Controllable transformer

A method for controllable conversion of a primary alternating electrical signal to a secondary alternating electrical signal using a controllable transformer comprising a body of a magnetic material, a primary winding wound round the body about a first axis, a secondary winding wound round the body about a second axis at right angles to the first axis, and a control winding wound around the body about a third axis, coincident with the second axis, the method comprising the steps of:

• supplying the primary winding with the primary alternating electrical signal;
• supplying the control winding with an alternating voltage which is shifted in phase relative to the primary alternating electrical signal by one of 0° and 180°;
• and
• supplying the control winding with a variable current,
• wherein a conversion ration of the transformer is controlled by the variable current.

A method for controllable conversion of a primary alternating electrical signal to a secondary alternating electrical signal by a controllable transformer comprising a magnetic material having magnetic domains, the method comprising the steps of:

• supplying a primary winding with a primary alternating signal;
• supplying a control winding with an alternating voltage which is shifted in phase relative to the primary alternating signal by one of 0° and 180°;
• adjusting the amplitude of the alternating voltage to change at least one of domain directions in the magnetic material and a magnetization angle between the primary winding and a secondary winding;
• introducing an inductance in a control circuit;
• and
• adding an electromagnetic force from the secondary winding to an electromagnetic force from the control winding;
• whereby a voltage transfer of the transformer is changed,
• whereby the magnetization angle between the primary winding and the secondary winding is influenced by the added electromagnetic force,
• whereby an effect of a direct transformative connection between the secondary winding and the control winding is suppressed,
• whereby a phase angle rotation between the primary winding and the secondary winding varies according to load conditions,
• whereby the phase angle rotation is compensated for, and
• whereby a controlled transformation effect is achieved by obtaining a primary winding response to a load change in a secondary load.

A method of aligning domains in a magnetisable core of a transformer, the transformer comprising a first winding, a second winding, and a third winding wherein the first winding and the second winding are oriented orthogonal to one another, the method comprising the steps of:

• energizing the first winding;
• monitoring a current in the first winding;
• monitoring a current in the second winding;
• and
• exciting the third winding to compensate for domain changes established by the second winding.

A method of controlling the orientation of a field in a transformer, the method comprising the steps of:

• generating a primary field in a first direction;
• generating a secondary field in a second direction orthogonal to the first direction;
• generating a control field in a third direction which is coincident to the first direction;
• and
• adjusting the control field to control a direction of the primary field.