---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 11/11/06: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:02 AM - Re: Transistorture (Robert L. Nuckolls, III) 2. 05:11 AM - Re: 'Scope offer from Saelig (Robert L. Nuckolls, III) 3. 11:10 AM - Re: Transistorture (Fiveonepw@aol.com) 4. 09:14 PM - Re: Transistorture (Don Vs) ________________________________ Message 1 _____________________________________ Time: 05:02:36 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Transistorture At 07:46 PM 11/10/2006 -0500, you wrote: >In a message dated 11/10/2006 8:47:51 AM Central Standard Time, >nuckollsr@cox.net writes: >The schematic helped. See attached .pdf > >Amazing- once again you have taught and assisted beyond all expectations- >circuit B puts LED supply to ground potential for the big turn off! This >is too cool- lots of uses for this, time ta git busy (gotta figure out >packaging)... 8-) > >THANK YOU SIR!!! You're most welcome. Consider "potting". Small circuits like this can be simply spider-webbed together, checked for function and then potted in epoxy using just about any form of the right shape and volume. Since the epoxy offers the structural integrity, the enclosure need only hold things in place until the epoxy sets up. bundle the wires and put a sleeve of heat shrink over them so that there is some bend relief offered by the shrink where the wires exit the epoxy. Avoid fast setting epoxies . . . all epoxies warm up and the large volume applications using fast epoxy may get so hot as to boil over. Get some long pot life stuff, 30 minutes or more and it will probably work just fine. Once your circuit is suitably ensconced in plastic, you can bond a mounting plate to the bottom with E-6000. Bob . . . --------------------------------------------------------- < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > --------------------------------------------------------- ________________________________ Message 2 _____________________________________ Time: 05:11:51 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 'Scope offer from Saelig At 07:58 AM 11/10/2006 -0800, you wrote: > >Thanks Bob, > >We're thinking of getting some of these where I work for field techs. >Might get one to try out... Lots cheaper than the Teks, or the Fluke >196c that I have :} > >/Joe Depending on your budget, the OWON may be an excellent option. Don't forget ebay either. I have some folks at RAC and their kids who take Saturday morning classes I've taught out at WSU. A 'scope is one of those dead-nuts- simple ways to help people visualize the dynamics of circuit operation. I've been able to pick up perfectly serviceable 'scopes off ebay and fit them with new probes for under $150 total. I've acquired the occasional really nice one for under $250. While a 'scope is generally way down on the list of tools for the hobbyist, I've found it useful to push for early acquisition. With access to the 'scope, some of these kids are acquiring a hands-on, real-time visualization of circuit dynamics They're getting an introduction to range and domain graphical analysis even before they take algebra or calculus. When their teachers throw those concepts up on the board in coming years, the kids with the 'scopes will have an immediate and solid understand of the concepts and the utility they offer. Bob . . . ________________________________ Message 3 _____________________________________ Time: 11:10:14 AM PST US From: Fiveonepw@aol.com Subject: Re: AeroElectric-List: Transistorture In a message dated 11/11/2006 7:05:12 AM Central Standard Time, nuckollsr@cox.net writes: Consider "potting". Got it, thanks again! Mark do not archive ________________________________ Message 4 _____________________________________ Time: 09:14:27 PM PST US From: "Don Vs" Subject: RE: AeroElectric-List: Transistorture Bob, I would like to use a transistor to convert a normally open switch to normally closed. I need to switch a circut ground off. This would be very simple with a relay, but, I would like to use a transistor if this can be done. Is this a reasonable approach? If yes can you draw me a diagrtam? Thanks. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Robert L. Nuckolls, III Sent: Friday, November 10, 2006 6:43 AM Subject: Re: AeroElectric-List: Transistorture At 08:32 AM 11/10/2006 -0500, you wrote: >In a message dated 11/10/2006 7:16:37 AM Central Standard Time, >nuckollsr@cox.net writes: >Who did you talk to there? Was it on phone or by e-mail. > > >>> >Request was made by phone to John (dangit, do not recall last name) and >attached .pdf sent via e-mail in reply. Will monitor list to see if >attachment gets through, if not, will e-mail direct. > >Thanks! >Mark do not archive The schematic helped. See attached .pdf All parts are available from Radio Shack. You can wire two ways. One version turns LED ON when servo signal high, the other turns it OFF. Bob . . . --------------------------------------------------------- < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > ---------------------------------------------------------