Cold spray, where do you buy?
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From: MooseFET on 11 Apr 2010 11:46 On Apr 8, 2:19 pm, Joerg <inva...(a)invalid.invalid> wrote: > Gents, > > Running low on cold spray. Digikey doesn't sell it anymore, maybe > because of shipment safety rules and regs. RadioShack is also dry. > > Where can one get that stuff locally? Slightly off topic but interesting if you are doing a lot of local cooling: http://www.exair.com/en-US/Primary%20Navigation/Products/Vortex%20Tubes%20and%20Spot%20Cooling/Pages/Vortex%20Tubes%20and%20Spot%20Cooling%20Home.aspx
From: Spehro Pefhany on 11 Apr 2010 12:02 On Sun, 11 Apr 2010 11:28:52 -0400, Spehro Pefhany <speffSNIP(a)interlogDOTyou.knowwhat> wrote: > It does leave a quite >noticable residue, so it might affect analog circuits. "It" referring to the 3M product with bitterant, of course, and noticable by humans perhaps not by circuits. Here is info on the substance they are likely using: http://en.wikipedia.org/wiki/Denatonium http://www.bitrex.com/ http://www.sciencelab.com/msds.php?msdsId=9923674 Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff(a)interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
From: John Larkin on 11 Apr 2010 12:03 On Sun, 11 Apr 2010 11:42:24 +0200, whygee <yg(a)yg.yg> wrote: >Joerg wrote: >> I always wondered why FPGA don't have a feature to program an on-chip >> temperature sensor onto one pin, or at least a diode path. uC often have >> that, for example the MSP430 series. >The Actel Fusion family can do pretty temperature measurements, >but they are ... a bit expensive. >Maybe a ring oscillator in the FPGA fabric, >with the output frequency compared to a stable >external oscillator, can help ? > Given that the clock is usually derived from an XO, you could make a ring oscillator, divide it down, and measure its frequency (it's easy to build a frequency counter!) against the clock, compute an error, make a delta-sigma DAC, and servo the external core power supply to correct. That should flatten out the gate prop delay tc pretty well, although different routing delays will still have different TCs. I guess routing delay TCs are the nasty problem. How come so many posters here have no name, or an obviously bogus one? John
From: John Larkin on 11 Apr 2010 12:05 On Sun, 11 Apr 2010 08:46:02 -0700 (PDT), MooseFET <kensmith(a)rahul.net> wrote: >On Apr 8, 2:19�pm, Joerg <inva...(a)invalid.invalid> wrote: >> Gents, >> >> Running low on cold spray. Digikey doesn't sell it anymore, maybe >> because of shipment safety rules and regs. RadioShack is also dry. >> >> Where can one get that stuff locally? > >Slightly off topic but interesting if you are doing a lot of local >cooling: >http://www.exair.com/en-US/Primary%20Navigation/Products/Vortex%20Tubes%20and%20Spot%20Cooling/Pages/Vortex%20Tubes%20and%20Spot%20Cooling%20Home.aspx > > We tried a vortex tube and were disappointed. Not much cooling and *very* noisy. John
From: Spehro Pefhany on 11 Apr 2010 12:21
On Sun, 11 Apr 2010 09:05:49 -0700, the renowned John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Sun, 11 Apr 2010 08:46:02 -0700 (PDT), MooseFET ><kensmith(a)rahul.net> wrote: > >>On Apr 8, 2:19�pm, Joerg <inva...(a)invalid.invalid> wrote: >>> Gents, >>> >>> Running low on cold spray. Digikey doesn't sell it anymore, maybe >>> because of shipment safety rules and regs. RadioShack is also dry. >>> >>> Where can one get that stuff locally? >> >>Slightly off topic but interesting if you are doing a lot of local >>cooling: >>http://www.exair.com/en-US/Primary%20Navigation/Products/Vortex%20Tubes%20and%20Spot%20Cooling/Pages/Vortex%20Tubes%20and%20Spot%20Cooling%20Home.aspx >> >> > >We tried a vortex tube and were disappointed. Not much cooling and >*very* noisy. > >John I've got a commercial one that I was just (in the last 30 seconds!) playing with. It has a sort of muffler on the hot air output port, but is still pretty noisy and uses a lot of air volume (but I was expecting that). I think I might have a real application for it (first time since finding Ranque-Hilsh (actually they only credited the latter) in an old Amateur Scientist column decades ago)- but it's oddball in that the air is there and comes almost for free. http://www.visi.com/~darus/hilsch/ Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff(a)interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |