inductors (electronic)

[ybwuser]

Are they all the same.

I mean, if rated the same, do they do the same job as a physically different looking type.

Does a wire wrapped toroid do the same as the ones here:

http://www.rapidonline.com/searchresults.aspx?style=0&kw=inductor

Thanks in advance

 

[lw395]

Apart from inductance, important characteristics are DC resistance, Self-Resonant Frequency (above which they sort of don't work), saturation current (above which they sort of don't work), Q- a measure of how narrow a filter you can build with them.
Wire wrapped toroids have the advantage of low coupling with other bits of circuit becaue the magnetic field is contained in the toroid.
Hope that helps.
What are you trying to achieve?

 

[DaveS]

You give few clues in either your post or your profile, but I'll venture a reply. If two inductors have the same rating for both inductance (mH) and current carrying capacity (A) then they should be electrically identical. This does, however, assume that a reasonably low frequency is contemplated, since at high frequencies the geometry starts to matter, and inductance of the leads etc. may become significant. It would help if we knew more about what you want your inductor to do.

 

[William_H]

As already suggested there are many factors in describing an inductance. They are available over a huge range of inductance resistance etc.

I would take guess that you want to isolate electrical interference coming in on a power line in your boat.
So primary concern is DC resistance because typically anything over 1/10 ohm will give a volt drop of significance. (Volt drop is current multiplied by resistance.)

Second thing is the actual inductance. The effect it has to appear as a resistance (choke) to high frequency interference depends on the frequency. So Impedance XL (apparent resitance) is given as equal to 2pi freq times inductance (in Henries)
This might give you an idea of the amount of inductance you need. Inevitably large inductance at low DC resistance are big ie usually iron cored. The ferrite rings will give a small inductance which if coupled with a capacitor will give an effective barrier to interference of a higher frequency.
ie inductance to provide a block and capacitor for a bypass.
Capacitive impedance is 1 over 2pi FC
good luckk olewill

 

[ybwuser]

Wow, thanks for these 3 replies guys.

I have no idea what it is for. I was trying to help out a very very oldfashioned mate.

He wouldn't know how to turn a computer on (although he could probably fix one) , but is a whizz (as it appears you guys are too) with electronics. Probably boaty, but he spends more time in his 'shed' (very nice workshop actually) than he does on the water.

I asked him what he was doing the other day (wire everywhere)He said he was making an inducer by wrapping wires around a toroid and I said can't you just buy some from rapid - he said who's rapid, etc.

I will pass on your wisdom - he will make more sense of it than me - he does a lot of radio stuff, so maybe it is that? I will have to find out, but knowing him he has finished and is on to the next project - very nice bloke when it comes to helping me out with techy things.
Thanks again.

 

[Billjratt]

I think he was making a balun for an antenna, or some other wide-band transformer. Sound like my kind of guy.