On Saturday, March 24, 2012 11:22:52 PM Erik Christiansen did opine: > On 24.03.12 11:23, gene heskett wrote: > > But would you believe the shack no longer carries the insulator kits > > for hot tabbed TO-220's? So I came home & spent the rest of the > > afternoon demolishing an Antec 600w psu that did the usual Antec > > failure, its 5 volts was down to 4.82, exactly 2 weeks out of > > warranty 2 years ago. 2nd time a high priced Antec has done that to > > me. To get 2 only to-220 insulation kits out of it, and of course a > > huge supply on multicolored wires to finish up my box with. > > Some of the PSUs I've stripped had one big strip of it for a whole row > of TO-220s. If pushed, I'd mount the LM317 on an Al heat spreader plate > to give 10 times the area of the TO-220 tab, then sandwich a strip of > the insulator between that and the real heatsink, held with some nylon > bolts. That should give a tenth of the temperature drop for the same > heat flow. Maybe Digikey has rolls of the stuff?
Might have, didn't check. I was worried about a parport cable I won't see the stuff to make till I'm due at Block with my taxes. That is a 5 letter word, very similar to the 4 letter group in connotation. > Either that, or mount the LM317 directly on the heatsink, mounted on > nylon standoffs, inside the case, somewhere in that wind tunnel you're > making with the supercharged fan farm? ;-) Even at a 20F heat rise, it has another 140F or more to go before its in trouble. I don't believe I'll worry about it. (till it fails, but I say that in a whisper so Murphy can't hear me) It is directly on the case wall, and the case wall is .250" alu, so once the heat is past the insulator, it has a pound or so of alu to warm up. > > So that goes in the box next. I have some lexan, and am considering > > machining the lid to add a window above the C1G so I can see all them > > purty leds flickering away as it works. > > That seems worth doing, especially if it goes up on that high shelf, > where it's highly visible. Also handy to troubleshoot by removing the window. I got that about 75% done tonight, then discovered I had to expand the window to the rear by an additional 1/2" to gain access to the back row of output connections. But I have more lexan, so as long as I can machine the stuff (that's fun in case you've not tried it, as a std mill bastard file just bounces off it). But I can remount it on the mill and expand that in perhaps an hours worth of driving it by the arrow keys so its not a show stopper. The standoffs to hold the card at the correct elevation might be though. If I just cut tubing, I'll need full inch long 4-40 bolts. And I haven't seen any of those critters recently. Fasten-all quits at 3/4", I was there last week. :( > > On Saturday, March 24, 2012 10:07:19 AM Erik Christiansen did opine: > > > Having just finished subroutines in the translator, I'm about to > > > embark on while loops, and was just looking in the on-line doco for > > > a declaration on whether they have their own scope. Your experience > > > suggests that is the case. Then they should perhaps be demarcated > > > in the same way as subroutines. > > After reading these docs: > http://www.linuxcnc.org/docs/devel/html/gcode/overview.html#_parameters_ > variables_a_id_sec _parameters_a > > it seems clear that the only local scope in LinuxCNC gcode is in > subroutines: > > آ» > Scope > The scope of a parameter is either global, or local within a > subroutine. آ« > > That only deepens the mystery of your variable disappearing on leaving a > while loop. > The only conclusion I was able to reach was that the while loop was using the same looping mechanism as a sub/endsub used. > Erik Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> May Euell Gibbons eat your only copy of the manual! ------------------------------------------------------------------------------ This SF email is sponsosred by: Try Windows Azure free for 90 days Click Here http://p.sf.net/sfu/sfd2d-msazure _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
