Combined inductive and flux-responsive transducer

Claim 2

A combination inductive and flux-responsive magnetic transducer for both reading and writing magnetic signals, comprising: permeable means spaced to define a flux pickup gap therebetween: a flux-responsive element having a first output circuit; said permeable means being arranged to place said fluxresponsive element in series magnetic circuit with said flux pickup gap; an inductive winding about one of said permeable means which is also in series magnetic circuit with said same flux pickup gap; a second output circuit for connection to said winding; a magnetic signal wriTing circuit for driving said winding; and switching means for connecting said winding alternatively to said writing circuit or to said second output circuit.

Claim 3

In a combination transducer for detecting at least one varying signal, of the type including an inductive transducer means for producing an electrical output proportional to the time differential of a flux, magnetoresistive transducer means for producing an electrical output proportional to the instantaneous value of a flux, an output circuit connected to respond to both said transducer outputs, and means arranged to pick up and conduct a signal flux, said inductive transducer means comprising at least one winding inductively coupled to said flux-conducting means and connected to said output circuit, said magnetoresistive transducer means being interposed in said signal flux conduction path whereby to sense the same magnetic signal as said winding, said flux-conducting means comprising a pair of pole pieces spaced to define a flux pickup gap therebetween, said winding encircling at least one of said pole pieces, said magnetoresistive transducer means comprising at least two magnetoresistive elements interposed between said pole pieces to sense the flux picked up in said gap, and magnetic biasing means comprising at least two permanent magnets and permeable means for conducting the flux of said magnets through said two elements in respective opposite directions to aid and oppose said signal flux respectively in its effect on the resistance of said elements; the improvement wherein: respective ends of said pole pieces extend away from said flux pickup gap and into spaced relationship with each other; said permeable means is a substantially T-shaped member having a center leg and opposed side legs, said center leg thereof being interposed between said spaced pole piece ends; each of said magnetoresistive elements is interposed between a respective one of said pole piece ends and said center leg of said T-shaped member; and each of said permanent magnets is interposed between a respective one of said side legs of said T-shaped member and a respective one of said pole pieces; whereby said signal flux passes in a single instantaneous direction through said pole pieces, said magnetoresistive elements, and said center leg; while said permanent magnet flux splits off from said center leg to pass in opposite directions through respective magnetoresistive elements, pole pieces, and side legs.

Claim 4

In a combination transducer for detecting at least one varying signal, of the type including an inductive transducer means for producing an electrical output proportional to the time differential of a flux, magnetoresistive transducer means for producing an electrical output proportional to the instantaneous value of a flux, an output circuit connected to respond to both said transducer outputs, and means arranged to pick up and conduct a signal flux, said inductive transducer means comprising at least one winding inductively coupled to said flux-conducting means and connected to said output circuit, said magnetoresistive transducer means being interposed in said signal flux conduction path whereby to sense the same magnetic signal as said winding, said flux-conducting means comprising a pair of pole pieces spaced to define a flux pickup gap therebetween, said winding encircling at least one of said pole pieces, said magnetoresistive transducer means comprising at least two magnetoresistive elements interposed between said pole pieces to sense the flux picked up in said gap, and magnetic biasing means comprising at least two permanent magnets and permeable means for conducting the flux of said magnets through said two elements in respective opposite directions to aid and oppose said signal flux respectively in its effect on the resistance of said elements; the improvement wherein: respective ends of said pole pieces extend away from said flux pickup gap and into spaced relationship with each other; said permeable means is a substantially T-shaped member having a center leg and opposed side legs, said center leg thereof being interposed between said spaced pole piece ends; each of said magnetoresistive elements is interposed between a respective one of said pole piece ends and said center leg of said T-shaped member; and each of said permanent magnets is interposed between a respective one of said side legs of said T-shaped member and a respective one of said pole pieces; whereby said signal flux passes in a single instantaneous direction through said pole pieces, said magnetoresistive elements, and said center leg; while said permanent magnet flux splits off from said center leg to pass in opposite directions through respective magnetoresistive elements, pole pieces, and side legs.

Claim 5

A combination transducer and circuit for use as a speed control for a magnetic record transport mechanism comprising: an element for producing an output which is a function of the rate of change of a signal; an element for producing an output which is a function of the instantaneous value of said signal; a transport mechanism for producing relative motion between a recording medium and said combination transducer whereby said combination transducer scans at least one signal recorded on said medium; means for controlling the scanning speed of said transport mechanism in response to a control signal; and an output circuit arranged so as to develop a signal which is a function of the difference between said two element outputs, and to apply said difference signal to said speed control means as said control signal to govern the speed of said transport mechanism.

Claim 6

A combination transducer and circuit for use as a speed control for a magnetic record transport mechanism comprising: an element for producing an output which is a function of the rate of change of a signal; an element for producing an output which is a function of the instantaneous value of said signal; a transport mechanism for producing relative motion between a recording medium and said combination transducer whereby said combination transducer scans at least one signal recorded on said medium; means for controlling the scanning speed of said transport mechanism in response to a control signal; and an output circuit arranged so as to develop a signal which is a function of the difference between said two element outputs, and to apply said difference signal to said speed control means as said control signal to govern the speed of said transport mechanism.

Claim 7

A combination transducer and circuit for use as a speed control for a magnetic record transport mechanism; comprising: an inductive element for producing an electrical output proportional to the time differential of a flux; an element for producing an electrical output proportional to the instantaneous value of a flux; a circuit connected to respond to both said element outputs; a transport mechanism for producing relative motion between a magnetic recording medium and said combination transducer whereby said combination transducer scans at least one magnetic signal recorded on said medium; and means for controlling the scanning speed of said transport mechanism in accordance with an electrical signal; said output circuit being so arranged as to develop a signal which is a function of the difference between said two element outputs, and to apply said difference signal to said speed control means to govern the speed of said transport mechanism.

Claim 8

A combination transducer and circuit for use as a speed control for a magnetic record transport mechanism; comprising: an inductive element for producing an electrical output proportional to the time differential of a flux; an element for producing an electrical output proportional to the instantaneous value of a flux; a circuit connected to respond to both said element outputs; a transport mechanism for producing relative motion between a magnetic recording medium and said combination transducer whereby said combination transducer scans at least one magnetic signal recorded on said medium; and means for controlling the scanning speed of said transport mechanism in accordance with an electrical signal; said output circuit being so arranged as to develop a signal which is a function of the difference between said two element outputs, and to apply said difference signal to said speed control means to govern the speed of said transport mechanism.