Noise pulse cancellation system formed by a pair of transformers

Claim 3

A noise pulse cancellation system for a device having applied to an input of said device a current pulse and having produced at an output of said device an output voltage pulse and a noise pulse comprising cancellation transformer means having a primary circuit connected to said input and a secondary circuit connected to said output whereby said current pulse applied to said input produces said voltage pulse, said noise pulse and a single noise cancellation pulse in said output, said cancellation transformer means comprises a first and a second transformer, said first transformer having a first primary winding and a first secondary winding, said second transformer having a second primary winding and a second secondary winding, said first primary winding in series circuit with said second primary winding defining said primary circuit, said first secondary winding in series circuit with said second secondary winding defining said secondary circuit, said first transformer having a first core of magnetic material movable with respect to said first windings thereby to vary the magnetic coupling between said first core and said first windings and said second transformer having a second core of substantially highly conductive and highly magnetic material movable with respect to said second windings thereby to vary the magnetic coupling between said second core and said second windings, and said first transformer being very close to said second transformer to provide an effective single resultant transformer whereby the magnetizing inductance of said resultant transformer is adjusted by moving said cores thereby to change the timing and amplitude of said single cancellation pulse to coincide in time and amplitude with said noise pulse.

Claim 4

A noise pulse cancellation system for a device having applied to an input of said device a current pulse and having produced at an output of said device an output voltage pulse and a noise pulse comprising cancellation transformer means having a primary circuit connected to said input and a secondary circuit connected to said output whereby said current pulse applied to said input produces said voltage pulse, said noise pulse and a single noise cancellation pulse in said output, said cancellation transformer means comprises a first and a second transformer, said first transformer having a first primary winding and a first secondary winding, said second transformer having a second primary winding and a second secondary winding, said first primary winding in series circuit with said second primary winding defining said primary circuit, said first secondary winding in series circuit with said second secondary winding defining said secondary circuit, said first transformer having a first core of magnetic material movable with respect to said first windings thereby to vary the magnetic coupling between said first core and said first windings and said second transformer having a second core of substantially highly conductive and highly magnetic material movable with respect to said second windings thereby to vary the magnetic coupling between said second core and said second windings, and said first transformer being very close to said second transformer to provide an effective single resultant transformer whereby the magnetizing inductance of said resultant transformer is adjusted by moving said cores thereby to change the timing and amplitude of said single cancellation pulse to coincide in time and amplitude with said noise pulse.

Claim 5

The noise pulse cancellation system of claim 2 in which said first primary winding is disposed very close to said second primary winding and said first secondary winding being disposed very close to said second secondary winding thereby providing negligible separation between said first and second primary windings and between said first and second secondary windings.

Claim 6

The noise pulse cancellation system of claim 3 in which said device includes a first and a second input terminal and a first and a second output terminal, said primary circuit being connected between said first input terminal and said device input and said secondary circuit being connected between said first output terminal and said device output.

Claim 7

The cancellation system of claim 2 in which said second core (1) has a permeability of substaNtially high magnitude as compared with said first core and (2) is formed having a maximum eddy current flow at the beginning of the rise time of said current pulse and saturating rapidly as said current pulse increases.

Claim 8

The cancellation system of claim 5 in which said second core is of hollow cylindrical shape having a cross section at right angles to the lines of flux produced by said second windings.

Claim 9

The cancellation system of claim 4 in which said first and second windings are disposed very close to said device whereby the electrical connections between said first and second windings and said device are substantially short thereby to decrease any delay times therebetween.

Claim 10

The cancellation system of claim 2 in which there is provided a single printed circuit board having a first opening for receiving said first core and a second opening for receiving said second core, at least one conductive strip on a first surface of said board being arranged adjacent to and around said openings to form said first and second primary windings, at least one conductive strip on a second surface of said board arranged adjacent to and around said first and second openings to form said first and second secondary windings.