A good digital oscilloscope?
in [Design]
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From: Martin Brown on 15 Dec 2009 18:01 John Larkin wrote: > On 10 Dec 2009 17:26:14 GMT, Robert Latest <boblatest(a)yahoo.com> > wrote: > >> Joerg wrote: >> >>> Back in those days watch dials would be readable all night, not nearly >>> have that much decay. That is no longer the case, no matter what fancy >>> material they use. >> I wonder if the phosphorescence of that radium compound has anything to >> do with the radium's radioactivity. Maybe the radioactivity helps to get >> the energy into or back out of the long-term storage states. >> >> robert The radioactivity is the source of the power generating the light. > > Of course it does. Radium phosphors will glow in the dark for > centuries. That's what the radium is for. Although the radium remains radioactive for centuries the level of damage it inflicts on the zinc sulphide phosphors used in the old luminous paint formulations mean that they are quite faint now. http://www.aia.net/pressroom/nrcnews.html An old WWII era radium dial watch was hot enough to set off personal monitoring alarms in some nuclear sites. > Tritium too, except its > half-life is around 12 years. > > John Phosphor laden tubes with tritium in were used as emergency lights of last resort in the UK ca 1970's. Now there are tritiated plastics serving a similar purpose as emergency lights but at a lower activity level. http://en.wikipedia.org/wiki/Beta_light Converting LCD digital watches with tritiated luminous fishing floats was popular when I was at university. The phosphor survives pretty well against 18.6keV electrons and just emits light. Regards, Martin Brown
From: krw on 15 Dec 2009 18:44 On Tue, 15 Dec 2009 16:46:37 -0500, Spehro Pefhany <speffSNIP(a)interlogDOTyou.knowwhat> wrote: >On 15 Dec 2009 21:10:28 GMT, Robert Latest <boblatest(a)yahoo.com> >wrote: > >>Jan Panteltje wrote: >>> On a sunny day (10 Dec 2009 17:34:26 GMT) it happened Robert Latest >>><boblatest(a)yahoo.com> wrote in <7ocpp2F3p9ht0U2(a)mid.uni-berlin.de>: >>> >>>>Jan Panteltje wrote: >>>>> 'Spiritus' is 85% Ethanol, and 3% Methanol, plus a horribe smell and >>>>> taste added... Vodka is expensive, and only 40%, heavely taxed here. >>>> >>>>I don't think there's methanol in it. >>>> >>>>robert >>> >>> Spiritus has it written on the bottle, contains: >>> 85 % Ethanol >>> max 3 % Methanol. >> >>That's integesting. I need to check, but I think in Germany "Spritus" is >>just alcohol plus some non-toxic but extremely bitter-tasting additives. >>OK, the German Wikipedia confirms this. No Methanol. >> >>robert > >Denaturing can use different additives. Maybe it's illegal to poison >people in Germany. I think you'll find that denatured alcohol doesn't contain methanol in the US anymore either. It is supposed to be cut with something that the stomach can't tolerate, though.
From: krw on 15 Dec 2009 18:48 On Tue, 15 Dec 2009 09:34:02 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon(a)My-Web-Site.com/Snicker> wrote: >On Tue, 15 Dec 2009 08:02:56 -0800, Joerg <invalid(a)invalid.invalid> >wrote: > >>Jim Thompson wrote: >>> On Tue, 15 Dec 2009 07:52:54 -0600, Jim Yanik <jyanik(a)abuse.gov> >>> wrote: >>> >[snip] >>>> Manuals usually get better mileage,but that is changing in -some- >>>> models,because of the addition of lockup torque converters and CVTs. >>>> >>>> automatics eliminate the need for driver competence. >>>> >>>> Note that "unintended accelleration" crashes occur only with automatics. > >Nonsense, it's a stuck accelerator pedal. So shoving in clutch or >pushing PRNDL handle into neutral... what's the difference? The clutch linkage doesn't go through the computer. >>They should start teaching the basics again in drivers ed. Like how a >>car works. In Germany you used to not be able to get a license unless >>you could explain how an engine worked, and how other stuff such as >>clutch, gear box or differential worked. >> >>We still learned how to hobble a stalled car off railroad tracks by >>using starter, clutch and first gear. > >If you think fast. In 1957 lost 5 high school classmates who skidded >on the ice and got stuck on the track. Got hit by a Norfolk and >Western coal train doing about 100MPH :-( > >(Thompson's rule: RUN perpendicular to the tracks ;-) > >>Of course now they have switches >>on the clutch that don't let the starter engage unless fully depressed >>which defeats that extra safety measure. > >That's really not new. I had a 1950 Nash and a 1953 Hudson Jet that >both required full depression of the clutch to activate the starter >switch. But your starter switch was *on* the floor boards. ;-) >> >> >>> You're living in the past... I can't recall any car using a purely >>> "slush" type torque converter for at least 30 years, maybe longer. >>> >> >>But they all have to keep sloshing around some of the oil around the >>shaft lock. There's a reason why even new automatic transmissions run >>hotter than gear boxes. And warmer = more losses. > >Keep deluding yourself... you're fitting better and better into >Californication ;-) Cruel.
From: krw on 15 Dec 2009 18:49 On Tue, 15 Dec 2009 09:09:04 -0800, Joerg <invalid(a)invalid.invalid> wrote: >Jim Thompson wrote: >> On Tue, 15 Dec 2009 08:02:56 -0800, Joerg <invalid(a)invalid.invalid> >> wrote: >> >>> Jim Thompson wrote: >>>> On Tue, 15 Dec 2009 07:52:54 -0600, Jim Yanik <jyanik(a)abuse.gov> >>>> wrote: >>>> >> [snip] >>>>> Manuals usually get better mileage,but that is changing in -some- >>>>> models,because of the addition of lockup torque converters and CVTs. >>>>> >>>>> automatics eliminate the need for driver competence. >>>>> >>>>> Note that "unintended accelleration" crashes occur only with automatics. >> >> Nonsense, it's a stuck accelerator pedal. So shoving in clutch or >> pushing PRNDL handle into neutral... what's the difference? >> > >How about the brake? Aircraft brakes must be able to hold the whole >thing in one location with full thrust applied on all engines. Isn't >there a similar rule for cars? There should be. Holding one (either case) is different than stopping one. >>> They should start teaching the basics again in drivers ed. Like how a >>> car works. In Germany you used to not be able to get a license unless >>> you could explain how an engine worked, and how other stuff such as >>> clutch, gear box or differential worked. >>> >>> We still learned how to hobble a stalled car off railroad tracks by >>> using starter, clutch and first gear. >> >> If you think fast. In 1957 lost 5 high school classmates who skidded >> on the ice and got stuck on the track. Got hit by a Norfolk and >> Western coal train doing about 100MPH :-( >> >> (Thompson's rule: RUN perpendicular to the tracks ;-) >> >>> Of course now they have switches >>> on the clutch that don't let the starter engage unless fully depressed >>> which defeats that extra safety measure. >> >> That's really not new. I had a 1950 Nash and a 1953 Hudson Jet that >> both required full depression of the clutch to activate the starter >> switch. >> > >Luckily one can remove that "feature". > > >>> >>>> You're living in the past... I can't recall any car using a purely >>>> "slush" type torque converter for at least 30 years, maybe longer. >>>> >>> But they all have to keep sloshing around some of the oil around the >>> shaft lock. There's a reason why even new automatic transmissions run >>> hotter than gear boxes. And warmer = more losses. >> >> Keep deluding yourself... you're fitting better and better into >> Californication ;-) >> > >Well, do you know any car where the automatic version eats less fuel >than the manual? Not just on paper but in real tests.
From: krw on 15 Dec 2009 18:53
On Tue, 15 Dec 2009 11:30:41 -0800, "Joel Koltner" <zapwireDASHgroups(a)yahoo.com> wrote: >Here's what the Car Talk guys have to say: > >Tom: So there's no longer any good economic argument for driving a standard >transmission...especially when you factor in the inevitable clutch job or two >you'll need. It's purely a matter of preference these days. If you like >shifting, then get a stick shift. How about the initial $1000 (or more)? >Ray: But if you have better things to do with your right hand and left foot >while you drive, get an automatic, and don't worry about the mileage >difference. Or you have issues with your feet and knees. >(There's more discussion about how these things work -- they're targeting a >rather non-technical audience, of course -- here: >http://www.cartalk.com/content/columns/Archive/1993/September/09.html . I >realize that Joerg managed to drive his Citreon a quarter-million miles >without ever needing a new clutch, but the average soccer mom isn't quite so >gentle to them. :-) ) > >---Joel > > |