Патент USA US2411810код для вставки
Patented Nov. 26, 1946 2,411,810 UNITED STATES PATENT OFFICE 2,411,s1o AUDIO REAUI'QR Morris Sander, Philadelphia, Pa, asslgnor to Radio Corporation of America, a. corporation of Delaware Application September 20, 1943, Serial No. 503,054 1 7 Claims. My present invention relates to a reactor for use at audio frequencies, the inductance of which it is desired to vary over a predetermined range. In practice it has been found dif?cult to obtain adequate inductance change in high Q, low-fre quency inductors. In one application of the pres ent invention, operating at about 939 cycles per second, I have been able to obtain an inductance variation of :l;Ll5%, the Q of the coil being be tween 30 and 35. (Cla I'll-“242). 2 l which are rectangular in cross-section. The ‘ three compartments are open-ended at the top and bottom, are aligned with one another, and disposed in parallel relation. The central com“ partnoent which is extended somewhat above and below the two end compartments, as shown more clearly in Fig. 4, is adapted to receive an iron core made of compressed iron dust, the core be ing sliclably adjustable within the compartment Ml 5 by means to ‘be hereinafter described. The two end compartments" 6, ‘l are each is made adjustable and comprises a coil form oi adapted to receive the center leg 9, Si’ of a com insulating material having a central and two end posite ?xed core M3 constituted by stacks of lami compartments which are open-ended, in align nations which may be of Numetal (a niclzel alloy) ment and disposed in parallel relation. A coil of or other suitable material. For convenience of wire is wound around the coil form in a direction assembly the ?xed laminated core it is made of transverse to the direction of the compartments, two similar parts it and it’ which are paired, and a ?xed laminated iron core having an air as shown more clearly in Fig. 3, to provide the gap ‘is positioned within each of the end com center leg d, 9', the portions of which are adapted partments. There is further provided within the to be inserted into an end compartment from op central compartment a powdered-iron core which posite sides and to be positioned in ?tted spaced is capable of adjustment relative to the coil and relation to provide an air gap iii’ between them. air-‘gaps of the ?xed cores for the purpose of In order to maintain the pair of laminated varying the inductance of the reactor. The novel features characteristic or" my inven~ 25 cores ill in ?xed parallel relation and also to rigidly retain in position the two parts M, ii’ of tion are set forth with particularity in the ap~ each. core there is provided at each end a clamp“ pended claims. The invention itself, however, ing plate 92 to which a pair of brackets l3 are both as to its construction and mode of opera spot welded or otherwise attached. The two tion together with the objects and advantages brackets of each clamping plate are properly thereof, will best be understood by reference to spaced and are adapted to embrace the corre the following description taken in connection sponding sides of the two ?xed cores it, and by with theaccompanying drawing in which means of four screws it the oppositely disposed Fig. 1 is a plan view to scale of the reactor as~ In accordance with the invention, the reactor 'sern‘cly in accordance with the invention; Fig. 2 is a front elevational view of Fig. 1; Fig. 3 is a view in cross-section taken along the - line 3-3 in Fig. 1, showing the two-part fixed laminated core; Fig. 4i is a cross-section taken along the line il-d in Fig. 1; . Fig. 5 shows the complete assembly of the re actor enclosed in a casing; Fig. 6 is a detail view of the core adjusting means, and ,7 represents the schematic circuit of the reactor. Referring to Fig. l the reactor comprises an inductance winding or coil 5 which is wound, in a plane parallel to the surface of the drawing, clamping plates it‘ are held together. Each plate is provided with a ?ange or foot portion i5 for convenience or" attachment by means of screws, rivets or otherwise to a base plate it (Fig. 5). The base plate to has attached to it a pair of terminals ll, ll’ to which the leads 3, d from the inductance coil l are connected. A suitable rec tangular-shaped metal can housing to is ?tted over the entire assembly and is soldered or other wise connected to an upturned flange it of the base plate it. The can housing is provided at its two shorter sides with a pair of flanges or foot portions ill for attachment to a chassis or other mounting, and is further provided in its upper wall with an opening through which there is passed a screw shaft 26 which is adapted to slid- ‘ ably adjust the iron core 8 within the center around a centrally located spool or coil form 2. 50 compartment 5 of the coil form 2. The coil leads are indicated at 3 and It. The The iron dust core 8 is also square-like in cross spool '2 may be of moulded nylon or other suit able insulating material and is provided with a central compartment 5, square-shaped in cross section, and two similar end compartments 6 and section and is provided with a centrally located bore 22 which extends for about three-quarters of the length of the core from the bottom. The remaining portion of the core above the bore is 2,411,810 internally threaded and is adapted to ride on the screw shaft. Frictionally within the bore and positioned near the lower end thereof is a nut plate Or retaining member 23 through which the screw shaft_is also threaded. A compression as a magnetic shield to con?ne the magnetic ?ux between them. ' While I have shown and‘rdescribed a preferred ' embodiment of my invention, it will be under spring 25 is concentrically arranged around the shaft within the bore and extends between the nut plate and the opposing internal rim portion of the core in orderlto take up any play ‘or back stood that various modi?cations and changes will ' occur to those skilled in the art without depart; ing from the spirit and scope of this invention. I therefore contemplate by the appended claims to cover any such modi?cations as fall within the 10 true spirit and scope of my invention. ‘ lash between the core and the screw shaft. What I claim is: In order that the adjustable core may be ac 1..A reactor comprising a coil form of insulat curately centered within its compartment there ing material having a, central and two end com is utilized a block member or plug 25 formed with partments, said compartments being open-ended, an aperture 28 within which the lower end of the screw shaft is adapted to be seated. The 15 centering block is suitably attached by screws, rivets, or the like, to the cover plate i8, is simi larly shaped in cross-section as the center com-i in alignment and disposed in parallel relation, a coil of wire wound around the coil form in a direc tion transverse to the direction of the compart ments, a ?xed laminated iron core extending into each of the end compartments, and an adjustable partment, and is of su?icient length to extend powdered-iron core extending into the central, into said compartment at the lower end and to 20 compartment. be snugly ?tted therein. ‘2. A variable reactor for audio frequencies com= In order that the. core may be adjustably set from the outside of the can housing, the latter prising a coil form of insulating material having a central and two end compartments which are disposed in parallel relation, a coil wound around is provided in its top'wall with an aperture it’ through which there extends an externally 25 the coil form in a direction transverse to the threaded bushing 21!, the intermediate portion of direction of the compartments, a ?xed iron core which is provided with a ?rst disc member 36 and extending into each of the end compartments, a second‘ larger disc member 30’. The two disc members may form an integral part of the bush ' said fixed cores each having an air gap located in the field of the coil, and a powdered-iron core or otherwise mounted thereon, as by means 30 adjustably movable within the central compart of a forced ?t. The larger disc 3%’ is concentri ment for varying the inductance of the reactor. cally arranged with respect to the housing aper 3. A variable reactor for audio frequencies com ture it’ and is soldered to the top wall of the \ prising a coil form of insulating material having housing. By means of a washer 28 and a locknut ‘ a central and two end compartments, said com . ing, 29, the bushing and its associated parts are clamped in position. The bushing is adapted to receive within its bore the upper unthreaded end of the screw shaft 25 which is retained therein and confined only to rotary motion by means of partments being open-ended, in alignment and disposed in parallel relation, a coil of wire wound around the coil form in a direction transverse to the direction of the compartments, a ?xed lami nated iron core provided with an air gap extend a C washer 3i engaging a circumferential groove 40 ing into each of the end compartments, and an 32 in the shaft. A washer 33 and a spring washer adjustable powdered-iron core ‘movable within 3d are interposed between the C washer and the the central compartment capable of varying the bushing in order to lock the shaft against verti inductance of the reactor. cal movement. For effecting the desired adjust 4. A variable reactor in accordance with the ment of the core, rotation of the screw shaft by invention de?ned in claim 3 wherein the reactor means of a suitable tool, such as a screw /driver, is housed within a container provided with an will cause the core to ride up or down depending aperture which is aligned with the central com upon the direction of shaft rotation. An inter partment and through which there is adapted to nally tapped cap 35 may be provided to ?t over the 59 extend the means for adjusting the powdered exposed end of the bushing on which the screw iron core. head is seated to prevent tampering after an 5. A reactor comprising a coil form of insulat adjustment has been made. ing material having a central and two end com In one embodiment of the invention the coil partments said compartments being open-ended, consisted of 1,000. turns of wire, the air gap in 55 in alignment and disposed in parallel relation, a each ?xed core was 311", and the adjustable core coil of wire wound around the coil form in a di was 1" ‘in length and .594" square. With the rection transverse to the direction of the com adjustable core 8 all the way in (Fig. 5) and a partments, a pair of three-limbed laminated iron source of voltage at the input terminals of the cores having their respective central limbs ex reactor of 1 volt and a frequency of 1,000 cycles, 60 tending into one of the end-compartments and the inductance was approximately 0.47 henry, their outer limbs positioned externally of the whereas with the core all the way out, the in ductance was approximately.0.36 henry, an in vcoil, and an adjustable powdered-‘iron core ex tending into the central compartment. ductance change of approximately 30%,' or 6. A variable reactor for audio frequencies com 115% from a mean core adjustment giving 0.415 ” prising a coil form of insulating material having a central and two end compartments which are henry. The inductance change is due to the fact that the powdered iron dust core varies the in ductance not only by acting on the turns of the coil but also by short circuiting the air gaps‘o'f the ?xed core stacks. ‘ In contradistinction to the usual reactor ‘as semblies employed in radio apparatus, the in . ductance and the Q of the reactor of the present disposed in parallel relation, a coil wound around the coil form in a direction transverse to the di rection of the.compartments, a pair of three limbed iron cores having their respective central limbs extending into one of the end compart ments and their outer limbs positioned exter nally of the coil, each of said cores constituting a closed magnetic circuit except for an air gap invention are not affected by the can housing for 75 in the central limb located in the ?eld of the coil, the reason that. the ?xed laminated cores act‘ 2,411,810 and‘ a powdered-iron core adjustably movable . within the central compartment relatively to the coil and air gaps for varying the inductance of the ‘ reactor. ‘ 7. A variable reactor for audio frequencies com prising a coil form of insulating material having a central and two end compartments, said corn partments being open-ended, in alignment and disposed in parallel relation, a. coil of wire wound around the coil form in a‘ direction transverse to 10 the direction of the compartments, a pair of lami nated iron cores disposed in parallel planes, each provided with a central limb located in one of the end compartments, each of said cores consti~ tuting a closed magnetic circuit except for an air gap in each core, and an‘ adjustable powdered iron core movable within the central compart ment relatively to the coil and air gaps for vary ing the inductance of the reactor. MORRIS SANDER.