was in Junior High school.

In one case, the task was to plot the frequency response of a class A tube amp. I got the curve right because I didn't do the experiment. The people who did do it got a flat DC-to-daylight curve, because the shared lab B+ supply had 50 volts p-p of ripple.

I did stay for the Electrical Machinery labs, big motors and generators and transformers and stuff. That was fun.

--
John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
 Click to see the full signature
Reply to
John Larkin

As you say, if you know the material, fudging the data points is trivial ;-) ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
 Click to see the full signature
Reply to
Jim Thompson

[snip]

Yep. I liked machine lab as well. And testing the premise that disconnecting the field would cause run-away... it did >:-} ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
 Click to see the full signature
Reply to
Jim Thompson

Me? Like simulation? I only use it for things like series filters and a few other things. I can't stand the models board level designers are forced to use, so don't trust anything but "ideal" components. At least I know what I'm simulating.

The TAs in chemistry and physics weren't so bad but the classes, and in particular, the labs were horrible. That's on the full prof running the show, not on the poor droid carrying out the orders.

Who said anything about slacking off? The labs, particularly the chem labs, just didn't work and, even with all of the time they wasted (under penalty of the grade) weren't long enough to finish the project it *anything* went wrong.

With chem and physics? Not a chance. The courses were really bad (and got worse with each one. The third semester of physics was optics AND quantum. The curve was bimodal with >40% between 90 and

100, and >40%
Reply to
krw

Sorry, but that's the sort of argument I expect from the climate crooks at East Anglia. Fudging data is a big no-no.

Dunno about the course. That's the prof's responsibility. How we handle it is ours.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
 Click to see the full signature
Reply to
Phil Hobbs

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.