Interesting Patent: Tesla

Body

Hi Lutz,
It takes certain amount of energy to magnetise the core of a transformer
allowing for losses & inefficiencies in the core etc.
In DC and alternating circuits, input power is worked from Volts x Amps.
(without mentioning power factor).
In AC circuits both the input Volts and the Amps alternate between positive
and negative.

When we multiply Volts times Amps, if both are positive we get positive
answer or if both Volts and Amps are negative we also get positive answer.
If we can introduce a time delay to either the Volts or the Amps, so that
one of them is Negative whilst the other is still Positive. Then the +ve
Volts x -ve Amps will give a negative answer.

If input power calculation is Negative it means the flow of power is
reversed and the load is supplying power to the power source. A sort of
Negative resistance effect.

Tesla's method was to introduce this delay by placing layers of insulated
fine steel wire between primary and secondary windings (at right angles).

It takes a certain time for each layer of Iron wire to become fully
magnetised and the primary flux, has to fully saturate each layer before
being transmitted to the next Iron wire layer.

Eventually the primary input flux caused by the primary input current
reaches the secondary winding and induces an output Voltage.
Giving Tesla the times delay he was after.

The load then starts to draw it's own current creating it's own magnetic
field but it also has to negotiate the Iron wire layers to get back to the
Primary.
And by this time the phase of the input Volts has already reversed
direction.

Gerry