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What's on your test bench?

Discussion in 'Electronic Design' started by Phil O. Sopher, Nov 11, 2009.

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  1. Over a 40 year period of interest, I've gathered some
    test equipment, AF Genny, RF Genny, Freq Counter, High
    Impedance Voltmeter, Wheatstone Bridge, Oscilloscope.

    None of these is particularly small and all are at least a 6" cube.

    It seems to me that the same functionality could be achieved
    these days with perhaps just a few inches of bench space, but,
    would it be of any use?

    The eqpt I gathered together dates very much from the days of
    designing circuitry with individual componenents (R, L, C, BJT)
    and offers test and validation at that level, but nowadays we don't
    work at that level (even op amps have been around for that 40 year
    period).

    So, what do you have on your test bench these days, how big is it,
    did you design it yourself, and what would you recommend to the
    budding circuit designer of today who isn't in the industry and therefore
    does not have access to Spice or Matlab to validate their designs?
     
  2. JW

    JW Guest

    At home:
    Lecroy 9374M scope
    Keithley 2000 DMM
    HP 5385A opt 004 counter
    Agilent 6643 power supply
    HP 8656B
    General Radio resistor decade box

    Other than the decade box, all bought defective on Ebay and repaired by
    myself.

    At Job #1
    Agilent 54810A scope
    Valhalla 2701B DC calibrator
    HP 745C AC calibrator
    Fluke 45 DMM
    Philips PM 2534 DMM
    Some crappy old B&K power supply
    Fluke 9100 and various pods

    At job #2
    Lecroy 9354L scope
    Keithley 2010 DMM
    Kiksui 300W electronic load
    HP 437 Power meter
    HP 8350A generator with various plug-ins
    EIP 545 counter
    EDC MV106 voltage standard.
    Amrel +-30V 3A power supply (forget model #)
    HP 5005 signature analyzer
    Bob Parker's blue ESR meter

    Don't really design anything, I'm a test equipment repair technician.
     
  3. Fred Bartoli

    Fred Bartoli Guest

    MooseFET a écrit :
    What? It's not calibrated in Fahrenheits?
     
  4. There's also Scilab. http://www.scilab.org/ which might be easier for
    Windows-based users.
     
  5. krw

    krw Guest

    At home? Nothing, if you don't count a couple of Fluke-77s and a
    couple of HF DVMs (left visible, used as bait). I don't do
    electronics at home. I get enough in the 55 hours/week or so at work.
     
  6. JW

    JW Guest

    The Lecroy 9374M scope had a problem with the battery back up circuit on
    the CPU board. Lecroy 93XX (and possibly other Lecroy) scopes are weird in
    that if the rechargeable battery falls below or above a certain voltage it
    locks up the CPU. In fact, if you disconnect the battery when it's up and
    running, the scope will freeze up. (Agilent 545XX scopes also lock up when
    the battery dies) This particular one's voltage would surge up to almost
    5V on a power-up and stay there, possibly back-feeding or latch-up from
    the real time clock - I found that putting a 33uF tantalum on the Vbat
    voltage would prevent that momentary surge. The floppy drive was also bad,
    I figured out how to adapt a standard slim floppy drive used in laptops to
    replace the oddball Epson drive.

    The Keithley 2000 would fail random self tests - a power supply re-cap
    fixed it. I just fixed a Keithley 2001 MEM2 with the exact same issue, but
    that one's for sale now. I don't need that kind of accuracy, and it's
    missing some functions that the 2000 has.

    The HP 5385A counter had a shorted over-voltage protection zener in the 5V
    digital supply.

    The Agilent 6643 power supply had a busted LCD display. Rather than spend
    $85 for a new one from Agilent, I found that their 3488A switch unit
    shares the same display - they can be had for peanuts; nobody wants 'em it
    seems. After replacing the display the supply would error out in
    overvoltage mode when programmed to output a voltage greater than 2VDC, a
    bad op-amp in the sense inputs.

    The HP 8656B, can't recall that one...
    More often than not, much of the stuff is quite repairable as long as
    someone hasn't already made a mess of it in a botched repair attempt. The
    only piece I bought and was never able to repair is a Tek 2430A which had
    bad CCDs - the chips are pretty much unobtanium these days. I'd say the
    most likely failures are:

    1. Battery failures
    2. Electrolytic cap failures
    3. Shorted or open semiconductors in power supply circuits.
    4. Oxidation of contacts.
    5. Mechanical failures

    Working part time for one of the used test equipment companies has allowed
    be to gain quite a bit of experience and knowledge in certain "magic
    bullet" fixes. Those are fixes where a particular piece is notorious for
    certain failures and cures. I'm always on the lookout on Ebay for those.
     
  7. krw

    krw Guest

    Funny. I expected flak from you. ;-)
     
  8. krw

    krw Guest

    If necessary I just go into work over the weekend. If there is
    something that really needs to be done it's no big deal.
     
  9. krw

    krw Guest

    I have the FPGA tools from the various manufacturers[*] loaded on my
    laptop but I've never used them in anger. I'm 13 miles, half
    interstate.
    Isn't that the time to read a book by the fire?


    [*] Yikes, are the FPGA sales types hungry! I'm getting calls every
    day from the four vendors.
     
  10. Jamie

    Jamie Guest

    You meant, COM/ACTIVEX/DCOM/OLE, correct?
     
  11. Pieyed Piper

    Pieyed Piper Guest

  12. Jamie

    Jamie Guest

  13. Pieyed Piper

    Pieyed Piper Guest

  14. Pieyed Piper

    Pieyed Piper Guest

    Only if your name is Dippity Doo Dah.
     
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