US2567116A

US2567116A - Magnetic frequency changer having partial gaps

Info

Publication number: US2567116A
Application number: US163043A
Authority: US
Inventors: Harold J Mccreary
Original assignee: Automatic Electric Laboratories Inc
Current assignee: Automatic Electric Laboratories Inc
Priority date: 1950-05-19
Filing date: 1950-05-19
Publication date: 1951-09-04
Anticipated expiration: 1968-09-04

Description

Sept. 4, 1951 H. J. M CREARY 2,567,115

MAGNETIC FREQUENCY CHANGER HAVING PARTIAL GAPS Filed May 19, 1950 Fl G. l

2 ff 10 Y:: 0,@

O 0 J 3? INPUT FIG. 2

o r o INIBUT INVENTOR. HAROLD J. M CREARY ATTORNEY Patented Sept. 4, 1951 MAGNETIC FREQUENCY PARTIAL G CHANGER HAVING APS Harold J. McCreary, Lombard, Ill., assignor to Automatic Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware Application May 19, 1950, Serial No. 183,043

4 4 Claims. (01. 321-68) This invention relates in general to frequency changers which utilize saturated ferromagnetic cores to produce an alternating current having a frequency which is a harmonic or sub-harmonic of the frequency of an alternating current source; and in particular to improvement in the construction of the magnetic core and the arrangement of electrical circuits of such irequency changers.

An object of the present invention is to provide a frequency changer utilizing a magnetic cross valve in which a partial gap is inserted to create Odd harmonics.

Other objects and features will appear upon a further perusal of the specification taken in conjunction with the accompanying drawing which illustrates several embodiments of the invention in the form of schematic circuit diagrams.

Fig. 1 is a diagrammatic representation of the frequency changer having intersecting partial gaps in the center of the magnetic cross valve core.

Fig. 2 is a diagrammatic representation of a frequency changer having partial gaps extending diagonally from two intersecting members of the magnetic cross valve core.

In the present invention two coils are wound through opposite diagonal corners of the magnetic cross valve so that there is no mutual inductance between the respective coils. However. when the magnetic core reaches a degree of saturation a difierential flux is set up to induce a voltage in one of the coils. A partial gap is used in th magnetic cross valve core to emphasize the odd harmonic rather than the even harmonic which would be caused by D. C. saturation.

Referring now to Fig. 1 which shows a magnetic cross valve l. The magnetic cross valve I herein used may be of the type disclosed in Patent No. 2,445,857, issued on July 27, 1948.'to the present inventor and also in Patent No. 2,461,992, issued on February February 15, 1949, to the present inventor. Primary winding 2 is shown diagonally wound through a pair of oppo'site corners of the intersecting members of the magnetic cross valve l. Secondary winding 3 is wound through another pair of diagonal corners of the intersecting members or the magneticcrossvalve I andisdispIacedbyQOdegrees from the primary winding. The result, therefare, is that there is no mutual inductance between the respective coils until the magnetic core has reached a degree 01' saturation. A condenser t is included in the secondary circuit to tun the A partial gap 9 is shown at the center of the magnetic cross valve core-l and is positioned in a plane parallel to that of the primary winding and extends in a direction from one corner to the opposite diagonal corner. Another partial gap I0 is shown at the center of the magnetic cross valve core I and is perpendicular to the partial gap 9. The partial gap In extends between the other pair of diagonal corners from which partial gap 9 is extended. The function of the partial gap is to emphasize the odd harmonics. In magnetic circuits the gap will have a different flux density than the metallic core structure. Therefore, at a degree of saturation, a differential flux is set up at the center of the magnetic cross valve to induce a voltage in the secondary winding.

An input alternating current voltage is fed to the primary winding 2. The current flow in the primary winding produce an alternating flux in the core I. A voltage is induced in the secondary winding Sin a manner previously described. The output signal of the secondary winding is an odd harmonic.

Referring now to Fig. 2 which shows a magnetic crossvalve 5. The magnetic cross valve 5 herein used may be of the type disclosed in Patent No. 2,461,992, issued on February 15, 1949, to the present inventor and also in Patent No. 2,445,857,

issued on July 27, 1948, to the present inventor.

A primary winding 6 is wound through a pair of opposite diagonal corners of the magnetic cross valve 5. A secondary winding 1 is wound through the opposite pair of diagonal corners of the magnetic cross yalve 5 and is displaced degrees from the primary winding. A condenser I2 is included in the secondary circuit to tune the secondary circuit to the desired output frequency. A partial air gap 8 is shown extending in a diagonal direction from the lower left-hand corner of the intersection to a point of close proximity to the-center of the magnetic cross valve 5. Another partial gap H is shown extending downward from th upper right-hand corner of the intersection and is extended in close proximity to the center of the magnetic cross valve core 5. The partial gaps shown in Fig. 2 are eflective on only one winding in much the same way as superimposed D. C. flux would be effective on only one winding. It is therefore possible to produce 20 cycles from a 60 cycle input or it is possible to produce cycles from a 60 cycle input. The

desired output frequency is produced by changing the size of the condenser I! so as to tune the secondary circuit to the desired odd harmonic.

secondarycircuittotbedeliredoutputi'requency. u ThepartialgapsinFig.2alsoemphasizetheodd harmonics, when a degree of saturation is reached in the magnetic core 5. The partial gaps will produce a flux differential to induce a voltage in the secondary winding I, since the flux density of the air gap is different form the flux density of the ferromagnetic substance used to form the core of a magnetic cross valve 5. The operation is similar to that described in referenc to Fl .1.

although I have described my invention with a certain degree of' particularity, it should be understood that the present disclosure has been made only by way of example and that numerous changes in the details of construction and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.

What is claimed is:

1. In a frequency changer, a magnetic core structure having two intersecting members, a primary winding wound through opposite diagonal corners of the intersection, a source of current for energizing said primary winding to provide the input signal, a secondary circuit tuned to the desired output signal and wound through the other opposite corners of said intersection, and said magnetic core having partial gaps at the general area of core saturation to provide a flux differential in said core whereby an alternating current is induced in said secondary circuit having a frequency which is integrally related to the frequency of said source.

2. In a frequency changer, a magnetic core structure having two intersecting members, a primary winding wound through a pair of opposite diagonal corners of the intersection, a source of current connected to said primary winding for providing an input signal, a secondary circuit tuned to a desired odd harmonic and wound through the other pair of opposite comers of said intersection, and said magnetic cor having partial gaps intersecting at the center of said magnetic core to provide a flux difierential in said core whereby an alternating current is induced in said secondary circuit having a frequency which is an odd harmonic of the jrequency of said source.

3. In a frenquency changer, a magnetic core structure having two intersecting members to form opposite diagonal corners, a primary winding wound through a pair of opposite diagonal corners of the intersection, a source of current connected to said primary winding for providing an input signal, a secondary winding tuned to a desired harmonic and wound around said magnetic core so as to be at right angles to said primary winding, an output circuit connected to said secondary winding, and said magnetic core having partial gaps extending from a pair of opposite diagonal corners to provide a flux differential in said magnetic core whereby an alternating current is induced in said secondary winding having a frequency which is integrally related to the frequency of said source t be delivered to said output circuit.

4. In a frequency changer, a magnetic core structur having intersecting members, a primary winding wound through opposite diagonal cornersof the intersection, a source of current for energizing said primary winding to provide the input signal, a secondary circuit tuned to the desired output signal and wound through the other opposite corners of said intersection, said magnetic cores having partial gaps angularly disposed with respect to said intersecting members at the intersection of the core members to provide a flux differential in said core whereby an alternating current is induced in said secondary circuit having a frequency which is integrally related to the frequency of said source.

HAROLD J. MCCREARY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,118,935 Joly Dec. 1, 1914 1,731,616 Flehr Oct. 15, 1929 2,309,586 Haines Jan. 26, 1943 2,455,078 McCreary Nov. 30, 1948