Coil Calculator (Version 2.0)

[Qiaozhi]

Unfortunately I must admit to finding a couple of bugs in the previous version of my coil calculator.

If you downloaded the previous version, then please replace it with this one. It's written with a mixture of HTML and Javascript, and you just need to load coilcalc.htm into your favorite browser.

You will now find the inductance calculation to be more accurate, and is much closer to the real value.

Please let me know if you find it useful.

[simonbaker]

Unfortunately I must admit to finding a couple of bugs in the previous version of my coil calculator.

If you downloaded the previous version, then please replace it with this one. It's written with a mixture of HTML and Javascript, and you just need to load coilcalc.htm into your favorite browser.

You will now find the inductance calculation to be more accurate, and is much closer to the real value.

Please let me know if you find it useful.

Excellent, thanks. A good one is very useful. When I make a round coil I'll test it.

-SB

[nakky]

Unfortunately I must admit to finding a couple of bugs in the previous version of my coil calculator.

If you downloaded the previous version, then please replace it with this one. It's written with a mixture of HTML and Javascript, and you just need to load coilcalc.htm into your favorite browser.

You will now find the inductance calculation to be more accurate, and is much closer to the real value.

Please let me know if you find it useful.

Thanks Qiaozhi,but the prevous version is more accurate to my experiments with DD coils .Grt Nakky.

[Qiaozhi]

Thanks Qiaozhi,but the prevous version is more accurate to my experiments with DD coils .Grt Nakky.

The old version has a couple of major errors. It is just lucky that it's working correctly for you. It is designed for circular coils, but you are reforming the coil into a D shape.

It would be better to use the new calculator, and then measure the inductance after bending into the D shape. This will give you an idea of the percentage reduction in inductance between the two shapes. If for example there's a 10% reduction, then simply aim for an inductance value that's 10% higher when using the calculator.

[nakky]

When I have to make new coils I will try it,thanks .Grt Nakky.

[WM6]

Super, but regret not work under my Firefox (apper frozen entry form).

[Qiaozhi]

Super, but regret not work under my Firefox (apper frozen entry form).

I am using Firefox and it works fine. It has been tested with IE, Firefox, Google Chrome, Epiphany and Sea Monkey. Also tested on both Windows and Linux.

Check to see that your browser has Javascript support and ActiveX enabled.

[simonbaker]

I tested with a homemade coil and I think it is better than last version, but still maybe 10% too low. However I don't trust my memory of number of turns on the coil so I'll try to check with some other coils.

Thanks for making it available!

-SB

[Qiaozhi]

I tested with a homemade coil and I think it is better than last version, but still maybe 10% too low. However I don't trust my memory of number of turns on the coil so I'll try to check with some other coils.

Thanks for making it available!

-SB

There were two bugs in the original version. The first was a stupid mistake in the calculation of the mean radius. This calculation is based on the number of turns, wire thickness, and inner radius. Hindsight is a wonderful thing, and now it's so glaringly obvious to me, when I look at the calculated value, that I've no idea why it wasn't spotted earlier. The second bug concerned the accidental use of Log-base10 instead of natural logs.

I think the reason the bugs were not found earlier is because of the size of coils we are all using. By pure luck the two bugs had opposite effects, and the final inductance calculation, for that size coil, gives believable results. Initially I found the first bug, and that caused a dramatic change in inductance, which led me to discovering the second one.

As they say: "To really screw up, you need a computer."

[nakky]

Qiaozhi you are right,second one is more accurate .Grt Nakky.

[nakky]

80 / 0.28 / 130 =7.147

[simonbaker]

80 / 0.28 / 130 =7.147

That's a pretty cool looking coil form, can you tell us about it?

-SB

[Qiaozhi]

Qiaozhi you are right,second one is more accurate .Grt Nakky.

80 / 0.28 / 130 =7.147

If you were to bind the windings with tape, it would cause the inductance to increase further. In that case the two values would be even closer.
I think the calculator is now working perfectly.

Thanks for the feedback.

[nakky]

That's a pretty cool looking coil form, can you tell us about it?

-SB

Simon ,my english is poor,maybe my pics are better.Grt Nakky.

[simonbaker]

coil winder

Simon ,my english is poor,maybe my pics are better.Grt Nakky.

Ha ha ha! That is dream come true!!! Very excellent!

I have not found a way to quickly "bind" the coil with thread -- it is slow.

I can use plastic "zip-ties", fast and easy, but too thick and cost money.

I need a special way to tie a good tight knot with thread quickly many times.

Nice machine!

-SB