Hand Wound Inductors for crossover networks.

[pranavkumar]

Hey Folks !

I'm relatively new to this forum, this being my first post
Alright,
SO, on 15th of august i decided to keep down my kites and get to some work ! I'm currently building a two-way transmission line speakers for a friend, for which i needed crossover networks. I decided to make them myself, and figured that the first order ones would be good enough. That also saves me the pain of winding two more coils..
After some research i finally got to work and made a jig to "Hand Wire" the coils. Using a 18Gauge wire was not the greatest of ideas, because of the high recoil force for it is pretty thick !
I will post some pictures of how i made the jig and wound the inductors !

This is the link :
https://plus.google.com/photos/1119...ms/5777295727919180081?authkey=CIa28_yPydreEw

 

[pranavkumar]

Here are some of the pictures from the same album !

 

[bijinmb]

I saw the image. better automate that work by using DC motor and our old cassette deck counter. it can really count the no. of turns irrespective of the motor speed. make a mechanism which can swing back and forth guiding the coil in the jig.

Hand winding is tiresome, time consuming and prone to errors and moreover boring job.

Even the motor you find in the old cassette deck is good enough for winding the coil with applied tension. But need to do some gearing which is simply putting a bigger diameter wheel in the target flywheel and a very small wheel in the motor section.

 

[svenkateshsmart]

Great efforts! It is really hard to accomplish this task manually. Looking forward to seeing more.

 

[sbg]

I saw the image. better automate that work by using DC motor and our old cassette deck counter. it can really count the no. of turns irrespective of the motor speed. make a mechanism which can swing back and forth guiding the coil in the jig.

Hand winding is tiresome, time consuming and prone to errors and moreover boring job.

Even the motor you find in the old cassette deck is good enough for winding the coil with applied tension. But need to do some gearing which is simply putting a bigger diameter wheel in the target flywheel and a very small wheel in the motor section.

I'm afraid, the motor in old cassette deck will just stop the moment you switch on. The motor should have more Torque to do this kind of job(winding 18swg copper wire!)

 

[bijinmb]

That is why i have recommended to use gearing. I just pointed a cheaper option. Better is always use a motor which is having a decent torque for the required wire gauges so can avoid gearing and drive directly and when needed speed regulation, do that by regulated voltage supply.

 

[pranavkumar]

@Bijin. yes its a good option, but the cassette deck motor is not powerful enough ! Even after a small gear box, the torque cannot be enough ( Saying by experience, pulling a 18swg wire and winding at the same time).

a better option would be to get hold of a drill machine, and make a mount kind of a thing that would fit into the bit holder and attaching a fan regulator with the mains, to control the speed.
The only task here would be to hold the drill machine in place, but that would still be better than winding on a PVC pipe !

 

[pranavkumar]

@svenkateshsmart
Thanks a ton, will definitely put up pics of a few more projects i'm working on

 

[pranavkumar]

Finally, i took out some time to build the crossovers ! i used a 3mm MDF board for building the crossovers. I'm trying fan capacitors which are easily available in the market. These are metalized polyester i believe.

Here are all the pictures :
https://plus.google.com/photos/1119...ms/5777295727919180081?authkey=CIa28_yPydreEw

 

[vivekkumar]

Good effort Pranav, I'm sure the final outcome viz response and SQ would be good too! all da best

 

[photoprashanth]

I too wanted to wind my own inductors. Only problem I had was turns counter which I solved by using my android phone. There are some proximity counters available for free in android market place. I just needed to place my phone near the spool of my coil winding jig and use a piece of sponge to move close to the proximity sensor once every turn. It counts like a charm.

-Prashanth

 

[quad]

I too wanted to wind my own inductors. Only problem I had was turns counter which I solved by using my android phone. There are some proximity counters available for free in android market place. I just needed to place my phone near the spool of my coil winding jig and use a piece of sponge to move close to the proximity sensor once every turn. It counts like a charm.

-Prashanth

Cool. Here is another simple solution -

Untitled Document

 

[pranavkumar]

I too wanted to wind my own inductors. Only problem I had was turns counter which I solved by using my android phone. There are some proximity counters available for free in android market place. I just needed to place my phone near the spool of my coil winding jig and use a piece of sponge to move close to the proximity sensor once every turn. It counts like a charm
-Prashanth

Never thought of that! Thanks a lot, next time I'll make use of the application.

 

[pranavkumar]

Cool. Here is another simple solution -

Untitled Document

That's so awesome.

 

[koushik]

I know this is an old post but still ...
@Pranavkumar - How was the final outcome of this xover - with hand wound inductors and fan capacitor?

 

[pranavkumar]

I know this is an old post but still ...
@Pranavkumar - How was the final outcome of this xover - with hand wound inductors and fan capacitor?

It was good. did its job well. the inductor proved its significance, but i have my doubts on how accurate they were.
the fan capacitor too served well. the highs were brilliant. I didnt put a L-Pad network, which i highly recommend for high sensitivity tweeters.

Since i dont own the speakers for which these XOs were made, i didnt get a chance to do the optimizing part, which is very very much necessary for XOs.

 

[koushik]

Thanks! The value of fan capacitors available is very narrow. I only managed to get a 2 & 2.5 uF only in local electrical store. Are you aware if other values are available or not?

At 2.5 uF it will cross near 12 kHz which is not much useful.

From where did you source the copper wire? Do you have any reliable source of good quality copper wire?

 

[bhaskarcan]

Thanks! The value of fan capacitors available is very narrow. I only managed to get a 2 & 2.5 uF only in local electrical store. Are you aware if other values are available or not?
............................

Hi Koushik,

Locally these also called 'motor starter' capacitor. There are big range and varieties available in Kolkata Chandni market. I've bought frm 1uf to 10uf, but other values are also there. Price depends on the company. But normally very cheap.

...............
From where did you source the copper wire? Do you have any reliable source of good quality copper wire?

For copper wire go to the next lane of main Chandni market towards Wellington. There are many shops selling copper wire, varnish etc. anything related to motor coil. You can also get your coil wound up there to your specification. Or you can buy a simple hand winding zig. When buying copper wire buy the imported quality which has better coating then their local counterpart.

Regards,

Bhaskar

 

[koushik]

Thanks bhaskarcan. That is very helpful. Will visit Chandni this Saturday.

 

[koushik]

Went there and found the place. The capacitor was easy picking as I always guessed and it made my tweeter sounding as if I have replaced them with something double their price. Rs. 32 worked wonder for them.

But I couldn't able to manage the inductors. The coil wire available there, they measure them using SWG and not our known unit AWG. I don't know what will be SWG equivalent of 18 AWG or so. Can anybody help?