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+/- 5 vdc signal to 0-10 vdc signal

Discussion in 'Electronic Design' started by Craig, Mar 10, 2008.

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  1. Craig

    Craig Guest

    I need to convert a +/- 5 vdc analog signal to a 0-10 vdc analog
    signal. In effect, 0.0 vdc needs to be shifted to 5 vdc. Is there a
    simple IC that can be used to do this?
  2. John Fields

    John Fields Guest

    View in Courier:

    VIN>--[10K]--+--------|+\ LM318
    | | >--+-->
    [10K] +--|-/ |
    | | | [10K]
    +5V | -15 |
  3. Guest

    Good grief. An LM318. Why? Farnell still stocks them, but they always
    were noisy and cranky. I never used one after the LF356 came on the
    market around 1974 - the LF356 wasn't quite a fast, but it was quiet
    and well behaved.

    If you need real speed these days, the LM318 isn't remotely

  4. John Fields

    John Fields Guest

    I don't see where the OP asked for speed or, in fact, for anything
    other than how to do the level shift with a simple IC.

    That's what he got and, of course, he's free to do any substitutions
    he chooses to.
  5. Guest

    So why suggest an obsolete and cranky - but moderately fast - op amp
    to do the job?

    The 741 is the traditional part for this sort of work - I prefer the
    OP-07 because it has no vices and a low offest voltage, but without
    some detail about the application you can't go very far.
  6. John Fields

    John Fields Guest

    Why not?

    That description fits you perfectly and yet you claim to be
    available for work.
    You can go far enough to design the circuit he asked for. Well, I
    can. YMMV.

    If you want to find out what the application is, why don't you just
    ask the OP what he's up to and then suggest what you consider to be
    a suitable part instead of whining about trivialities and trying to
    make trouble?
  7. Guest

    Since my skills aren't obsolete, the description doesn't fit me at all
    well; I've been tackling system design and analysis problems all
    through my career. The optimal solutions keep on changing as the
    technology progresses, so I'm forever finding out about new techniques
    and new components, rather than sticking to the stuff that worked when
    I started in on electronics, when the NE555 and the LM318 were new and
    modrately exciting.

    Your sorts of skills are presumably in demand for museums of
    technology where you can tell school-children about stone age
    electronics, next to the guy who makes Folsom points by bashing one
    bit of rock with another.

    Many of the example circuits in the data sheet have 5pF in parallel
    with 10k feedback resistors - it looks as if you can get away without
    it at a noise gain of two, which corresponds to your circuit, but the
    circuit won't settle fast without it, and you'd need another 5pF (or
    whatever) in parallel with the 10k to +5V, so your mileage does fall a
    little short.
    You may think that it is a trivial error to specify an wildly
    unsuitable amplier in an answer a dumb newby question. It wouldn't
    look trivial to the poor sucker who took your advice as gospel and
    then had to spend a week learning how to stop a fast amplifier from
  8. John Fields

    John Fields Guest

    Finding out about, but not being able to apply, eh?
    If that were true, I'm sure I'd have a sentence or two about your
    stuff in there.
    Dumbass, there's more to knapping than just direct percussion.

    Here are some examples of what can be done if someone knows what
    they're doing:

    Blah blah blah blah fucking blah.

    Too bad you couldn't come up with anything except whining after the
    fact, huh?

    I mean, even something as simple as this:

    ..                       +15
    ..                        |
    .. VIN>--[10K]--+--------|+\
    ..              |        |  >--+-->
    ..           [10K]   +--|-/   |
    ..              |     |   |  [10K]
    ..             +5V    |  -15   |
    ..                    +--------+
    ..                             |
    ..                           [10K]
    ..                             |
    ..                            GND
  9. Fred Bloggs

    Fred Bloggs Guest

    If ultra-high input impedance is a consideration and you have dual
    supplies then something like this is along the same lines:
    View in a fixed-width font such as Courier.
  10. Guest

    Not recently, no. And the projects I've been involved in were varied
    enough that my experience was always a couple of years (sometimes
    more) out of date when I had to dig it out and apply it to a new
    project - a couple of years of doing nothing but reading the trade
    literature won't have done me any good, but I've coped with similar
    gaps (due to doing something different) all through my career.

    Gigabit Logic's GaAs logic is strictly for museums these days, but the
    latest flavours of ECLinPS are about as fast, and appreciably cheaper.

    Carefully directed percussion
    That wouldn't hack it an argument in primary school.
    Why should I. You'd already posted it. It's a classic subtractor/
    differential amplifier circuit, though you didn't indentify it as
    such. You can find it in any decent text (Fig. 4.18 in the Art of
    Electronics for example).

    The only thing wrong with your post was that you suggested using the
    LM318 as the amplifier, which was daft, particularly since it is fast
    enough that the couple of pF to ground at the inputs presents an
    impedance comparable to the 5k of the resistor networks within the
    bandwidth of the amplifier, which is why you really should have shown
    the two extra capacitors - messy though that is an an ASCII circuit
    diagram. Something with less bandwidth (like a 741 or an OP-07), which
    is perfectly adequate in most applications, doesn't need the

    You blew it - in a small way - and I scored a gotcha. That isn't
    whining - as you'd appreciate if you'd ever done any serious
    electronics, rather than persisting in playing the retard in the 555
    sandpit ever since Hans Camenzind designed it back in 1971.

  11. That's no one's fault but yours for not even reading up on the latest
    components and doing designs just to stay in practice. You had no
    reason to find a job, and were too lazy to remain useful.

    -- is home to cowards and terrorists

    Add this line to your news proxy nfilter.dat file
    * drop Path:*!not-for-mail to drop all traffic.
  12. Guest

    Do read what I wrote. I do read the trade literature to find out what
    is going on. I don't do paper designs just for the exercise - it's a
    waste of time without a real problem to constrain your choices - but
    when a new component takes my fancy I do rough out how it might solve
    an old problem.

    You are welcome to your delusions about my situation - somebody like
    you who is in constant pain does need some kind of distraction (no
    matter how bizarre), and Central Florida isn't exactly the
    entertainment capital of the world, now that Jeb Bush isn't around
    winning elections for his brother by purging Democrats from the
    electoral roll.

  13. Yes the pain is 'so bad' that I go two or three days at a time before
    I absolutely have to take gabapentin for the diabetic neuropathy and
    only when I can't get to sleep at night. The rest of the time I can
    manage the pain without medication. What's your excuse?

    Yawn. Keep lying to yourself, Bill. No one really expects anything
    else from you. It speaks volumes that you found Jeb Bush entertaining.
    I'll bet you just LOVE root canals and having a colonoscopy.

    -- is home to cowards and terrorists

    Add this line to your news proxy nfilter.dat file
    * drop Path:*!not-for-mail to drop all traffic.
  14. Guest

  15. Guest

    Keep lying about me Michael - it's just one more way for you to
    demonstrate how out of touch with reality you really are.
    Dutch dentists use local anesthetics - root canal work is just boring,
    but I can sleep in a dentist's chair, which helps to pass the time.

    Those of my relatives who have been subjected to colonoscopy didn't
    enjoy it much, but didn't find it traumatic. I'm due to swallow an
    endoscopic ultrasound transducer in a couple of months so that my
    cardiologist can examine my heart from my eosophagus - a
    transesophageal echocardiogram

    I'll be delighted to get a chance to look at the transducer and the
    images - I worked on echo cardiography from 1976 to 1979 and really
    enjoyed it - though swallowing the transducer isn't going to be too
    much fun.
  16. Guest

    I don't do gratuitous insults - my insults are calibrated responses to
    the insults I get. Your idea of what constitutes good English
    expression does seem to be based on the depressingly low standards of
    rural Texas.

    That and the fact that you can't do better.
    It is a pity that you ignore the implicit expectation of similar
    expertise in the responses.
    But mostly because your idea of "common knowledge" is pretty
    restricted, and lots of what you think you know ain't so.
    Which is where you blew it.

    The "trick" - such as it is - is common knowledge, as is illustrated
    by the fact that you got to post it before I saw the query.

    As if you've got any choice.
    My appreciation of the 555's many defects has lead me to propose more
    cumbersome, expensive and accurate solutions on any number of
    occasions, but accuracy isn't exactly your thing.
    I do. Your "perfect" 555-based solution involved using a diode to
    further impair the 55''s already dire temperature stability, not that
    you understand the concept of temperature stability. The fact that you
    remember that thread with "particular glee" does illustrate your
    ignorance and your capacity for self-delusion.
  17. John Fields

    John Fields Guest

    Not at all fuss about typos, more a commentary on the continuous
    abuse of spelling and grammar. Probably unconsciously, but more's
    the pity...

    In which way did the OP insult you which made you feel that calling
    him a "dumb newby" was warranted?
    LOL, and even at that I'm able to pick out your errors and logical
    inconsistencies! What does that say about _your_ "standards"?
    Sure I can, but why bother?

    A wink's as good as a nod to a dead horse, don'tcha know.
    I don't, but from your "contributions" I've just resigned myself
    come to expect less from you than from the rest of us.
    Even if that were true, it doesn't make you less of an asshole.
    Nope, the circuit's good regardless of the choice of opamp, and had
    the OP been more specific about his requirements a possibly more
    appropriate device (or circuit) would have been recommended.
    The "trick" was to get the resistance ratios and the reference
    right, which you didn't do. All you did was start an argument for
    the purpose of feeding your insatiable ego.
    Sure I do.
    Sure it is, when it's warranted, but when all that's needed is plus
    or minus a couple of percent it's stupid to spend good money on
    getting to 0.1% for the sake of vanity.
  18. Guest

    It isn't an insult, but a description. The circuit that he wanted can
    be found in any decent text-book.

    When I post questions over Linux, I have characterise myself as a dumb
    newby, because in that area I need dumbnewby level explanations.

    Dream on.

    More self-delusion.

    You don't understand them so you soothe your ego by persuading
    yoursefl that there isn't anything there to understand.

  19. Yawn. You think that you are worth a lot more than you really are.
    As far as lying? You are an expert, making ASS-umtions about people that
    you've never met. No one beleives 90% of what you say. You presume to
    know everything about my medical problems, and you know almost nothing.
    I would tell you to get a life, but you've already wasted one.

    Try it sometime in an emergency situation where there is no pain
    killer availble, then get back to me.

    Why not? You expect us to belive eveything you say.

    -- is home to cowards and terrorists

    Add this line to your news proxy nfilter.dat file
    * drop Path:*!not-for-mail to drop all traffic.
  20. John Fields

    John Fields Guest

    Then his not knowing that made him an ignorant newbie, not a dumb
    newbie. You pretend to be fluent in English yet you appear to be
    oblivious to the difference.

    Perhaps feigning ignorance is better than having to admit your
    insult was gratuitous?

    I suspect so.
    In your case I believe "dumb newbie" is appropriate.

    Also, in order to be grammatically correct, your sentence needs a
    'to' between 'have' and 'characterize'
    See above.
    Yeah, just keep telling yourself that.
    It's not that there's nothing there to understand, it's just that
    it's often banal.
    True; you couldn't be any more of an asshole... ;)
    And what do you think your opinion about what my opinion is worth is
    worth, LOL!
    It's not that I don't appreciate it, it's that I don't _care_,
    because for me it's a non-issue.

    If the OP comes back with questions or more spec's then whatever
    needs to be done will be, and since you seem to be the one with his
    panties in a bunch about it you can field REV.A. Be my guest.

    Yeah, and???

    You think I should only take on the hard stuff and leave the easy
    stuff for knuckle-draggers like you?
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