On Monday, February 06, 2012 03:05:26 AM Kirk Wallace did opine: > On Mon, 2012-02-06 at 05:08 +0000, N. Christopher Perry wrote: > > Thanks Kirk, > > > > I did as you suggested, and while I was at it I measured the series > > current when shortedï»؟ and found that it was ~2mA. My pulldowns were > > in fact too high an impedance. I dropped them to ~300 ohms and > > everything is now working as expected. > > > > N.C. > > I'm glad you got it sorted out, but I think it was Gene that caught the > resistor value being too high. I'll put a gold star by his name, and > requisition another beer or two for a toast.
I'll have to take a rain check on the beer, Kirk, my sugar responded to eating normal food today & its still 200+. Damned meter won't let me get away with anything anymore. :( But in an earlier post Christopher said he saw 2 ma on his meter. 2 mills through a 300 ohm resistor is courting noise trouble, big time because that leaves his logic zero voltage at .6 volts or more. 100 ohms or so would make it many times more reliable as 0.6 volts is only maybe 50 millivolts from turning into a raging bully of a problem child, no noise margin at all. With CMOS construction it could be a little better but not a lot. And neither of the 3 of us have a clue what process that parport driver might be. I think he said it was a D510, and I'll bet that rain checked beer it is cmos since a TTL circuit would have a measurable effect on that boards power budget, but diddled enough to work with TTL signal levels. Please measure it Christopher and tell me if I'm at least in the same ball park with my .6 volt SWAG. This is the voltage on the parport end of the wire I am talking about. Above that 300 ohm'er IOW. 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> First, I'm going to give you all the ANSWERS to today's test ... So just plug in your SONY WALKMANS and relax!! ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
