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Ctrl_r to rotate an inductor

Sam Jesse
 

Hi

What effect to inductor/transformer building does Ctrl_r mean in the physical sense?
In the example of Files/Temp/ transformer.asc
L1, L2 and L3. how can I build this home transformer project to "play" with?i.e. how to wind it to match the LTspice design?

Thank you
John Woodgate
 

In message <CAK-wn_6=bn+xLOd_mBp9qofHnHq+39rP=WLhM8V0BH5DLuJ+XA@...>, dated Mon, 26 May 2014, "Sam Jesse revrvr@... [LTspice]" <LTspice@...> writes:

In the example of Files/Temp/ transformer.asc
L1, L2 and L3. how can I build this home transformer project to "play" with?i.e. how to wind it to match the LTspice design?
That is a VERY big question, and nothing to do with simulation. The inductance values, with 1000:1 ratio, you show are hardly feasible for a practical transformer (except a toroid with a single-turn primary - that *might* work). K = 0.9 is difficult to achieve with a transformer having a magnetic core. 0.98 would be more practicable, and it hardly affects the simulation.

Is the transformer supposed to work with the pulse input of 1.5 V and no load on the output other than the capacitor? The voltage applied and the current output determine the core size and winding area you need. It looks as though a ferrite toroid is your best choice but you need quite a big one to get 100 mH twice. I doubt you can get enough design guidance on the web; you really need a very good textbook.
--
OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk
Nondum ex silvis sumus
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
Sam Jesse
 

Hi
The point which I was most concerned about is the fact that L3 is "rotated" unlike L1 and L2.

Thank you


On Mon, May 26, 2014 at 3:57 PM, John Woodgate jmw@... [LTspice] <LTspice@...> wrote:

?

In message
WLhM8V0BH5DLuJ+XA@...>,
dated Mon, 26 May 2014, "Sam Jesse revrvr@... [LTspice]"
<LTspice@...> writes:

>In the example of Files/Temp/ transformer.asc
>L1, L2 and L3. how can I build this home transformer project to "play"
>with?i.e. how to wind it to match the LTspice design?

That is a VERY big question, and nothing to do with simulation. The
inductance values, with 1000:1 ratio, you show are hardly feasible for a
practical transformer (except a toroid with a single-turn primary - that
*might* work). K = 0.9 is difficult to achieve with a transformer having
a magnetic core. 0.98 would be more practicable, and it hardly affects
the simulation.

Is the transformer supposed to work with the pulse input of 1.5 V and no
load on the output other than the capacitor? The voltage applied and the
current output determine the core size and winding area you need. It
looks as though a ferrite toroid is your best choice but you need quite
a big one to get 100 mH twice. I doubt you can get enough design
guidance on the web; you really need a very good textbook.
--
OOO - Own Opinions Only. With best wishes. See
Nondum ex silvis sumus
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
John Woodgate
 

In message <CAK-wn_4VATz=nfQ0uy+hDJTvqE2M2fqVdhLesuQoksSN_x9STA@...>, dated Mon, 26 May 2014, "Sam Jesse revrvr@... [LTspice]" <LTspice@...> writes:

The point which I was most concerned about is the fact that L3 is "rotated" unlike L1 and L2.
The orientation in the schematic means nothing in real life. Only the 'polarity dots' have any significance, indicating the north (or south) poles of the magnet the inductor and its current produce.
--
OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk
Nondum ex silvis sumus
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
 

The end with the "dot" does make a difference. ?If you rotated or mirrored an inductor on the LTspice schematic so that the "dot" swapped locations with respect to the rest of the circuit, that would be the same as either (a) swapping the leads on that particular winding, or (b) winding it in the opposite direction (counter-clockwise rather than clockwise).

Of course, rotating an inductor while leaving its ends connected the same as before, changes nothing. ?Hopefully you knew that already.

The convention of using "dots" on transformer windings has been around for decades. ?You should find information about it going back a very long time ... probably to before any of us was born.

Andy

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