Thanks Dave.

I would not have gotten this without the help of the Cleveland
Browns!!  Well, not the answer, but that I watched the whole
Browns/Jets game last night - Adele is from Akron and the rest of her
family are Browns fans (and will be all over Facebook today).   I just
dialed up TechNet before bedtime, and there was the Friday question -
just before midnight EDT.

Your question - why in photodetectors?  I think you started on it with
your comment "Thallium sulfide's electrical conductivity changes with
exposure to infrared light"   So, my chemical engineering guess is
that you put the thallium sulfide detector in a bridge circuit.  When
IR hits it, the bridge circuit amplifies the change in
resistance/current - and presto - you get a detectable change.  You
know chemical engineering - more water flowing thru the pipe, more
pressure in the pipe, the level of the water in the tank rises - one
of those electrical thingies, easily described in chemical engineering
terms.

This week, I need different tasks from Clumpy and Kloumpios.  I think
you said both can drive tractors - which one is best?  Or, which one
can drive one of those wonderful red International tractors instead of
the worthless green John Deeres.  OOPS, John Deere does a lot of
electronics and is a big wheel in IPC.  Restated - which one can drive
a crummy old red International without electronics with a 6 volt
battery instead of one of those marvelous new John Deeres?  That one
will be disking, spreading fertilizer, and planting seed for the hay
crop on our farm next summer.

The agriculturally challenged one will be helping me with reports on
"the status of the US Defense Electronics Industry in support of
Paragraph 845 of the 2019 Defense Authorization Act.  All three -
Defense in DC, Executive Agent  at Navy Crane, and IPC are working
together on a report due in January 2019.   Recently retired from
SAIC/Crane - I am now playing on the IPC team.

More when I see all of you at SMTAI/IPC in Rosemont.

Denny Fritz
Fritz Consulting.




On 9/21/18, David Hillman <[log in to unmask]> wrote:
>  The Question:
> A compound of this element was the primary ingredient in rat poison until a
> 1972 Executive Presidential Order banned its commercial use. This element
> and its compounds are extremely toxic to everything and it was once
> considered the "poison of choice" by assassins. Nearly 70% of this
> element's commercial use is in the electronics industry for making
> photoresistors and selenium rectifiers. One of the element's nuclides is
> still used in stress tests for coronary artery disease risk assessment.
> What
> element is being described?
>
> The Answer:
> The element is Thallium (Tl). Thallium derives its name from the Greek word
> "thallos" which means "green twig or young shoot". Under spectroscopic
> analysis, thallium produces a bright green line. Thallium (radioactive
> isotope thallium-201, with a half-life of 73 hours) had wide spread use in
> nuclear cardiography until the adoption and widespread application of
> technetium-99m in nuclear medicine. Thallium sulfide's electrical
> conductivity changes with exposure to infrared light therefore making this
> compound useful in photoresistors and doping selenium semiconductors with
> thallium improves their performance.
>
>
> The winner of the quiz is Denny Fritz and he will get the services of
> Clumpy
> and Kloumpios for the week.
>
>
> I have never heard of the use of Tl in photoresistors - can anyone shed
> some light (pun intended) on how much they are used in today's electronics?
>
>
> So far Clumpy and Kloumpios have done the following:
>
> Past Quiz winners/tasks:
> Week 1 Ravinder Ajmani, Western Digital
> Week 1 Ron Feyereisen, SigmaTron Intl.
> Week 2 Louis Hart, Compunetics
> Week 3 Mark Kostinovsky, Schlumberger Ltd.
> Week 3 John Burke
> Week 4 Drew Meyer, Benchmark Electronics
> Week 5 No Winner - no correct responses!
> Week 6 Bhanu Sood, NASA
> Week 7 Keith Calhoun, Sopark Corp
> Week 7 Ian Fox, Rolls Royce
> Week 8 Leland Woodall
> Week 8 David Bealer, SMT
> Week 9 Tom Carroll, Boeing
> Week 10 Louis Hart, Compunetics
> Week 11 Tom Carroll, Boeing
> Week 11 Scott Decker, UTAS
> Week 12 Matthias Mansfeld, Mansfeld Elektronik PCB Design and Assembly
> Week 13 No Quiz,
> Week 14 Matthias Mansfeld, Mansfeld Elektronik PCB Design and Assembly
> Week 15 Bhanu Sood, NASA
> Week 16 John Maxwell
> Week 17 Leland Woodall
> Week 18 Leland Woodall
> Week 19 Tom Carroll, Boeing
> Week 20 Robert Kondner
> Week 21 Tom Brendlinger, ClearMotion Inc.
> Week 22 Carl Van Wormer, Cipher Engineering LCC
> Week 23 Juliano Ribeiro, DATACOM
> Week 24 Gerry Gagnon, FLIR Commercial Systems
> Week 25 Graham Collins, Sunsel Systems
> Week 26 Joyce Koo, IPC International
> Week 26 Todd MacFadden, Bose
> Week 27 Bhanu Sood, NASA
> Week 28 Leland Woodall
> Week 29 Mordechai Kirshenbaum
> Week 30 Leland Woodall
> Week 31 Leland Woodall
> Week 32 Steve Gregory
> Week 33 Leland Woodall
> Week 34 Jerry Dengler, Pergamon Corp
> Week 35 Frank Kimmey, VeriFone Inc
> Week 36 Graham Collins, Sunsel Systems
> Week 37 Richard "Dean" Stadem
> Week 38 Leland Woodall
> Week 38 Tom Carroll
> Week 39 Matthias Mansfeld, Mansfeld Elektronik PCB Design and Assembly
> Week 40 Leland Woodall
> Week 41 Tom Carroll
> Week 42 Matthias Mansfeld, Mansfeld Elektronik PCB Design and Assembly
> Week 43 Joyce Koo
> Week 44 Russell Kido, Practical Components
> Week 45 Leland Woodall
> Week 45 Frank Kimmey, VeriFone Inc
> Week 46 Ian Fox, Rolls-Royce Control Systems
> Week 47 Fred Cox, Bluering Stencils
> Week 48 Tom Carroll, Boeing
> Week 49 Todd MacFadden, Bose
> Week 49 Leland Woodall
> Week 50 Russell Kido, Practical Components
> Week 51 Ravinder Ajmani, Western Digital
> Week 52 Leland Woodall
> Week 53 Scott Decker, UTAS
> Week 54 Leland Woodall
> Week 55 Tom Carroll, Boeing
> Week 56 Mordechai Kirshenbaum
> Week 57 Steve Herring, Pennatronics Corp
> Week 58 Leland Woodall
> Week 59 Drew Meyer, Benchmark
> Week 60 Leland Woodall
> Week 61 Matthias Mansfeld, Mansfeld Elektronik PCB Design and Assembly
> Week 62 Leland Woodall!
> Week 63 Matthias Mansfeld, Mansfeld Elektronik PCB Design and Assembly
> Week 63 Tom Carroll, Boeing
> Week 63 Tom Granat
> Week 64 George Wenger
> Week 65  Frank Kimmey, VeriFone Inc.
> Week 66  Jerry Dengler, Pergamon Corp
> Week 66  Leland Woodall
> Week 67  Eray Canli,  ANDAR Electromechanical Systems
> Week 68  James Head
>
> Week 69  Mordechai Kirshenbaum
> - but I don't want the brothers to travel so far away (they already had
> been in Israel several months ago)...so they get the week off!
>
> Week 70 Doug Pauls, Rockwell Collins
> - The boys will be glad to be home and see the wives and family for a long
> weekend.  They can help me with an 86000 lines of data statistical
> analysis, but then they get the weekend off.
>
> Week 71  Eray Canli,  ANDAR Electromechanical Systems
> - Boys can leave as soon as we finish forging three Damascus steel knives
> together, from a Vanadium doped leaf spring of an old truck...and in
> addition to their knives, I'll buy them cold beer for their effort and
> sweat!
>
> Week 72  Russell Kido, Practical Components
> - I'll have the boys check the Saber kits.  I'm staying as far away as
> possible!! They can help me situate some new mattresses and since they have
> some 'hops' and can 'sky' for being little guys, they can continue to teach
> my daughter their skills in jumping, rebounding and shooting.  They can
> also drive me from my glaucoma test and then soak up some rays.
>
> Week 73 Denny Friz
> - assisted with ????
>
>
>
> I hope everyone has a awesome week!
> Dave Hillman
> Rockwell Collins
> [log in to unmask]
>


-- 
Denny Fritz
Consultant
812 584 2687