Resistor Circuits Calculator

Discussion in 'Electronics Resources' started by joeyd999, Jul 14, 2011.

  1. joeyd999

    Thread Starter AAC Fanatic!

    Jun 6, 2011
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    Hi, Guys.

    Back around 1994 I wrote a couple of applications to assist in designing optimal resistor divider circuits. They were written in Borland Turbo Pascal for Windows for Windows 3.1, but they still seem to work well on XP. I haven't tried them on Vista or Win 7, though.

    The idea for the software came from an engineering problem I had. I was diagnosing a production yield issue on a particular product where a certain percentage of units were uncalibratable. I did some calculations and realized that a voltage divider, with the resistor values chosen, would not always provide a proper output voltage when turning the pot through its range. I recomputed the resistor values, taking the resistor and pot tolerances into account, and the problem was solved.

    I also learned early in my career that multiturn pots are *lousy*. They provide excellent setability, but rotten stability. Mechanical shocks and wiper hysteresis would make units go out of calibration in the field. I decided that all circuits using pots should use single turn pots only. But this meant that any dividers using pots should be designed optimally to achieve the best setablity possible given various sources of error.

    The computations are complex, and I originally did them on a spreadsheet. Finally, I wrote "Resistor Circuits Calculator" ("ResCalc" for short), to automate this process.

    I don't design with pots anymore (or rarely, EEPOTS), but for those of you who do, I am attaching my software here in the hopes that it might help someone.

    There is a short README file that gives some basic instructions on how to use this relatively simple set of programs.

    There are six different circuits the programs calculate:

    Ratiometric Divider
    Voltage Divider
    Non-Inverting Amp
    Inverting Amp
    Voltage Reference
    Voltage Regulator

    Enjoy.
     
  2. SgtWookie

    Expert

    Jul 17, 2007
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    My system is running 64-bit Windows 7, and the programs are not compatible with it.

    Do you happen to have the Excel spreadsheet you used before you wrote the programs?
     
  3. joeyd999

    Thread Starter AAC Fanatic!

    Jun 6, 2011
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    Sorry...the original spreadsheets were made in an old version of Microsoft Works for Windows. Even I cannot read them (or convert them) any longer.

    The ResCalc tools will run fine under Wine if you happen to have a Linux box.
     
  4. SgtWookie

    Expert

    Jul 17, 2007
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    Gee, even if they are quite old, you should be able to download converters for it for MS Excel.

    Unfortunately, I don't have a Linux box. I have another system running XP, but it's been disconnected for a couple of months now.
     
  5. joeyd999

    Thread Starter AAC Fanatic!

    Jun 6, 2011
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    You'd think. Unfortunately, there is no such beast.

    You are in luck! Download a copy of Ubuntu and install it on the old XP box...it'll give it new life!
     
  6. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Did you ever try open office to convert them?
    http://www.openoffice.org/

    I have been able to read older files, even when microsoft did not have any converter for them enymore.

    Bertus
     
  7. joeyd999

    Thread Starter AAC Fanatic!

    Jun 6, 2011
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    No, Ooo or LibreOffice cannot open them either....we are talking obsolete software from the early 90's here.
     
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