Toroid Calculator

A free, open-source calculator for toriod inductors, baluns, ununs, etc.

 home: ky8d.net/free 

Introduction    ↑   → 

Easy way to vet various toroids for suitability. Play with any variable while program re-calculates continuously in a loop.

List of Features     ←   ↑   → 

• Calculates on-the-fly. No tedious single-run button to re-press over and over.
• Obtain any feasible impedance ratio.
• Watchdog with pop-up for rule-of-thumb about the Low-Z winding’s min/max turns count.
• If wanting only a toroid inductor (not a transformer), then just ignore the High-Z side.
• Built-in User Guide
  • Startup default is example 9:1 using Fair-Rite 5943002701 (Amidon FT140-43 equivalent).
  • Scrolling text box with how-to information.
  • Right-Click any widget, choose Description and tip for explanation.

Manual Checking     ←   ↑   → 

Below I show 50 turns wound through two different toroids, with an LCR meter set to 10kHz measuring the inductance. The OEM spec sheet will give a value of A_L in some sub-unit of Henries for a given number of turns.

Mix 61, Spec 170nH/turn ± 25%

Mix 68, Spec 16nH/turn Min

Fair-Rite makes it easy giving their A_L in nH/turn. Amidon complicates things by specifying their A_L as uH/100turns. Just remember that inductance is factored upon the square of turns.

References     ←   ↑   → 

Here are links to websites on the same topic. The top two are OEM sources for toroids.

•  Fair-Rite 
•  Amidon 
•  Homebrew Balun & Unun 
•  Cromwell International 
•  Low Power Balun 

Download     ←   ↑   → 

You’ll need two things for it to run: my *.exe application itself, plus also the interpreter program on which it runs. Kind of like Java that way, except that the Java interpreter is probably pre-installed on your system. The LabVIEW run-time engine will not be.

1. Download 1st:  LabVIEW Runtime Engine 
   • This is the interpretor program.
   • Or, should it please you, the entire LabVIEW programming environment.
   • Link back to ky8d.net/free where I give download instructions.
2. Download 2nd:   ZIP  
3. Important! Best to employ a stand-alone ZIP archive software (like  7-Zip ) for extracting the *.exe file. Otherwise, Windows will issue dire warnings of an unrecognized app. Once extracted from out of its archive, however, Windows will know to pass it off to the LabVIEW Run-Time Engine instead.
4. Source Code, for any who want it.
   • Do with my LabVIEW code just as you please. Credit me or not as you choose. Do please pass along any credit I’ve given to other sources.
   •  Source  The LabVIEW source code.

Caveat Mutuum     ←   ↑ 

Latin for “Let the moocher beware”. I designed this for me, and used it with glee. I share it here with you for free, but offered without even so much as the smell of a dead warrantee (or wheriot, as the case may be). Whatsoever disasters of cosmic proportion as may result from the use of this program, any and all culpability rests wholly and solely with the user.