choke for the power supply

Status
Not open for further replies.
Jump to Latest
#2
choke air core?

interesting question...i remeber i posted it once without any reguarding answer.

Let's see.

I actually need a air choke 2.2mH (with no more than 0.38mohm) that can handle 25-30A.

I remember somebody suggesting me to build one bymyself... it could be a suggestion as well 🙂
 
#7
Is there any air core choke that can handle 22-25A?

As far as i know air core, compared with iron core has a better sound eather used on the loudspeaker filter, output zobel network or power supply clc filter....or whatever.

I just would like to know if there are chokes with this specifics o if it's possible to make chikes like that....i would personally prefer to find something well made personally 😀 :angel:
 
#8
Stefanoo said:
Is there any air core choke that can handle 22-25A?

As far as i know air core, compared with iron core has a better sound eather used on the loudspeaker filter, output zobel network or power supply clc filter....or whatever.
Click to expand...

are you saying one can use speaker inductors in power supplies?

There are different kinds of chokes/inductors. And I believe you can't just use one type can be applied for another application.
 
#10
Sure an air core can handle 25A if the wire gauge is big enough. The trouble starts when you want to buy such off the shelf.....that is as far as I know a "no can do" situation.

I have made quite many such powerfull inductors, they're big, and very expensive these days, as the copper price has trippled over the last couple of years.

So if you feel like letting go of like at least 80 EUR a piece, keep searching for a manufacturer, otherwise just go for a couple of the toroid chokes from apex.jr in parallel.

Magura 🙂
 
#11
After initially thinking of going for CRC on a mini aleph, I've decided to go for CLC -- will get some 12awg magnet wire and roll my own approx 2.2mh air core inductors.
The PSU will be running 2 channels, each biased at 2A -- meaning to prevent the inductor getting too hot I'd need at least 14awg.

here is a calculator for making inductors

Jarthel -- why do you need 35A current handling??? That seems quite a lot?

Also, could anyone give some insight into how air chokes should be mounted shielded in an amp?


OT again:

Netlist said:
Nelson gave his blessing for the Kristjan boards.
Click to expand...


GRollins said:


(...)
Click to expand...

considering there are still a lot of people buying these boards, perhaps this issue needs to be sorted out once and for all, one way or the other -- because very obviously it hasn't been. Perhaps the mods can split this thread off and help sort it out.
 
#12
Yes, you should always shield air core inductor/choke. This kind of inductor usually generate a lot of EMI.

You need a cooper foil or cooking alumunium foil (if you can't find cooper foil), wrap around the inductor, and solder it to ground
 
#15
Magura said:
Sure an air core can handle 25A if the wire gauge is big enough. The trouble starts when you want to buy such off the shelf.....that is as far as I know a "no can do" situation.

I have made quite many such powerfull inductors, they're big, and very expensive these days, as the copper price has trippled over the last couple of years.

So if you feel like letting go of like at least 80 EUR a piece, keep searching for a manufacturer, otherwise just go for a couple of the toroid chokes from apex.jr in parallel.

Magura 🙂
Click to expand...

It would be fine to me to spend 80eur for each inductor.
The more i think and the more i would like the idea of making them on my own.
Obviously i don't understand the issue yet.

But i like the idea to have the possibility to choose the kind of copper to use for the choke....like litz or some goog stuff.

Moreover by choosing a good copper with low resistence, the choke would have a low DRC which it would be super usefull in the specific case where there are 22A going on on the main power supply circuit.

Have you ever had the possibility to compare one of your own made choke with a commercial good one?

If so, what are the differences between the two of them?
 
#16
Stefanoo said:


It would be fine to me to spend 80eur for each inductor.
The more i think and the more i would like the idea of making them on my own.
Obviously i don't understand the issue yet.

But i like the idea to have the possibility to choose the kind of copper to use for the choke....like litz or some goog stuff.

Moreover by choosing a good copper with low resistence, the choke would have a low DRC which it would be super usefull in the specific case where there are 22A going on on the main power supply circuit.

Have you ever had the possibility to compare one of your own made choke with a commercial good one?

If so, what are the differences between the two of them?
Click to expand...


Well, to start with your last question, yes I have compared my inductors with commercial inductors. The commercial inductors are humming away frequently, mine are dead silent.

As for the kind of copper, yes it's nice to have a choice, but your parameters are way off. The parameters of interest are:

1) Cross section
2) Quality and max. temperature of the enamel
3) How you fixate the inductor after winding
4) How tight the lay-up is.


All the bull about OFC and litz....you name it, makes ZIP difference for and inductor in this application.

In this case "good" copper is well known brand names of heavy gauge copper. Synflex comes to mind.

Today a spool of copper will set you back like 400-500 EUR.

Magura 🙂
 
#20
Stefanoo said:
nice!

Just a couple curiousity.

What do you need to make a coil like that?

Do you need a special machine?

How do you wing, twist, wrap the copper such to form a toroid shape?

How long does it take to make one of that coil?
Click to expand...


http://www.briangt.com/gallery/magura-inductors

Here you can see some of the tools you need to make exactly such an inductor as I made for Steenoe.

Yes you need a lathe or the like. Something with low revs and quite a bit of power, in order to make the windings lay reasonably even and tight.

The inductors get the shape of the winding-tool, so the tool is the key here.

To make a decent tool will take you a few hours and a nice big chunk of aluminum. Once you have made the tool you can wind the inductors in like half an hour a piece. Again, the tool is the key.
This is naturally depending how big an inductor you have to wind. The big ones from the link, are like a days work to make one.

For 25A you will also have to impregnate the inductors to keep them silent, so a special heat resistant polyesther enamel is a must.

Besides that, all you need is to get some practice, it takes a few attempts to get a reasonable result.

Magura 🙂
 
Status
Not open for further replies.
Top Bottom