Help with Coil Winding for Water Fuel Cell Circuit

[shovel52]

I am trying to gather some info about winding inductors. This is not simple. I am trying to put together a resonant circuit to power a water fuel cell. I know a lot of people will say that this is bull but I don't care , I am having fun with it and am learning a heap. The circuit uses a bifilar choke. The specs on the choke are

2x190 turns of 5/10mm magnet wire #24 on a 20mm cardboard tube 190 mm in length

he says this is a 240 mh coil "I am assuming he means mili henrys"

I have posted 2 links at the bottom of the page. One is to the water fuel cell designer and the other is to an inductance calculator.

I have input this gentlemans specs. on his inductor into the inductance calculator and I get
133 micro henrys. Unless I am doing something wrong, something is wrong.
Please have patience here I do have a back ground as an electronics tech but I am a beginner on the design work.

There is a big difference on inductance here. I have wound a similar choke using 1/2 inch pvc pipe and 200 turns of #22 wire. I bought a cheap inductance meter off of ebay and have hooked it to one side of the inductor, and I get a reading of 1.9 on the 20 milihenry range
and 3 on the 200 milihenry range. The meter has no over range function like an ohm meter , all it does is move the decimal point. So I have no idea the value of my inductor?
I would assume it would be close to his at 246 mh?
I have seen math equations for calculating inductance but no one uses examples. Examples are the only way people can learn. but you don't see any. Would anyone here have any input? Ideas or examples to calculate the inductance of this mans inductor? thanks John

http://jnaudin.free.fr/wfc/index.htm

http://www.66pacific.com/calculators/coil_calc.aspx

 

[AndyW]

Dear John,

Thank you for reaching out with your questions about winding inductors. It is great to hear that you are having fun and learning a lot in the process. I understand that there can be some confusion when it comes to calculating inductance, but I am here to provide some guidance and clarification.

Firstly, I would like to address the discrepancy in the inductance value you calculated for the bifilar choke. The inductance calculator you used may not account for the fact that the wire is bifilar, meaning it is wound in two parallel wires instead of one. This can affect the inductance value, so it is important to use a calculator or formula that accounts for this type of winding.

Additionally, the material of the core (in this case, a 20mm cardboard tube) can also affect the inductance value. The calculator you used may not have an option to input the type of core material, so it is possible that the calculated value is not accurate for your specific setup.

I would recommend using a more comprehensive inductance calculator or formula that takes into account the bifilar winding and core material. Here is an example of a calculator that allows you to input these variables: https://coil32.net/pcb-coil-inductance-calculator.html. It may also be helpful to consult with other experts or forums in the field of electronics to get a second opinion and more resources.

In terms of your own inductor, it is difficult to determine the exact inductance value without knowing the specifics of the winding and core material. However, your reading of 1.9 on the 20 millihenry range and 3 on the 200 millihenry range suggests that the inductance is somewhere in between those two values. It is always best to use a more precise measuring device, such as an LCR meter, to get an accurate reading.

I hope this information helps and wish you the best of luck with your water fuel cell project. Science is all about experimentation and learning from it, so don't be discouraged by any setbacks. Keep exploring and asking questions, and you will continue to learn and improve. Good luck!

 

[sir-pinski]

Hi John,

Thank you for reaching out for help with your coil winding for the water fuel cell circuit. It sounds like you have been doing a lot of research and experimentation, which is great! It's always exciting to learn new things and try out new projects.

Firstly, it's important to note that calculating inductance can be a complex process and there are many factors that can affect the final value. It's possible that the difference in inductance between your inductor and the one specified by the water fuel cell designer could be due to variations in the wire used, the core material, or even the accuracy of the inductance meter.

That being said, here are a few suggestions to help you troubleshoot and potentially improve the accuracy of your inductance measurements:

1. Make sure your inductor is wound correctly. A common mistake when winding inductors is to have overlapping or unevenly spaced turns, which can affect the inductance value. Make sure to wind the wire tightly and evenly along the entire length of the core.

2. Double check the wire gauge and core material. The wire gauge and core material can have a big impact on the inductance value. Make sure you are using the same wire gauge and core material as specified by the water fuel cell designer.

3. Use a more accurate inductance meter. It's possible that your inductance meter is not very accurate, especially since it doesn't have an over-range function. Consider investing in a more precise meter or borrowing one from a friend or colleague.

4. Use an online calculator. As you have already done, using an online inductance calculator can help give you an idea of the expected inductance value. However, keep in mind that these calculators are only as accurate as the information you input, so make sure you have the correct specifications for your inductor.

5. Experiment with different number of turns. If you are still having trouble getting the desired inductance value, try experimenting with different number of turns and see how that affects the inductance. This will help you get a better understanding of the relationship between turns and inductance.

Overall, it's important to remember that inductance calculation is not an exact science and there can be variations in the final value. Keep experimenting and learning, and don't be afraid to reach out for help or advice from others in the electronics community. Good luck with your project!