Discussion in 'Off-Topic' started by beenthere, Jun 1, 2011.

  1. beenthere

    Thread Starter Retired Moderator

    Apr 20, 2004
    Now and again, one gets to bite the biter.

    In this case, a character in Europe has been making a research instrument and touting it as the absolutely best that can possibly be made. It happens that I am the only competition on the planet, and make a significantly different instrument (which the USDA has finally approved the patent on).

    The fun now is that I have on my workbench a recent European instrument to reverse engineer. I can't help but notice that a contact that is made external to the instrument is soldered with lead-free solder (RoHS, ya know). But inside, all them solder joints are tin-lead. He uses phenolic boards, so the pure tin would lift the traces.

    To complete the silliness, the head amplifier that is placed close to the biological signals being collected, uses a CA3420 op amp, perhaps circa 1983. It is housed in a DB-25 shell - plastic with aluminum flash. The BNC jack fits the cable path. Contact is by tightening the nut to a light friction fit.

    Inside, though, is the same crap used since 1985. Like a 741 op amp. And this clown claims to have the best stuff possible. The control for the applied substrate voltage is not even marked in a meaningful way. The schematic is strange. This is a hobbyist level instrument at best.

    I see significant noise in the power supply - and in the output, as a 741 faithfully passes rail noise right out the output. He uses a overall gain of 100 and 8 bits conversion to do electrophysiology recordings. There is lots of noise in the baseline and drift is significant.

    He has proposed an "ideal" AC instrument. Having made one, he dismisses it as totally insignificant as his did not produce a usable output. He seems to think the principle is similar to AM radio.

    That's odd, as I have been producing such instruments for many years. With gains of 10,000 and a flat baseline using 14 bit conversions. Quite a number of papers are in print now that utterly disprove his contentions about his instrument. Now I get the satisfaction of demonstrating just how poorly made it is.

    I feel better now.
  2. TBayBoy


    May 25, 2011
    Where's the like button :)
  3. magnet18

    Senior Member

    Dec 22, 2010
    What are these things?
  4. loosewire

    AAC Fanatic!

    Apr 25, 2008
    @ Benethere,I have my U.S.D.A.............They have my....S.S.......
    I have there .................coverage. I have completed 2 projects.
    Anymore would give my privacy away.You have the records,I suspect
    they are private. Thanks Loosewire,the real thing.2012 may be a good thing
    at the patent office,if there pants were not so tight,and there 90 day rules.
    That place is tough,rough and hard to move,I did get to talk to a human
    There are people behind the scene that know there stuff,they try to be fair.
    My contact with them had nothing to do with U.S.D.A.for the record.
    I wonder if the general public know that all universities work thru U.S.D.A.
    for patents on very minute things thru out the world.
    Last edited: Jun 2, 2011
  5. atferrari

    AAC Fanatic!

    Jan 6, 2004
    Wish you said that you feel better because yours is better made.
  6. Wendy


    Mar 24, 2008
    Maybe you read something different, but what I read Beenthere said exactly that. Better specs, better parts, better design.
  7. atferrari

    AAC Fanatic!

    Jan 6, 2004


    Now I get the satisfaction of demonstrating just how poorly made it is.
  8. magnet18

    Senior Member

    Dec 22, 2010
    He was talking about the other guys thing, not his.
  9. Georacer


    Nov 25, 2009
    Meh, sometimes a little less humility doesn't hurt...
  10. Wendy


    Mar 24, 2008
    Depends, if someone tweaks your nose you are allowed to tweak back. Humility goes towards judging others too you know.
  11. #12


    Nov 30, 2010
    Reminds me of when I was a student. The boss hired a "real" engineer. Two weeks later, the transformer man came to me and said "it can't be done, but they won't listen to me".

    I went to the school computer, wrote about 15 lines of program, and proved you can't put that many turns of that wire in that torroid.

    I simply laid the printout of the program and the results on the bosses desk and walked out so he couldn't see me smiling.