Instrumentation Amplifiers

Discussion in 'The Projects Forum' started by tturner, Jun 15, 2012.

  1. tturner

    Thread Starter New Member

    Jun 15, 2012
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    Trying to make sense of these products. I am working with a Japanese company that produces Instrumentation Amps. (Differential, I/V Converter, Isolation, Voltage, High Voltage and Broadband)

    These are all either board based or in their own little cabinets. I think it has to do with power supplies. Some of these use batteries and a "charger" to supply operating voltage to the device.

    http://www.turtle-ind.co.jp/en/01products_info/t-01xgaz.html

    I know that many of these funtions are offered in a chip and commonly in SIP or DIP packages.

    My question is, "Who uses the type of Amps that Turtle makes? Why?"
    Thanks
    Tom Turner
    <SNIP>
     
    Last edited by a moderator: Jun 15, 2012
  2. Wendy

    Moderator

    Mar 24, 2008
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    Bertus beat me to this while I was mulling over your thread.

    To my eye this comes very close to spam, but I will let it pass.

    There are many applications for INAs. The big one is what they say they are, instrumentation for µC and other uses.
     
  3. tturner

    Thread Starter New Member

    Jun 15, 2012
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    No Spam on my part.

    I can make fire with flint, matches, piezo, battery or flamethrower. However, there is appropriate circumstances for each depending on fuel, cost, location, desired result, time, etc.

    My question about the Instrument Amps is trying to understand the appropriate circumstances for a self contained black box Amp vs an integrated chip solution.

    Obviously, if you need to make 400 copies of a custom setup, you would probably use the chip solution. I have hand soldered 50 proprietary measure and control PCBs with over 120 components on them we used to make variable caps. I get that idea from my manufacturing background.

    I am just trying to learn when someone needs to be able to connect some BNCs and tweak up the voltages and begin measuring.

    What are those circumstances?

    Thanks
    Tom Turner, VP
    ITA, Inc
     
  4. bertus

    Administrator

    Apr 5, 2008
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  5. #12

    Expert

    Nov 30, 2010
    16,252
    6,751
    When a person doesn't know how to design his own x10 or x100 amplifier, he buys a black box.
     
  6. tturner

    Thread Starter New Member

    Jun 15, 2012
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    Thanks for the reading. Will dive in.
    Tom
     
  7. tturner

    Thread Starter New Member

    Jun 15, 2012
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    Thanks #12 (possibly 32)

    GOOD now we are building the list of why black box amp might be chosen.

    1) When buy wins based on knowledge/skill. (Build vs Buy)

    Would you also say
    2) When getting the measurement is more important than spending time to make an amp, isolation circuit or to overcome some common ground buggaboo.
    (Your time is more valuable than a black box - Git R Done.)

    Any other times or reasons that a canned solution might make sense?
    I wonder about research measurement vs production measurement?
     
  8. wayneh

    Expert

    Sep 9, 2010
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    I spent a career making business decisions, many of which were make versus buy. The make-or-buy decision is a classic business example, thousands of decisions made every day, and you can find checklists and guides for making such decisions. You're not the first person to wrestle with the issue.

    There is a natural human bias towards make, at least in some humans, and in particular the humans that hang out here! :p Taking the opposite bias is usually the right way to go. It's fun to build things, but not usually a great decision unless the process and fun of doing the build is the primary goal. Choosing what to NOT focus your time on is a hard but critical decision.

    In general, you never want to make when you can buy. From a company point of view, even if your time is worth the savings, it may not be how the company wants you spending your precious time.

    If you need something you can't buy, the situation gets harder and other factors come into play: If you make a device, will it give an acceptable return on investment? Does it have any strategic, "company-specific knowledge" advantages? Does it give you some lasting competitive advantage? Can you change your requirements to avoid a DIY solution in the first place? If you think it's worth your time to build something, do you think you could convince someone else it's worth their time to build it for you? Would you pay an outside entity to build it for you?

    In other words, be brutal and suppress the urge. If in doubt, cut it out.
     
  9. tturner

    Thread Starter New Member

    Jun 15, 2012
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    Thanks wayneh:
    It seems that another reason for picking a canned or black box solution would be to reduce risk. If your phd hypothesis is going to ride on the measurement, you would rather use a standard device with documented inputs and outputs instead of something you cobbled together from a chip you bought from ChipsandSalsa.com.

    Who wants to cobble up some homegrown circuit to find out that the result is unbelievable?

    3) When buy wins because of risk avoidance. Packing your own parachute is smart, but MAKING your own parachute might not be so wise.

    Similar to this is the argument I used to make against white box DIY computers.

    Would you rather call tech support looking for help with a unique configuration that only a dozen people in the world share? Or would you rather have the configuration that Dell sold 10,000 units of this morning? My money is on the second choice. I want me and my tech support wizard to have thousands of other successful fixes in the bag before I ever get there.

    4) There is tech support safety in numbers. (The more folks with a problem, means more solutions in the database.)

    Do you see that as true.
    Thanks
    Tom
     
  10. tturner

    Thread Starter New Member

    Jun 15, 2012
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    Is there anyone out there with Scientific Research instrumentation experience? I am trying to understand what makes research instrumentation and process control or monitoring instrumentation different. Are the biases more toward build or buy for amps and isolation?
     
  11. mcasale

    Member

    Jul 18, 2011
    210
    12
    I've spent my career designing scientific measurement instruments. Usually, these products would sell 10- to 100-units a month, or more. Rarely would we buy a black box to do this. They are too expensive and usually don't have the performance we need (offsets, noise, dynamic range, etc.). Then there's the issue of how to fit it into your system. Does it just plug into an HPIB or USB port, or is it more real-time? I hope this helps.
     
  12. tturner

    Thread Starter New Member

    Jun 15, 2012
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    mcasale:
    Great input on output Amps

    Now I can add another 4 to my list.

    5) Make is preferred because performance or specs are too low. We need more capabililty than what is normally offered in a commercial product.

    6) Make is preferred because price is too high for a canned product. We can't find hi-perf amps that we can't make cheaper.

    7) Make when you need to tailor the speed and interface to the situation. Certain experiments may require realtime capture for controls and others are fine with data written to a file for later analysis.

    8) Physical and electrical integration challenges can force you to make when space or other factors make a black box impractical. If you need your amp or isolation very near to the source, a box with a wall wart power supply is not going to work. Especially if the source is inside an area that is really hostile.

    Does that catch the flavor mcasale??
    t
     
  13. mcasale

    Member

    Jul 18, 2011
    210
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    Yo, tturner, I couldn't have said it better myself!
     
  14. tturner

    Thread Starter New Member

    Jun 15, 2012
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    0
    Thanks Everyone!!

    So, I am starting to get the idea of when canned and custom built solutions are best. Now I am curious who the real players are in this space.

    Who makes canned black boxes for the Instrumentation Amp and Isolation user? What are the brand names? I only know of Vernier in the education market. Who else?

    Likewise,
    Who are the chip and packaged device makers? I think I know that TI and Analog Devices and Maxim are players. Who else am I missing?

    Thanks
    t
     
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