# help to make an inductor!!!

Discussion in 'Homework Help' started by Nelson2001, Nov 11, 2011.

1. ### Nelson2001 Thread Starter Member

Nov 10, 2011
27
0
I have to make an RL (SERIES)circuit in a breaboard, but after making the inductor, the voltage is proportonial to the resistence....
This is 12AC 60HZ, 150ohms variable resistor, and
the voltage is always proportional this is 6vols in resistence, 6 volts in inductance,.... 8 volts in resistence, 4 volts in inductance....

With RC(SERIES)circuits it's was very fine, exactly what i read. The XC Voltage was what I expected.

There is a way to contruct a single inductor???. I make a lot with ferrite core & iron core but obviously there is a mistake.
THKS.

Last edited: Nov 11, 2011
2. ### Georacer Moderator

Nov 25, 2009
5,151
1,266
Can you post your circuit, along with the voltage source you have?

I 'm not sure I understand what your problem is.

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3. ### t_n_k AAC Fanatic!

Mar 6, 2009
5,448
783
To make an inductor with a reactance equal (say) to the series resistance (150Ω??) would mean you need to wind an inductance of ~400mH. That could be difficult with small ferrite cores. What cores are you using?

And keep in mind, whatever inductance you make will have winding resistance. For the same wire gauge, the greater the number of turns required to achieve your inductance value then the greater the winding resistance.

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4. ### Nelson2001 Thread Starter Member

Nov 10, 2011
27
0
Sending you pictures of failed RL circuits........ The internal resistence of inductor(relay), is 385OHMS(DC), Uunder AC 12V 50HZ, is 485/500ohms(linear values), Variable resistor 500 OHMS.
Changing variable resistor (and measure voltage) the inductor acts like another resistor, never drops 12volts.... In RC, series circuit no problem.

Last edited: Nov 11, 2011
5. ### thatoneguy AAC Fanatic!

Feb 19, 2009
6,357
718
Inductors for 60Hz will be physically large if they are to handle any amount of current.

What is the overall project? We may have a better solution than the one you are trying currently.

If you are just learning about inductors and an LR voltage divider, drive it with a function generator at 1kHz+ so inductors will be smaller.

6. ### Nelson2001 Thread Starter Member

Nov 10, 2011
27
0
The little project is a RLC resonance, in series & //. I make all the maths, phasor, phase angle reactance (inductive)...
I do not have a Function generator. Neither scope
I have 220/12v AC 50HZ transformer. The electronics simulator, orcad, multisim, etc.
Have hundreds of copper wire. Ready to build another one. but I tired. Guess U right. The Skin effect?. Have to learn thks.

Dec 26, 2010
2,147
300
Skin effect is unlikely to be such an issue for small coils working at mains frequency. The skin depth reduces with frequency.
The basic internal series resistance of the coils is another matter.

With air-cored coils or relatively low permeability ferrite cores, the inductive reactance is likely to be quite small at such low frequencies compared to their resistance. In other words, their "Q" is likely to be very low: Q = (Reactance)/(Series Resistance).

As a previous poster has advised, this kind of experiment is more conveniently carried out at higher frequencies.