US2013201A - Combined reproducing and recording device - Google Patents

Description

Sept. 3, 1935. R, DALLY 2,013,2U1

COMBINED REPRODUCING AND RECORDING DEVICE Original Filed Oct. 29, 1951 REPAODucE' 3 w 3 zwm- Patented Sept. 3, 1935 COMBINED REPRODUCING AND naooanme DEVICE Roy Dally; Racine, Wis., assignor to Webster Electric Company, Racine, Wis., a corporation the reproduction and recording of sound of Wisconsin Original application October 29,1931, Serial No. 571,727, now Patent No. 1,902,950, March 28,

1933, Serial No. 659,644

Divided and thisapplication March 6,

4 Claims. (01. 119-10041);

The present invention relates to, combined reproducing and recording devices of the type ,commonly called ,pick-ups, and is particularly ,uconcernedv ri'th the provision of an improved pick-up which is adapted to be used for both on ex isting radio receivers. I

The present applicationis a division of my prior application, Serial .No. 571,727, filed October 29, 1931, now Patent No. 1,902,950, granted March 28, I933, on Combined reproducing and record ing devices, which parent applicationrelates to the complete apparatus used in recordingand reproducing. The present application includes claims on subject-matter held divisible fromv the claims ofthe parent application, and relates to the pick-up unit per se.

lliodern radio receivers usually have an audio frequency amplifierwhich is .suitable for record I Q6" reproducing or recording when properly. coupled "to the necessary apparatus. For reproduction, a pick-up of a fairly highimpedance is required, such as, for example, a pick-up having about five thousand of wire, and the pickcoupled directly to the grid circuit of the detector tube, or if the audio amplifier includes 'more than one stage it may be connected to the tube following the detector, or it may be coupledto the primary of one of the audio transformers used in the radio receiver.

For the purpose of the present description, e'i'ther'one of these modes of connection may be considered as-a connection to the input, side of "the amplifier" or to the input side of a per- So long as the pick-up has a fairly high impedanceit is not necessary to add any additional equipment to the amplifier in order to reproduce records, other than the pick-up itself. 'If, on

{the other hand, a pick-up of low impedance is used, in order'toi secure satisfactory results, it

is necessary to couple the pick-up to the amplifier through a high ratio transformer. This involves additional expense and usually results in a low efficiency, and it is therefore desirable to use for reproduction purposes apick-uphav ing a highimpedance, coupled directly to the "grid circuit of oneof the audio amplifier tubes.

For the purpose of recording or cutting records, the same high impedance 'pic'k-upmay be used "with fair results when coupled to the amplifier output tube or tubes, through the proper type of transformer. Here again a special transformer isrequired if it is desired to utilize the same high impedance pick-up reproducing. V

Since modern receivers are designed to operate a dynamic speaker, having a very low voice coil impedance, it would be possible to use the voice coil winding of the output transformer only if the pick-up Winding has a verylow impedance comparable with the speaker voice coil.

When the pick-up is used as a cutter, it is esfor both recording and ,sentially a powerdriven device and quite sirnilar to the speaker itself in this respect, and a more ideal and efiic'ient arrangement would be attained if the cutterimpedance were relatively low, or as low in value as that of the speaker voice coil; A cutter impedance coil of such a low value could be coupled to the output transformer secondary, replacing the speaker and recording could 'be accomplished under more. nearly ideal conditions without the necessity for additional equipment. For example, the impedance of the low'impedance winding with the circuit of the high impedance coil open, was made about twelve and a half ohms with a certain speaker.

It will thus be observed that the ideal -re-, quirements for a simple reproducer. are inconsistent with the ideal requirements for a simple recorder in so far as the impedance is concerned and the ordinary reproducers and recorders cannot be utilized interchangeably without the liecessity for'additional equipment which increases the expense and decreases the efiiciency of the device.

One of the objects of the present invention is the provision of an improved pick-up which is also adapted to beutilized for recording without the necessity'for' providing additional equipment to adapt the. device for either of its functions.

Anotherobject is the provision of an improved recording device which is also adapted to be utilized for reproduction without the necessity for providing additional equipment, such as transformers or the like.

Another objectis the provision of an improved combined reproducing and recording device, which is adapted to be used with modern radio receivers without the necessity for providing special equipment tof adapt the radio receiver to the use of the reproducer or recording device. Another object is the provision of an improved reprcducing and recording device which'is-more eflici'ent than the devices of the prior art, in

which the same pick-up maybe utilized for either reproduction or-recording by merely switching different parts of the pick-up into circuit.

' Other objects and advantages of the invention will be apparent from the following description, and from the accompanying drawing, in which similar characters of reference indicate similar parts throughout the several views.

Referring to the single sheet of drawing:

Fig. l is a diagrammatic view of the apparatus and circuits required for one embodiment of my invention;

Fig. 2 is a similar diagrammatic view of the apparatus and circuits for another embodiment of the invention;

Fig. 3 is a fragmentary View in partial section of a combined pick-up and reproducer of the type which may be used in either Fig. 1 or Fig. 2.

Referring to Figs. 1 and 2, the present apparatus preferably includes the combined reproducer and recorder I0, and amplifier I aswitching arrangement l2, a microphone I3, and a speaker l4. Any type of suitable amplifier, speaker or microphone may be utilized, and therefore these elements are merely shown diagrammatically.

The pick-up is preferably of the type shown in Fig. 3, provided with a supporting casing 5|, a permanent magnet 52 having pole pieces 53, a stylus 54, and coils 55. The stylus 54 is movably mounted, being carried by the armature 56, which is preferably supported upon knife edges and all of the details of the present pick-up, except the coils, may be made substantially the same as that disclosed in the application of William H. Hutter, Serial No. 488,243, filed October 13, 1930 now Patent No. 1,934,857, granted Nov. 14, 1933.

The present pick-up is distinguished by the provision of separate windings or separate taps for a common winding, for providing windings having a proper impedance for both the functions recording and reproducing most efliciently, and without the necessity for additional apparatus.

Thus, in Fig. 1, the winding |5 which is represented as a longer winding, is a winding of high impedance adapted to be used without the necessity for transformers when directly connected to the input side of the amplifier ID. The high impedance winding I5 is preferably connected bya conductor Hi to a fixed contact while the other side of the high impedance winding I5 is connected by a conductor I8 to a fixed contact l9.

The pick-up also includes a low impedance winding 20 having an impedance comparable to the impedance of the voice coil of the speaker l4, and one terminal of the low impedance coil 20 is connected by conductor 2| to a. fixed contact 22. The other terminal of the low impedance coil 20 is connected by conductor 23 to fixed contact 24. The microphone I3 has its terminals connected by conductors 25, 2 6 to fixed contacts 21, 28, respectively. The speaker M has its terminals connected by conductors 29, 30 to fixed contacts 3|, 32, respectively.

The input side of the amplifier l has'its terminals connected by conductors 33, 34 to the movable contact arms 35, 36, respectively. The output terminals of the amplifier II are connected by conductors 31, '38 to the movable contact arms 39, 48, respectively. All of the contact arms 35, 36, 39 and 4B are preferablyjoined by an insulating member 4| so that they may be simultaneously actuated by the same actuating member 42.

The switch is also preferably of the snap type, adapted to move quickly from one position to the other, and adapted to be positively secured in either of its positions. For this purpose, the insulating member 4| has been illustrated with a pair of grooves 43, 44 adapted to be engaged by a spring pressed ball 45. The switch is also preferably provided with arrows 46 and appropriate indicia for indicating the functions of the device in the different switch positions, such as Reproduce and Record. When the switch I2 is in the position of Fig. 1, it has been moved to the recording position, and when the switch is moved to the left in Fig. 1, it is moved into the reproducing position.

Refcrring to Fig. 2, this is another modification in which the reproducer is provided with a single coil 4! having a plurality of taps. The end taps l6 and 23 may be considered the same as the conductors previously described in connection with the device of Fig. 1. The center tap 48 performs the functions of both the conductors I8 and 2| of Fig. 1. The tap 4B is connected to windings 41 in such manner that the upper winding 49 is the high impedance winding for reproduction, while the lower winding 50 is the low impedance winding for recording.

The operation of the present recording and reproducing device is as follows: When the switch I2 is in the position of Fig. 1, or that of Fig. 2, the low impedance winding 20 or 50 is connected in circuit with the microphone l3, and the circuit may be traced from the microphone to the amplifier as follows: I3, 25, 21, 36, 34, 33, 35, 28, 26, IS. The circuit may be traced from the amplifier to the recorder as follows: 38, 40, 24, 23, 2|), 2|, 22, 39, 31,

The microphone I3 is thus connected to the amplifier and the low impedance coil 20 is connected to the output side of the amplifier in such manner as most efiiciently to effect the recording of sound without the necessity for using intermediate transformers or other devices which reduce the efficiency. The low impedance coil 20 is thus substituted for the voice coil of the speaker |4. V

When the switch I2 is moved to the left in Fig. 1 or Fig. 2 the microphone and low im-' pedance coil are cutout and the speaker l4 and high impedance coil I are cut into the circuit. Under these conditions, the circuit may be traced from the high impedance coil I5 to the amplifier, as follows: |5, |8, Hi, 36, 34, 33, 35, l1, l6, IS. The circuit may be traced from the amplifier to the speaker M as follows: 31, 39, 3|, 29, I4, 30, 32, 40, 38, The speaker is thus connected in circuit .with the amplifier and the high impedance coil of the pick-up is substituted for the low impedance ,coil for the purpose of reproduction.

It will thus be observed that the present device may be used for reproductionand for re-, cording without the necessity for using intermediate transformers, and the present pick-up may be ideally adapted for both reproduction and recording. Thepick-up may thus be attached to existing radio receivers with a minimum amount of expense and labor, and the present device is more adaptable and conveniently applied than the devices of the prior art.

Having thus described my invention, what I claim is new and desire to secure by Letters Patent of the United States, is:

1. A combined reproducing and recording device, comprising a permanent magnet, a stylus and an armature movably' supported with respect to said magnet, a-low impedancecoil adapted -to be utilized for recording, and a high impedance coil adapted to be utilized duction.

2. A combined reproducing and recording device, comprising a permanent magnet, a stylus and an armature movably supported with respect to said magnet, a coil having a low impedance for reprosection for recording and having a high impedance section for reproduction, and taps connecting with said low impedance and high impedance sections for selective use of the sections of said windings.

3. A combined reproducer and recorder comprising a permanent magnet, a stylus and an armature movably supported with respect to said for recording, said low impedance coil having its electrical characteristics suitable for substitution for a speaker, and a high impedance coil adapted to be utilized for the reproduction.

4. A combined reproducing and recording device comprising a permanent magnet, a-stylus and an armature movably-supported with respect to said magnet, a low' impedance coil adapted to be utilized for recording, and a high impedance coil adapted to be utilized for reproduction, said high impedance coil having suitable electrical characteristics whereby theihigh impedance coil may 'be substituted for the microphone in a reproduction circuit.

ROY DALLY. I 15

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