Various Calculations

This program provides a set of various useful electronic calculations. In this version they are: Resistor Power, Voltage Divider, Parallel Resistors,
PI-net, T-net, Convert Numbers, dB % X, dBm dBU dBV, Rise Time, Serial Resistors, C Impedance,  L Impedance, NonInverting OP-amp
and Inverting OP-amp.


June 27, 2024  - New version 2.3


Changes from 2.2 to 2.3:


Convert Numbers:
 Positioning of cursor when adding characters didn't work as intended in any textbox.
 Registry key for checkboxes had wrong header.

Parallell and Serial Resistors
 When swapping between Parallell and Serial Resistors with R1 AND R2 as unknown the selected percentage was cleared.


Changes from 2.1 to 2.2:



Resistor Power:
Formatted values didn't show values inside brackets after Standard Resistor Values was selected or deselected.

Convert Numbers:
 Run Time Error when overflow, now warning message.

Help Form:
 Incorrect info about double click in an empty box.


Properties Form:
 OK button caption changed to Close.


Resistor Power:
 Added option so now also Power could be one of the fixed values i.e. two fixed and two ubknown.

Convert Numbers:
 Added options to select position of entered character (first or last).

Changes from 2.04 to 2.1:



All number boxes changed so they now work as usual with right click e.g. Copy or Paste.
Properties form now opens with <Ctrl> + Right Click or <Ctrl> + <Enter>  and Decimals form opens with <Shift> + Right Click or <Shift> + <Enter>


Changes from 2.03 to 2.04:



All symbol picture backgrounds were changed from older windows standard grey color to transparent background. 


Changes from 2.02 to 2.03:



 Tabs where Unknown had to be selected before numbers could be entered did accept a decimal point or comma which was converted to a leading
   zero + a decimal point even of no unknown had been selected and it could only be cleared by Clear All or after an unknown had been selected. 
 Pretty much all tabs with Prefix options had sometimes problems when another prefix was selected while all boxes had valid numbers.
 Entering a single decimal point or comma in a box with all text selected did not do anything if the selected text contained a decimal point and if not it
   added a decimal point at the beginning of text instead of replacing the whole text.
 Wrong Value messages on most tabs did not disable the Standard Values option while visible which could lead to a Run Time Error
   or incorrect values being calculated if Std values option was selected.



  Did not accept decimals correctly, fixed in v2.01 but back in v2.02.


Resistor Power:

 Error message wasn't always cleared. 


C Impedance & L Impedance: 

  Did not accept numbers < 0 and with one decimal which could sometimes cause a Run Time Error.
 Setting decimals on Z or F with an existing numeric value of value less than 1 or larger than or equal to 1000 did not work.

Rise Time:

  No Error message for entry of  0 on any box.

  Run Time Error if decimals is changed on Meas'd/Expected or DUT Tr before System Tr was defined.


NonInv and Inv OP amp:
 Returning from standard values didn't reenable the choice of E-96 or E-24.




C & L Impedance:

  Changed to show Mohms for values higher or equal to 1000 Mohms instead of ohms.


 Limits error messages changed.


dBm, dBU, dBV:
 dB limits changed to 120 dB.
 Error messages for overflow changed.

  dB ref type added to saved properties file.
 Minus sign now allowed on dB entry box.


Changes from 2.01 to 2.02:



 Convert Numbers Binary changed so inputs are done from the left. LSB is the rightmost digit so before input had to done backwards.


Changes from 2.0 to 2.01:



  PI-net didn't accept numbers with decimals correctly. 


Changes from 1.4 to 2.0:





  After closing of the About form sometimes the wrong Tab was opened.

  Max number of decimals didn't work as intended.

  Copy Actual Value on Properties form worked only if Clipboard was empty.

  Actual Value less than 1 on Properties form didn't show leading 0.

  Several tabs didn't set focus to any box after returning from Standard Values.

 Inserting a decimal point first in an existing number did not add leading zero.


dB, %, X:

  Altering between Voltage and Power at high dB numbers show invalid number.


Voltage Divider:

  Runtime Error if rightclick on empty R and no unknown selected.
 When turning off Standard Values and "R1 AND R2" where unknown the "R1 AND R2" box was locked.
 Using standard values while unknown is "R1 or R2" shows standard values on both, should be only one.

  When unknown is "R1 AND R2" Standard values are still enabled if R1 + R2, U or U1 is cleared.
 If U, U1 and R1 or R2 was defined and "R1 AND R2" were selected no calculation was done on entries.
 "Wrong value" label not cleared when R1 or R2 box was cleared.
 Standard Values could be selected after any R-box had been cleared when R1 + R2 was unknown.


Serial Resistors:

  Runtime Error on if rightclick on empty R and no unknown selected. 

  Run Time Error when Unknown is "R1 AND R2" and calculated Standard Values were transferred to R1 and R2

  Set Decimals Form could be opened even when Standard values was used.


Parallell Resistors:

 Returning from calculated Standard Values on "R1 AND R2", i.e. selecting R or R1, whith valid numbers in all boxes didn't enable

    Standard Values until one value was changed.

C Impedance & L Impedance:

 True values of TR, CZ and LZ could be slighly wrong due to calculations using too few deciamls. 





 Method to open the "Set Decimals" form changed.


PI-net & T-net:

  Checkbox to copy values between PI and T changed so it has to checked before switching tab and is also cleared when tab is changed.
     Checkbox status also not saved anymore and it is disabled while standard values are shown.
 Resistor values changed to show non prefixed numbers e.g.1230 rather than 1.23k.


C Impedance & L Impedance:

  Added  Frequency prefix for GHz.





  Added noninverting OpAmp and inverting OpAmp tabs.

  Added a Properties form showing the actual values of all number boxes. Values could be copied and/or saved to file.

  Added a Help form showing Key strokes and Mouse clicks. Opens with <F1> or Right click on a free space on any tab.
 New Key Strokes and Mouse Clicks to open the various forms.
 All forms except the main form can be closed with <Esc>.

  Increased the number of decimals options.

 A lot of code changed and all calculations are now made with maximun number of decimals. 


dB, %, X:

  Changed upper limit dB from 100 to 120 dB.


Changes from 1.3 to 1.4:


PI-net & T-net: 


 T Net inputs didn't accept decimals.

  Standard values could be selected when Attenuation had been cleared resulting in a Run Time Error.
 Attenuation Label missing.

  Run Time Error if Standard Values was selected and one resistor was marked as open.

  R1-R3 values could be cleared with double click, now are locked.
 Reverse attenuation could be cleared with double click, now are locked.
 Some Z settings caused a false "Incorrect Value" message e.g. 400 & 300.
 Clear All didn't return focus to any text box now return to last selected.

  Z1 or Z2 could be cleared with double click while Standard Values a were active causing locked tab.

  Togling between actual and Standard Values when one resistor is less than 1 ohm results in wrong values on both actual and Standard Values.


 Input R, Output R and Attenuation values from PI Net transferred to T Net and vise versa if the appropriate Check box is ticked.
 Button to recalculate Min Attenuation added.
 R values < 0.1 ohm now shown as Short and value >100M are shown as Open while calculations use the actual values.



  Toggling between Voltage and Power with valid attenuation value always calculated Min Atenuation.

    Now if the Attenuation box is empty Min Attenuation is calculated otherwise the current Attenuation is used to calculate resistors. 

  Setting decimals now possible on all text boxes.





  dBm, dBU, dBV: One option label said V instead of W.

  dBm, dBU dBV: "Value too high or too low"-message cleared all entries

  dB, %, X: Swap between Voltage and Power did not set focus to any textbox if the textbox was empty.

  Voltage Divider: U1 unknown, Incorrect value warning if U is cleared and R1 or R2 is changed.
 Voltage Divider: Standard resistor values less than 100 showed too many decimals.

  Parallel Resistors: Decimal settings wasn't disabled when using Standard values.


  ALL: Actual values now used for all calculations on all tabs as opposed to the formatted values shown in the text boxes. 

  ALL: Function of Delete key changed to delete all in a text box only when Shift + Delete is pressed so normal function of the Delete key

    i.e delete only selected characters or the one character to the right of the cursor.

  ALL: Changed how standard values are calculated e.g. actual values are used to calculate rather than the box numbers.

  ALL: Right click to open windows calculator changed to double click 

  L Impedance: Impedance default prefix opions changed to the same as C Impedance.



  ALL: About form open by right click on a free space on any tab. 

  ALL: copy button added to "Set Decimals" form to copy the actual value to clipboard.
 Resistor Power: Added Standard value on R and changed how labels are shown.

Changes from 1.2 to 1.3:



   Serial Resistor (New in v1.1) didn't get a keyboard shortcut (Alt S).

   Entering a number greater than 7 in octal box on Convert Number tab caused Run Time Error.


    Capacitance Impedance added on Tab 10.
    Inductance Impedance added on Tab 11.

    All tabs now open  with focus on the first textbox.

    Tab stops on text boxes and Clear All buttons.

    Delete key on all textboxes clears the textbox, same as double click.
    Space bar on textboxes selects corresponding option if textbox is empty.

Changes from 1.1 to 1.2:



   Calculated actual values added to Result drop down lists of Parallel Resistors and Serial Resistors.

    (On previous versions the drop down lists contained only R1, R2 and percentage).


Changes from 1.0 to 1.1:



   Canceling save text file on Parallel Resistors saved file anyway.
   Using standard values on Parallel Resistors always indicated R1 as no standard value even if it was.
   Sys Rise Time value did not initially show the correct number of decimals.
   Changing Unknown from R1 and R2 on Parallel Resistors cleared all entries.

   The word Resistor was spelled wrong in the header of the saved text file of Parallel Resistors.



    / on Parallel Resistor list changed to //
    Zero value added to Percent selection on Parallel resistors.



   Serial Resistors added on Tab 9.
   Added function to open windows calculator, right click on free space on any tab.
   Icon to main form.


Version 1.0

  Initial version.


Here's screen shot of one tab::



The number of decimals shown can be set invidually on every numbers box.
  <F1> or Right Click on a free space on any tab will show available Key Strokes and Mouse Clicks.


Download Various Calculations here
To update an earlier version either uninstall the older before running install or replace the VarCalc.exe file in your
Program Files(x86) folder with the one in the zip file.


Hope I've done the math right on all tabs but if not or you have suggestions about any other calculations that
can be added Email me with comments  /Hkan

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