Although Nikola Tesla was know for his work with Alternating Current he neverless saw the need to convert his so beloved AC into DC and suggested the following idea,.The diagram he used to explained it, is in fig 1
Basically it consists of an alternating Power supply feeding to to two DC battery banks connected in opposite polarity.,
The power supply in these batteries would need to match the voltage and current level of the alternating A.C.of the particular value of a half sine wave value.
One branch of the DC circuit would offer a high resistance to the Alternating power supply and the other side would offer a lower resistance , in a similar way as diode full wave bridge rectifier would work today.
In Fig 2 below there is a further enhancement of his idea in using two ring transformers
The idea is for the dc power supply the green battery is so to saturated the magnetic core and to prevent additional
magnetic energy to be stored in the field surrounding the transformer.
However if a pulse is applied of opposite polarity this will decrease the magnetic strength and thus allowing current and power to flow for one half of the AC cycle.
It seems to me if we could do away with the need to use a DC source power to saturate the core and use permanent magnets in a way as shown in figure 3 we may be able to achieve a magnetic rectifer using the setup below.
The P/Magnets would need to match and be held into place against a modified "I" type metal lamination in a setup as above to force the two separate magnetic fields through the centre portion of the metal lamination and cause magnetic saturation of the entire metal component of this special modified transformer
A coil of winding is so calculated as to match the magnetic strength of this saturation and will only allow current and voltage to flow when the power causes a decrease in magnetic strength of the modified transformer for one half of an AC sine way.
The whole set up would need to be held firmly in place because an opposing magnetic field would probably force the unit appart.
It also occurs to me a similiar results could be obtained from Fig 4 and Fig5, although I don't think it would work as well
as the design in Fig3 even thought they would be easier to construct and experiment with.
I believe the designs would not be cost effective for low power requirements as I belive solid state devices are quite capable of handling this need ,but for very high power and free energy research the above device may full fill a need especially in relationship to Hans Coler devices and such like..