#1692

[@zeno2712]

Sometimes what you got from Bob's excellent columns was more about how he approached problems; how he helped engineers understand the things you weren't taught in university; how he was firmly grounded in the practicalities of designing circuits and understanding how and why they behaved the way they did - or the way they didn't behave. I was privileged to meet Bob once on his trip to the UK as he toured some electronics manufacturers. His beard and Volkswagon Beetle were legendary! As he said in one of his columns, you never saw a Beetle at the side of the road, broken down.

[@rockpadstudios]

I wish I could have worked in the electronics industry with people like Bob.

[@mikebond6328]

The old beetles were reliable but not very safe.

[@craigpierce7996]

I have the original National Semi Analog Applications book. And all the Linear Tech application books when Bob jumped ship from National. It was a great move for Bob where he worked with Jim at Linear. Those two were magic together!! Jim's speciality was switching regulators, where I learned most of what I know and have applied. The two had a great phrase that I still use today: CREAKY DISCRETE! Describing circuits built proto style, with parts hanging up in the air soldered to stuff by their leads. They where recipes for Lab Queens, a design that only works in the lab. Got a few of those, too! 😁 I seriously miss those days and the buzz that was all around Silicon Valley. I am blessed to have experienced it!

[@alanholt6535]

You had me at Bob Pease.....

[@drtidrow]

Bob Pease is a legend among analog EEs. 😎

[@Peter_S_]

What's all this measurement stuff, anyhow? R.I.P. Bob Pease and Jim Williams; two giants of the Valley.

[@craigpierce7996]

Those were great articles! I always knew I was going to learn something when they came out.

[@dennisfahey2379]

My favorite Bob Pease article had him with his logic analyzer hooked up to his circuit with two probes clipped to his beard. What a character. RIP Bob.

[@2oqp577]

Had the honor to meet Bob Pease in Montreal, 24 years ago. Great guy. RIP.

[@KeritechElectronics]

"Great Scott! Two femtoamps!" That's a nice chip-of-a-day not really labeled chip-of-a-day. And a nice though long-ish cap testing method. Fun fact, air wiring has been done on a Meratronik V640 (sold on Canadian market as Conway Masteranger 639). There's a teflon-insulated terminal on the input pin of the HLY7006R hybrid opamp, to prevent the PCB resistance and capacitance from disturbing the measurement. The sensitive input circuitry as well as the range switch are shielded with sheet metal boxes.

[@Enigma758]

"Pease porridge" was the name of his column. He died in a car crash driving his beetle home from the memorial service of Jim Williams.

[@mikebond6328]

My first car was a beatle. Hit a patch of black ice, did a 180, and rolled 3 times down a bank by a river when I was 16. The car landed on its top. The driver’s door was open and crushed against the front fender. My left shoe had come off and my left foot was broken. I’m pretty sure my left foot caught on the clutch pedal and kept me from being thrown out. Also broke my tailbone. Haven’t been able to sit still since.

[@Vintage_USA_Tech]

It was a very sad time in electronics history to lose 2 of the greatest analog electronics engineers so close together, I have the book Analog Circuit Design edited by Jim Williams and it has The Story of the P2 (The first Successful Solid State Op-Amp with Picoampere Input Currents) written by Bob Pease, it is a great read its almost like hanging out with them and listing to them tell their story's I highly recommend it.

[@Enigma758]

@@Vintage_USA_Tech Thanks, I'll definitely check that out.

[@JxH]

Yep, sad few weeks. To quote Wikipedia, "Pease was killed in the [relatively minor] crash of his 1969 Volkswagen Beetle, on June 18, 2011. He was leaving a gathering in memory of Jim Williams, who was another well-known analog circuit designer, a technical author, and a renowned staff engineer working at Linear Technology. Pease was 70 years old..."

[@ats89117]

Ironically, he was the author of the book: "How to Drive Into Accidents ... and How Not To". Unfortunately, the beetle with all of its charm, was a very unsafe car...

[@gary6449]

I had the distinct honor of meeting Bob Pease in person at a local electronics distributor's trade show here in Phoenix, AZ in ~2004. Quite the character he was ! The fingers of his right hand were all bandaged up from shaking so many fans' hands !

[@charlesspringer4709]

Cool. Bob was such a helpful guy. I was living in Palo Alto working on some ideas of my own and needed a really good low noise long period integrator and I called him up. I recall he recommended that same cap as in the "stuff" piece. I talked with him a number of times. Hearing of his demise on the way home from Jim Williams' funeral was the most unreal am-I-dreaming experience I have ever had. Seat-belt denier!

[@glasslinger]

I just dismantled a gamma spectrometer and the supply circuit for the germanium detector used "air wiring." The resistors in the circuit were "open circuit" as far as my 6 digit DVM read. By using an insulation tester they tested at 2 gigaohms each! I'm guessing conduction on a circuit board would taint the reading so they used the air wiring. Also, the housing with the electronics board was O ring sealed and had a valve connection to fill the compartment with dry gas. No way to operate the spectrometer since it needs liquid nitrogen so dismantling it for knowledge was its fate.

[@ke9tv]

Those detectors go bad if they're taken out of liquid nitrogen, with about the same time constant as fish. So the detector was trash anyway.

[@glasslinger]

@@ke9tv That is nonsense! But I do agree the unit was "trash" since without the control electronics plus having to get the nitrogen every time you want to use it there is no way to be practical. The detector crystal is in good condition though. (for whatever good it will do!)

[@ke9tv]

@@glasslinger Depends on the crystal. High-purity germanium is stable, so are CdTe, CZT, NaI, HgI2. SiLi most emphatically is not, and GeLi is even worse - and I suspect strongly that the crystal in question was GeLi. Back in the day, that was the commonest X-ray/gamma detector that needed liquid nitrogen. (And it's still got impressive resolution of photon energies, so it still has its uses.) When I was in grad school (more decades ago than I care to admit), some of my colleagues never got to take a vacation because those cryostats had to be kept filled at all times, even when they weren't taking data.

[@glasslinger]

@@ke9tv Maybe I can make a pendent out of it. :)

[@d.jeffdionne]

A way to get close to air wires in 'production' is teflon terminal standoffs. You can see those in e.g. the input and integrator circuits of many bench meters, probably that HP34401A. Hmmm. I think I'll build a simple unity gain buffer probe with that LMC662 part for poking around high impedance low frequency circuits...

[@paulfasolo8552]

Bob Pease was a wonderful man with insightful comments regarding all facets of electronics!

[@InssiAjaton]

Not limited to only electronics. I remember he covered all kinds of human life topics, such as not needing weight scale or some thickness measuring devices (calipers). He just memorized for example American coin weights and used them as a reference. Same, he memorized common office paper thickness and could then use his finger touch to compare the unknown to a stack of the paper sheets. He also figured out a roof leakage location that was nowhere near either the smoke stack nor the tell tale spot on the ceiling. Also, it did not appear during the rain. So, the water was delayed on its way. And that was his clue, the water was traveling a long distance on a wooden beam, until it finally dropped down. And of course, he calculated everything he needed in his head.

[@ebrombaugh]

I met Bob at Wescon back in the mid 90s. IIRC he passed away in a car accident coming home from Jim Williams funeral - so sad.

[@lohikarhu734]

In the early days of Bob's writing, 1974, for me, we called it "point-to-midair wiring", and one could also use wire-wrap to get the same effects.

[@richardl6751]

At 3:23 Two femtoamps! Wow! Since a Coulomb is 6.2415 x 10^18 electrons, two femtoamps would be 12 electrons per second current flow.

[@chriswalford4161]

That’s nearly slow enough to see them!

[@JxH]

Once upon a time, I wrote a letter to Bob Pease, about some technical detail. He wrote back, but he wrote back on the chopped-up and trimmed letter that I had mailed to him! He chopped it up perhaps so that it was less weight to mail back (international). What a wonderful and lovely 'mad scientist' he was. I was heart broken when he was killed in what should have been a walk-away accident. Classic cars are nice, but can be a death trap; they're not '5 star' safety.

[@IMSAIGuy]

bob thinking, "I'll chop this up so years later he will still be wondering why"

[@carlthome5692]

I remember seeing Bob Pease at Fry's in Sunnyvale for a book signing back in the early 90's.

[@lohikarhu734]

Bob's Beetle killed him, in the end...if i remember correctly, on his way home from Jim Williams' funeral...a relatively trivial crash, but those old beetles had Zero safety features, and Bob might have been the kind to not wear a seat belt (open to correction on that) Bob had a public persona of "jolly", but I was near his office on a visit to NSC (I had responsibility for designand design-in, of, let's say, quite a few wafer starts), and Bob was decidedly not so friendly, or jolly, as he appeared at seminars...but, hey, we probably all have a bad day from time to time. Indeed, some of my first 'serious' electronic reading was "Floobydust", and the huge "Linear Applications Manual" it felt quite cool, years later, to be working directly with Grass Valley and Oulu design teams, actually driving new IC's into the market!

[@capriracer351]

The earliest mention I have seen of Bob Pease was in a 1968? issue of Analog Devices' magazine, "Analog Dialog" He most likely would have been working for Philbrick at the time. He sent in a letter to the editor taunting the guys at Analog Devices about something, I can't remember what. He was quite the character and definitely missed. EDIT: I looked up the .pdf. The issue was Volume 4, No.1. June 1970. Read his letter and the response. They are hilarious. Bob got his taunt thrown right back in his face, Lol.

[@kinanlaham744]

LMC662 has 2 fA input bias current. Impressive!

[@theoldbigmoose]

I sure miss Bob Pease

[@8-bitbitsa821]

I worked with numerous people in the semiconductor industry in Silicon Valley, they knew Bob… they all spoke good things about Bob when at Nat Semi… sorry I missed him, would have liked to have met him 👍🏻

[@carl-l3z]

Got his books and a bunch of his app notes.

[@d614gakadoug9]

I get the impression, perhaps incorrect and even grossly so, that a lot of hobbyists these days don't read ap notes (I'm old _ap_ is spelled with one _p_ ) and instead rely on videos. That is a big mistake. There is vast body of knowledge to be had from ap notes, including those from many years ago. There are also many excellent, if somewhat expensive, books from people like Bob Pease and Jim Williams. Bob did harbor some perverse ideas about computers and simulations.He'd never dream of using an oscilloscope without being sure the probes were properly compensated or without the understanding of how probing loaded and changed the behavior of circuits, yet he'd get all bent out of shape because of his own failure to attend to the details of simulation, blaming the computer for his shortcomings.

[@1shARyn3]

so, if my calcs are right, a 2 fA toll over 24 hours on a 1uF cap is a loss of 172.8 uV? That is impressive (his leakage is almost 16x the toll loss)!!

[@SerialNumber-jm1sg]

Hi! Very nice! Best regards from Russia

[@lohikarhu734]

Bob mentioned floating the DVM to 8 V, or so, I guess to reduce the capacitance of the DVM leads and input from "stealing" some charge into the 10-20 pF (about)...

[@byterock]

Good old Bob, winner of 'The Messiest Desk of the Year' 23 years running ;)

[@drtidrow]

First, second, _and_ third place! 🤣🤣🤣

[@Mr.Leeroy]

When I needed to measure GOhm resistors, I found myself OPA2376, probably cheaper: 0.2 - 10 pA input bias current as well as 5 - 25 uV input offset voltage, quite a bit better that ones in the video at 1 - 6.3 mV. Also Ib for LMC662 range is 0.002 - **4** pA, so...

[@andymouse]

The Max4239 is my go to, nice part Dave Jones (EEVBlog) used them in his 'Micro Current' product thats how I found them.

[@Mr.Leeroy]

@@andymouse It could work, but unfortunately Maxim did not test nor guarantee its bias current _range_

[@andymouse]

Oh Interesting ! yeah works fine and Thanks ! :)@@Mr.Leeroy

[@staryduren]

without box there could be some interesting photo effects on PCB surface, observed years ago in I-U converter with 2.2 GΩ feedback resistor

[@galileo_rs]

Mr Carlson capacitor leakage tester is an interesting simple project.

[@radarmusen]

Find it interesting when he told about bipolar caps shielding there has to be at ground so it not pick noise up. Suddenly they also are important to fit correctly.

[@marktryer315]

Just saw a video of his office and washed out yellow beetle, he had so documents and boxes he had to force the chair to turn at the desk.

[@andymouse]

Fascinating !....cheers.

[@antiquephotographyodedlevy]

Thanks for sharing, I am thinking about making a high resistance measuring adaptor to regular multimeter with this op amp that will be able to mesure 1G ohm do you think it is possible?

[@IMSAIGuy]

R=V/I so yes. just pick values that work.

[@henrikstenlund5385]

Some leakage will come from air currents, both ions and other leakage modes.

[@Snowsea-gs4wu]

Hi just checked Bob’s book on analog circuits and it goes for a little less than USD50!

[@matambale]

I can detect the Pease Influence in the videos you make. Just need a beard and a Beetle...

[@IMSAIGuy]

my first car was beat up '71 beetle

[@nagelay1613]

❤❤❤❤❤❤

[@leosbagoftricks3732]

Bob is God.

[@soulrobotics]

3 days, huh?... imagine you have to test 10 capacitors...

[@jimmuehlberg2153]

Just build ten circuits! Total cost: ~$20!

[@dimitarnikolov3527]

I would wear gloves if I'm doing this precise measurements. The grease from your fingers could increase the femtoamps slightly

[@drtidrow]

Scrubbing the circuit board and rinsing with deionized water is likely helpful as well.

[@coldfinger459sub0]

Funny, this video was just recommended to me when two days ago I measured some capacitors that I charged up to 50 V their maximum over two years ago. They were wrapped in bubble wrap and stored in a box and I just measured them and they all still have 10 V charge after two years. These were electrolytic capacitors for a class A amplifier is what there to be used on. On the power supply.