US 3594672 A
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United States Patent  Inventor Amotz Frenkel Lansdale, Pa.  Appl. No. 840,776  Filed July 10, 1969  Patented July 20, 1971  Assignee Transducer Systems, Inc.
Willow Grove, Pa.
 TRANSDUCER DEVICE 5 Claims, 2 Drawing Flgs.  U.S. C1 336/132, 336/170, 336/183  Int. Cl 1Hl0ll2l/06  Field of Search 336/130, 136,132,170,17l,188,182,183;323/48,49
I56] References (Zited UNITED STATES PATENTS 929,256 7/1909 Sink 336/170 X 1,251,208 12/1917 Ferriter 336/170 X 1,732,937 10/1929 .lones..... 336/188 X 2,374,930 5/1945 Gray 323/48 X 2,461 ,238 2/1949 Schaevi tz. 336/136 2,482,471 9/1949 Dowell 336/136 X 2,558,573 6/1951 Manke 336/136 X 3,138,772 6/1964 Persons, .lr. 336/130 X Primary Examiner-Thomas J. Kozma Attorney-Jacob Trachtman ABSTRACT: A transducer device having a primary winding, a plurality of secondary windings and a core electrically coupling the secondary windings with the primary winding. The secondary windings comprise a plurality of insulated wires bundled together and wound as a helical winding so that when an input signal is applied to the primary winding a separate output signal is induced in each of the secondary windings.
TRANSDUCER DEVHCE The present invention relates to a transducer device, and more particularly to a transducer having a plurality of output signals.
Transducers in general comprise a primary winding, a secondary winding and a core electrically coupling the primary and the secondary windings. Thus, when an electrical current is applied to the primary winding, an output signal is induced in the secondary winding. A proximity transducer is constructed so that when a metal object is moved toward the end of the core of the transducer the output signal will vary even 'though the input signal is maintained constant. Such proximity transducers can be used as switches to provide a signal when a piece of metal, such as an operating key, is moved toward the core of the transducer.
For certain types of electrical equipment it is desirable to provide a plurality of output signals to operate a plurality of separate functions by the operation of a single actuator key. This has been previously achieved by using diode matrix circuits. However, such circuits take up considerable space, are expensive because of the number of electrical components required, and are time consuming to assemble in production of the electrical equipment. Therefore, it would be desirable to have a single switching means which would provide a pl urality of output signals upon the actuation of a single operating key.
It is therefore an object of the novel transducer device which output signals.
It is another object of the present invention to provide a proximity transducer which will produce a plurality of output signals when a piece of metal, such as an operating key, is moved into proximity with the core of the transducer.
These objects are achieved by a transducer having a primary winding, a secondary winding and a core electrically coupling the primary winding and secondary winding. The secondary winding comprises a plurality of wires bundled together and electrically insulated from each other.
For the purpose of illustrating the invention there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.
FIG. 1 is a sectional view of an embodiment of the transducer device of the present invention.
FIG. 2 is a circuit diagram of the transducer device.
Referring to FIG. I, the transducer device ll) of the present invention comprises a cylindrical bobbin 12 of an electrical insulating material, such as a plastic or ceramic. The bobbin 12 has a hole 14 extending longitudinally therethrough along the axis thereof, and three longitudinally spaced grooves l6, l8 and in its outersurface. A primary winding 22 of an insulated electrically conductive wire is helically wound around the bobbin 12 in each of the end grooves 16 and 20. A secondary winding 24 is helically wound around the bobbin 12 in the center groove 18. The secondary winding 24 comprises a plurality of separate electrically insulated wires 26 bundled together, such as by twisting them together along their length. The bundle of the wires 26 is then helically wound around the bobbin. A core 28 of a magnetic material is within the hole 14 in the bobbin 12. The core 28 extends across the primary present invention to provide a produces a plurality of separate other of said windings winding 16 and the secondary winding 24, but is offset from one end of the bobbin 12 so as to project from the other end of the bobbin.
In the use of the transducer device 10, the primary winding 22 is connected to a source of electrical current. The current passing through the primary winding 22 creates a magnetic field. The core 28 electrically couples the secondary winding 24 with the primary winding 22 so that the magnetic field created by the primary winding induces an electrical voltage in each of the wires 26 of the secondary winding 24. Thus, there is produced a separate output signal in each of the wires 26 of the secondary winding.
en a metal member, such as an operating key 30, is moved close to the end of the core 28, the magnitude of the output signal from each of the secondary winding wires 26 will vary, and can be made to increase. Thus, the output signal from each of the wires 26 can be switched from a low value to a high value. By connecting each of the wires 26 of the secondary winding 24 to a separate mechanism to be controlled, a single transducer 10 can be used to simultaneously operate a plurality of mechanisms. Although the transducer 10 is shown as having five wires 26 in the secondary winding 24, it has been found that it can include as many as eight wires and still provide satisfactory switching signals from each wire. Also, although the transducer 10 is shown as having the secondary winding in the center and the primary winding split on each side of the secondary winding, the primary winding can be in the center with the secondary winding being split on each side of the primary.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.
What I claim is:
1. A transducer device comprising a primary winding for receiving an input signal, a secondary winding, a fixed core of magnetic material electrically coupling the primary winding and the secondary winding, said secondary winding including a plurality of separate wires which are bundled together and insulated from each other so that a plurality of separated output signals are provided from a single input signal, and a key member of metallic material secured for being moved with respect to said core for switching the output signal of each of said wires from a lower value to a higher value.
2. A transducer device in accordance with claim 1 including a cylindrical bobbin of an electrical insulating material, the primary winding and the secondary winding being wound around the bobbin and the core extending through the windings.
3. A transducer device in accordance with claim 2 in which the bobbin has a hole extending longitudinally therethrough along its axis and the core is within said hole.
4. A transducer device in accordance with claim 3 in which the bobbin has a plurality of annular grooves in its outer surface and each of the windings is wound in a separate one of said grooves.
5. A transducer device in accordance with claim 4 in which the bobbin has three annular grooves in its outer surface, one of said windings being wound in the center groove and the being wound partially in each of the end grooves.