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EnigmaOne

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Posts posted by EnigmaOne

  1. Yes, it would be just fine.

    In my home/garage shop, I'm powering several Fluke field DMMs (as well as a few DMMs that heretofore have no brand name--can't get any cheaper than that!) from a bunch of homebrew isolated/regulated power supplies that ended-up being built from surplus AC adapters that keep accumulating in my junk drawer.

    If you add a connector to make hook-up easier, be sure to preserve any water proof/resistant (silicone sealer and various acrylic/vinyl glues are your friends here) qualities that the DMM case might possess, because condensation inside a meter really sucks--particularly where the higher voltage measurements are concerned.

  2. After having a bit of a snooze, I find myself considering the current-sourcing capability and ripple output of the DC power supply that you might be using here.

    If you enable the LT' (lamp test) input of all of the 4511s that you're using (I'm assuming 5: - 2 each for the team scores and 1 for the quarter indicator), you're talking about 35 relays (can you use hockey pucks instead of the relays?) kicked-in and holding, in addition to the current requirements of the remainder of the circuitry (4511s, PLCs, etc); which, depending on the power supply involved, might be enough to bring out some ripple/instability on the positive supply rail. (The buzzing/chattering relays are usually an indicator of a voltage output that isn't flat.)

    If you've clamped the relays--and are buffer-driving them--and still have problems with toasted chips, I'd certainly look to the power supply output quality and the specific logic-input technique that you're using with the 4511s.

    Oh well...I'm off to get some more coffee.

  3. I'm also wondering what method you're using to drive the relays.

    In looking at the data sheet/app notes ( http://www.ortodoxism.ro/datasheets/fairchild/CD4511BC.pdf ), it would be my first inclination to drive the relays in the same manner as shown on page 6 for a common anode LED display, adding clamping diodes of something on the order of 1N4001 - 1N4004.

    Driving the relay with a general purpose NPN transistor, like the 2N3904, ( http://www.ortodoxism.ro/datasheets/fairchild/2N3904.pdf ) would definitely save your ICs from serious harm on the output-side in most cases.

    See the attached: 4511-relay.drive.png

    post-6324-14279142042544_thumb.png

  4. This may be a handy reference for you:
    http://www.pnc.edu/te/ecet157/LabReps.PDF
    which deals with 7476s.

    In short, you'd do a mod-10 counter implementation with 7476s, overflowing to a mod-6 counter implementation.

    Reset is the same as would be accomplished with a decade counter, but the NAND-ing (use 7400s) would be wired for a reset at a binary count of 0110.

    Considering the state of each Q and Q' at various count conditions, view the counter cascade as a whole, with an eye toward the reset condition for each counter stage. The solution should then be fairly obvious to you. (As in a program loop, the trick lies in specifying the terminal condition.)

    If you have problems figuring it out--which you should really try to do on your own first--post back and I'll give you a bit more information on the matter.

    [sp&g mods]

  5. ::: snicker :::
    The answer could be, "Yes--provided certain conditions are met." ;)

    I did download the zip and will see if I can get it running under WINE--hoping that there isn't a requirement for VB runtime modules.

    To geohad82: What external library calls--if any--are you making from the Logicworks 4 executable?

  6. If I may ask...which distro are you running?

    My question is occasioned by what sounds like problems with RPM or source dependencies in your case. They can, needless to say, be frustrating. (By the sound of the unmet dependencies you've mentioned, I'd even go so far as to hazard the guess that you're running some flavor of SuSE or Fedora Core.)

    You may find that the manner of dependency resolution with a Debian-based distribution like SimplyMEPIS or Kanotix will allow you to successfully install the gEDA Deb without the kinds of problems you're presently encountering.

    Uninstall is generally a matter of deleting the applicable directory in /usr/lib/, or /usr/share/ or /opt/; the associated binary in /usr/bin/ and the respective links to the application. Once you've done it a few times, you develop a feel of where to look, getting it right the first time.
    In the end analysis, this is much quicker and easier than dealing with a flakey "unwise.exe", the inevitable registry dross and a "strange acting" OS platform in the wake of the application removal.

    If you type "make clean" in the directory you're working with source code in, the object files and other temporary files are deleted, and you can start a compilation run again. (For future reference.)

    ::: a bit of time passes :::

    I have to laugh at myself a bit here, because it looks like I've been too busy lately.
    I was considering installing gEDA, because it looks like something I could get a kick out of using but, as it so happens, I already have it installed and I simply wasn't aware of it. From what I can tell, it was amongst a block of around 400 programs I installed a few weeks back. I guess I'll have to give it a whirl one of these days.

    How about a suggestion? :D
    Since you've already re-installed your distro once, you really don't lose anything by trying the following...

    Open up a console session* and:

    [email protected][example.user]$ su
    Password:
    [email protected][root]# mkdir /distros
    [email protected][root]# cd /distros
    [email protected][distros]# kwrite ./getsm2004.06.sh
    

    enter the following lines:

    #!/bin/bash
    wget -c ftp://ftp.ibiblio.org/pub/linux/distributions/mepis/released/SimplyMEPIS-2004.06.iso.md5sum
    wget -c ftp://ftp.ibiblio.org/pub/linux/distributions/mepis/released/SimplyMEPIS-2004.06.iso
    

    and close the file, then:

    [email protected][distros]# chmod 755 getsm2004.06.sh
    [email protected][distros]# nohup ./getsm2004.06.sh
    

    You'll get "Appending output to nohup.out" as your response. You can close the console session and surf, do your work, listen to CDs and OGGs, do whatever you want, letting the download continue until it's finished...even logout if you desire...just leave the machine up and running. As popular as this release currently is, the download will stall and lose the connection to the server. Not to worry, since wget will pick back up where it left off when the connection is re-established. When that's done, you can check the md5 against the .iso and make sure you have an uncorrupted file; then burn it to a blank CD-R; the easiest way of doing that being at the command line:

    [email protected][example.user]$ su
    Password:
    [email protected][root]# cd /distros
    [email protected][distros]# /usr/bin/cdrecord --scanbus
    Cdrecord-Clone 2.01a34 (i686-pc-linux-gnu) Copyright © 1995-2004 Jörg Schilling
    
    Linux sg driver version: 3.5.31
    Using libscg version 'schily-0.8'.
    scsibus0:
            X,Y,Z     ?) Something that indicates that it's your CD-Burner
    

    write down whatever "X,Y,Z" happens to be and use it in the next command (replacing "speed=16" with the burning speed appropriate to your drive):

    [email protected][root]# /usr/bin/cdrecord dev="X,Y,Z" fs=8192k driveropts=burnfree -v -useinfo speed=16 -dao -eject -pad -overburn -data "/distros/SimplyMEPIS-2004.06.iso"
    

    Watching this screen is boring, so watch Rin & Stimpy, or some old Hawaii-50 reruns. When the CD's out of the oven, boot with it and login as root. (You get 3 guesses what the root password is for the Live-CD portion, and it's not "password".) You should have an "Mepis Installation Center" icon on the root desktop. livecddesktop.png Click on it and go through about a 10 minute installation process which will be done on the first and only re-boot. Login as a normal user (if you created one, and you should have). Run another console session. su again.

    [email protected][root]# apt-get update; apt-get upgrade; apt-get install synaptic
    


    You'll get scrolling text and maybe a couple of questions (go with the defaults) and you'll be done. Suffice it to say that you've:
    1.) updated your local repository listings,
    2.) upgraded your OS and applications and
    3.) installed the Synaptic package manager, if you prefer to use that instead of Kpackage;
    in a single shot.
    Close the session because for the next one we'll use the GUI to do the quick install.

    Run: K -> System -> Kpackage
    Settings -> Configure Kpackage... -> Types -> APT: Debian
    Enable and click "Location of Packages" -> A1
    Make sure the package locations and enablement agrees with those shown in the attached screen shot.
    Close that up and...

    Click on the blue, "Reload" button on the left.
    Browse the repository tree to:
    DEBAPT -> electronics (10th sub-directory) -> geda (13th package in the directory)
    [ Or just do a "Find File" on the text: geda ]
    Mark geda, and the 7 packages below it, for installation (see the attached screen shot).
    Wander around and see if there are any other programs you'd like to install as well.
    Click "Install Marked" and sit back while everything happens.
    At most you'll be told that one or two additional packages are going to be installed to satisfy dependencies for geda or a geda component.

    When that's done:
    K -> System -> Settings -> MenuEditor
    Create a new menu item (I put mine under Applications -> Browse All -> Apps -> Technical) with a command invocation of: /usr/bin/geda
    Choose an icon for it, and save the configuration.
    Run gEDA in the usual GUI manner.

    Remember that there is some poor sap out there who is on his 3 or 4th reboot, on a legacy OS install that he started before you started installing Mepis. He still has yet to run windoze update and install apps; while you have a fully-usable, updated and secure installation right now.

    Anyway, if you don't want to bail-out on the distro you have now, I still think you'll find something to your liking in what is already out there; and the above can be relegated to the realm of the academic, or simply ascribed to my propensity for writing really long posts :o .


    *For all those GNU/Linux detractors out there, I'm giving autir command line instructions that will work on any distribution or release of GNU/Linux. I don't have to know anything about his system, distribution, GUI or installed programs for this to work correctly.

    post-6324-14279142038615_thumb.png

  7. I believe that the 74150 multiplexer is what you're looking for.
    See:
    http://www.qsl.net/yo5ofh/data_sheets/74150.htm
    and
    http://webpages.ull.es/users/fexposit/74150.pdf

    Ok....forget that....I see that you're looking for an analog multiplexer now (darned old eyes!), so you'd actually be interested in something along the lines of:
    http://www.intersil.com/products/deviceinfo.asp?pn=HI-518

    or you could do an implementation of your own, using a series of JFETs or MOSFETs, digitally selected by something like a 74154 (1 of 16 selector), for 4-bit addressability.
    Source: http://www.web-tronics.com/74154.html
    Basic Data Sheet (non-pararmetric data): http://upgrade.cntc.ac.kr/data/ttl/74154.html
    Mfr Data Sheet: http://www.sharpmz.org/download/74154.pdf

  8. To the issue of making the magnetron in question smaller:
    You're dealing with physically and electrically resonant structures. If you change the proportionate size of the magnetron cavaties, you'll be--in my understanding of the matter--increasing the microwave frequency of the overall design. It's likely that dertain driving components will have to be changed commensurately.

    It looks like a full re-work, from where I'm sitting.

  9. I've built some pretty bad looking projects in my day, but nothing on this kind of scale.

    I'm opting for a low-precision digital thermometer myself--given the mix of what looks like RCA cans in there. A vintage circuit to be sure.

    I can go for leaning in the direction of art. It would look kind of cool, and a bit more stable, encapsulated in good-quality resin.

    Only after seeing this, have I come up with some similar ideas that would make my wife roll her eyes. I could probably be talked into something like that. ;)

  10. Hmmmm....I'm thinking that a simple, 24VDC, solenoid-operated, irrigation (sprinkler) valve body and head would be the exact thing you're looking for.

    [added]
    After some thought, you might also get away with using a solenoid-controlled valve for a refrigerator/freezer icemaker sub-assembly...probably quite a bit cheaper, although it will be operated by mains voltage.
    In that case, you could swap-out the coil for a low-voltage coil, or use a SSR to switch the mains voltage to the solenoid coil.

  11. Heh...most fab shops seem to go out of their way to get it wrong on the first go-around. It's not worth the time and hassle of waiting for it to be done right the second or third time they take a crack at it.

    My favorite method is to reverse the image and to laser print to transparency stock at 1:1. Use this positive mask to expose a photoresist coated board.

    Develop the photoresist and etch in the usual manner (agitated Ferric Chloride).

    I get perfect boards fast enough for my prototyping needs.

  12. Hmmmm....Looks like a "war" to me, but I won't get involved in it other than to say that anyone who eschews Linux simply hasn't tried it, or hasn't given it a fair hearing.
    Usability objections were actually overcome a while back, so the "slice-level" generally separates die-hard m$-only gamers from the rest of us. Asi es la vida.

    You can run the "old school" version of Orcad under DOS emulation in Linux. It's possible that later versions of Orcad will run under WINE, but I quit keeping up with the proggie when they went windoze-only, so I can't give a definitive "yes" or "no" to any question of "will it work?"

    You could try dual-booting distros, and go with something like SimplyMEPIS-2004.06 and pick up the Debs through Kpackage or Synaptic. Might be the easiest way of doing the install, instead of compiling the sources. (gEDA actually looks like something I'll try myself.)

    XCcircuit, Dia, Electric, KSimus, PCB and QCad are all possibilities for design/sim software for your stated needs; each one having its respective strengths and weaknesses, of course, so YMMV.
    The above are FOSS programs and, thus, are primarily directed away from the legacy software market; although you may find that some have been back-ported to various flavors of windoze.

    I can't offer anything productive to your secondary-search for zero-monetary-cost schematic design & simulatiors for xp, since I've never used m$ software in my business or for personal use.

    A SourceForge search might still yield something for you in that venue though, and you might even find something that you like that is in the process of back-porting to legacy platforms (or soon will be).

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