US2229729A - Power supply system - Google Patents

Description

Jan. 28, 1941. M E

rowrm SUPPLY SYSTEM Filed Feb. 12, 1940 2 Sheets-Sheet 1 Jan. 28, 1941. K. EMDE POWER SUPPLY SYSTEM Filed Feb. 12, 1940 2 Sheets-Sheet 2 INVENTOR. Jill/'25 .ErndQ v IV I, @ia

I I I I I r I UNITED STATES PATENT. OFFICE POWER SUPPLY SYSTEM,

Kurt Emde, Chicago, 111., assignor to Zenith Radio Corpogation, Chicago, 111., a corporation of Illino Application February 12, 1640, Serial No. 318,422

Claims. (01. 171-97) This invention relates tola power supply syscircuit controlling switch, but without the plug; tem for a device operable by electric currents difand fering in character and/or voltage, and more par- Figure 5 is an inverted bottom plan view of the ticularly concerns a novel circuit controlling arswitch and plug of Fig. 3, taken upon the line 5 rangement through which such a device may be and viewed in the direction'of the arrows 55 of 5 selectively connected with one or another of a Fi 4. plurality of sources of electric current supply. As is well known to those familiar with the The principal object of the invention is to pro-- radio art, certain types of radio receiving sets are vide an arrangement 01' the aforesaid character designed for operation by electric current sup- 1 which is operable in a novel manner to not only plied either by power service lines or by battery. effect connection of the device with a selected The type of current supplied by the power service one or another of a plurality of sources of eleclines may be either A. C. or D. C., and the voltage tric current supply, but to prevent connection of may be much higher than that of the battery, the device with more than one of such sources and the battery current supply may be either at a time, and to eflect the connection of the from storage or secondary batteries or from dry- 15 proper power supply circuit of the device with cell or primary batteries. Regardless of the type the selected source of electric current supply. or voltage of the current available from the pow- Another object of the invention is to have the er service lines, and whether storage or dry-cell novel manner of operating the arrangement so batteries be employed, it is'important that, in

simple and so conveniently and obviously presentsuch sets, the battery circuits be disconnected a. ed for use that understanding and caution upon when the power line circuits are connected, and the part of the user is not required, to the end it is customary to equip the sets with a manuthat the power supply circuits oi. the device may ally operable battery switch for this purpose, but not be connected with the wrong source of curthere is no provision against misadjustment of rent and may not be connected with more than the switch. Where a single-throw battery 25 one of said sources at a time. Further explanaswitch is provided and is inadvertently left closed tion of these objects and other objects of the inwhen the power line circuit is connected, the revention will appear in the description to follow. sult will be the draining of the battery, and if a While the invention is primarily designed for double-throw change-over switch is provided for use in connection with the power supply circuits alternately connecting the battery circuit or the 30 of radio receiving apparatus and will be so depower line circuit and it is left in the wrong posiscribed, it will be evident that its usefulness is tion, the battery circuit is unintentionally emnot confined to such apparatus, and I desire not ployed and the battery exhausted, while the user, to be limited thereto, having plugged into the power service line out- In the drawings-- I let-socket, believes power service line current is 35 Figure 1 is a perspective view, illustrating being supplied. It will be evident from the folthe back of a portable radio receiving set, with lowing description that the present invention the demountable rear panel of the outer casing provides against misadjustment of the switch.

removed to disclose the arrangement of the prin- For convenience in illustrating the embodiment 4o cipal elements of the construction hereinafter deoi. my invention in radio receiving pp tus, I scribed as embodying my invention; have shown in Figure 1 of the accompanying Figure 2 is a circuit diagram showing an ardrawings the back of a portable radio receiver rangement, selected for illustrative purposes only, I, the rear outer panel 2 of which has been de- 01 the power supply circuits of radio receiving mounted from the casing and set aside to disapparatus, with which are associated the circuit close the inner panel 3, the storage brackets 4-4 4| controlling switch and power service line plug secured thereto, the power service line cord 4 employed in the herein described embodiment of wound upon said storage brackets, the plug 6 atmy invention; tached to the free end of said cord, the battery Figure 3 is a fragmentary vertical sectional leads I, and the plug receptacle 8. The dry-cell 60 view, upon an enlarged scale,,taken upon the line or primary battery 9 is located at the bottom of 3-3 of Fig. l, transversely through the circuit the receiver, forward of inner panel 3, as indicontrolling switch, showing the power service line cated by dotted lines. If the receiver is to be plug in switch-operating position; operated by electric current supplied by power Figure 4 is a vertical sectional view, taken upon service lines, the cord 5 may be unwound from 68 the line 4-4 of Fig. 3, longitudinally through the the storage brackets 44 and the plug 6 plugged so back of the casing, with the cord extending through a notch (not shown) in the outer panel 2 similar to the notch I I shown in the edge-part,

of inner panel 3. Simple means for holding the panel 2 in position to permit convenient removal and replacement thereof is provided, such as by stepp n a pair of dowel-pins, one of which is shown at l2, into the sockets |3|3 and press ing the catch-member 4 between the spring tongues of the retaining clip l5. Obviously, when the receiver is to be carried about, the plug 6 will be removed from the wall-socket l0, and the cord 5 and plug 6 may be stowed within the space between the outer and inner panels, 2 and 3, respectively. If the receiver is to be operated by electric current supplied by the battery 9, the prongs |6-| 6 of the plug 6 are pushed into the prong-receiving apertures l1-|1 of the plug reoeptacle 8, as indicated in dotted lines in Figure 1 and as shown in Figures 3 and 5. When used in this way, the plug 6 serves as a key for mechanically operating the change-over switch in a manner to be described, but the prongs make no electrical contact and the cord 5 does not connect the receiver with any electric current supply.

Inner panel 3 is removably secured in position within the casing in any desired manner and is apertured at l6 to provide access to the plug receptacle 8 and a passage for the battery leads 1, which are brought out therethrough to the rear of the panel and connected with the battery 9 through an aperture H! by means of the fourpronged terminal plug 20. Battery 9 may be removed and replaced by disconnecting the terminal plug 26 therefrom and removing the inner panel 3.

Referring, now, to Figures 3, 4 and 5 of the drawings, I have shown therein a change-over switch at 2|, the particular interior construction of which will be described, but is not a part of this invention. It is to be understood that any switch construction may be employed which is suitable for the purpose and method of operation hereinafter set forth. Plug receptacle 8 is preferably struck out and formed of stiff sheet metal and, when positioned with the switch thereabove as herein shown, comprises a horizontally extending table-portion 22 .and two downwardly turned vertical flange-portions 23 and 24. Flange-portion 23 is firmly secured preferably to the rear vertical wall of the metal chassis 25, as by screws 26-26, and flange-portion 24 is provided with the prong-receiving apertures |1-|1. Switch 2| is firmly secured upon table-portion 22, as by screws 21-21. Tableportion 22 is bisected by a slot 28, one end-part of which extends a short distance down into the flange-portion 24 and forms the upper one of the two prong-receiving apertures |1-|1 therein. As shown in Figure 5, when the prongs |6-|6 of plug 6 are pushed into the prong-receiving apertures |1-|1, the upper one of said prongs occupies the slot 28, one side of which is cut away to form a recess 29. A tongue is bent from flange-portion 23 to extend horizontally therefrom toward flange-portion 24 just below the lower one of the prong-receiving apertures |'|-|1 and serves as a guide-support beneath the lower. one of the prongs |-6-|6, the upper one of said prongs being similarly guided by the lower surface of the switch-unit 2|, the arrangement being such that, when the prongs |6-|6 are pushed into the respective prong-receiving apertures I'd-I1, they will travel along and be guided between the tongue 30 and the bottom of the switch-unit 2 I.

Switch-unit 2| comprises a fixed contact-supporting plate 3| and a movable member 32, both being formed of insulating material, such as fibre or vulcanite, and encased within a two-part metal shield having a base-member 33 and a cap 34. Base-member 33 has a flat bottom-portion and two upwardly turned side flanges 3636. The opposite end-parts of bottom-portion 35 are provided with threaded openings for the attaching screws 21-21, and the upper edges of side flanges 3636 are formed with tongue-clips 31-31. Movable member 32 slides upon the bottom-portion 35 between side flanges 3636 and is formed with a downwardly projecting lug 38 which extends through an opening 39 in bottomportion 35 and through the slot 28 and recess 29 in the table-portion 22 of plug-receptacle 8. An end wall plate 40 is secured to the side flanges 3636 to close one end of the trough formed thereby, and a coiled compression spring 4| is positioned between the plate 40 and the adjacent end of the movable member 32, the action of the spring being such that, when the prongs |6-|6 of plug 6 are removed from the respective prong-receiving apertures |1-|-1, it will hold the movable member 32 in the position illustrated in Figure 4, wherein the lug 36 engages the right-hand end of the opening 39 and is partly across slot 28 and partly within recess 29. As viewed in Figures 3 and 5, the right-hand and rear vertical surfaces of the lug 38 are beveled or backed away, as at 42, so that, when the upper one of the prongs |6-|6 is pushed into the slot 29, the rounded end thereof will engage with the beveled surface 42 of the lug and force it to one side out of the slot 28' and fully into the recessof the plate and are bent inwardly over the top thereof, as shown at 43. Two sets of three contacts each, 44 to 46 and 41 to 49, respectively, are arranged in line in plate 3|, the contacts being formed and secured in position in the manner illustrated in Figure 3, each contact having an upwardly extending arm 50 to which one of the circuit leads, to be later described in connection with Figure 2, is soldered or otherwise connected. The contact arms 50 and the ends of the leads connected thereto are enclosed by the metal shield cap 34, which is lined with insulating material 5| and provided at the top with an opening 52 for the passage of the leads therethrough. Cap 34 removably fits down over and :grrounds the upstanding parts of base-member Directly below the line of contacts 44 to 49, the upper face of movable member 32 is channeled longitudinally, leaving the upstanding side flanges 53-53 for guiding engagement with the under face of plate SI, and a pair of cylindricalr pockets l4 54 are formed in the body of the member, opening upwardly into the bottom of the channel. Each of said pockets 5H4 houses a 5 coiled compression spring II which surrounds the central stem and acts upwardly beneath the flat circular head of one of two bridging contacts "41. The diameter of the flat circular head of each of the two contacts "-51 is suiiicient to bridge two of the contacts 44 to 48, against which it is held by the action of its spring 5!. As shown in Figure 4, when the movable member 32 is in its rightward position; contact I will bridge contacts 45 and 46 and contact I! will bridge contacts is and 49, while, as indicated by dotted lines in Figure 2, when the member 32 is in its leftward position, contact 5' will bridge contacts 44 and 45 and contact 51 will bridge contacts 41 and 48. It is to be understood that the successful employment of my invention is not in any sense dependent upon the particular arrangement shown in Figure 2. The circuits therein diagrammed are intended to illustrate a practicable manner of connecting the several battery leads I and the power service line leads 58-49 of the cord 5 with the change-over switch 2|, and the employment of the switch to effect the proper adjustment of the power supply circuits of the device in accordance with the character and/or voltage of the electric current supplied through connection of the device with the battery or with power service lines. I have already mentioned that a single-throw battery switch may be employed, if desired, and the circuit connections therewith would differ somewhat from those of Figure 2, but I prefer the double-throw change-over switch herein shown and described to insure the disconnection of the power service line supply when the battery is connected, thereby avoiding the possibility of employing a separate plug to operate the switch and effect the connection of the battery while the power service line is connected and thereby frustrate one of the principal objects of my invention, namely, to prevent connection of the device with more than one source of electric current supply at the same time.

Since this invention is not necessarily concerned with the circuits of the radio receiving set, they have not been illustrated, but it may be explained that the B-plus lead 80 extends to the plate circuit of the first audio frequency tube, B-plus lead 6| extends to the plate circuits of the other tubes, and A-plus lead 62 is connected with the filament or cathode-heating circuit, and,

as is customary, these circuits are finally completed through a common ground return.

Still referring to Figure 2, wherein movable member 32 of switch 2| is indicated in full lines 3 in its rightward position, it may be seen that, upon inserting plug 8 in a power service line socket, as indicated at ill in Figure 1, and closing the on-off switch 4, power service line current will be supplied to the device as follows: 5 lead 58 to rectifier 65, thence through lead 88 to A-plus lead 62 and ground, and through lead 61, contacts 49, 51 and 48, and lead 88 to B-plus lead ii and ground, also through branch-lead 69 and switch 64 to B-plus lead and ground, the sev- 70 eral circuits being completed through ground 63, switch 64, lead III, contacts 45, ii and II, and lead II to lead 59. When movable member 32 is in its leftward position, as indicated by dotted lines, the power service line will be disconnected, since contacts 46 and 49 will not be engaged by the respective bridging contacts 58 and 51, and battery current will be supplied to the device as follows: A-plus lead 12 directly to A-pluslead O2 and ground and back through ground 83, switch 64, lead 10, contacts 45, 56 and 44, to A- 5 minus lead 13; also 'B-plus lead 14, through contacts 41, 51 and 48, and lead 68, to B-plus lead ii and ground, and through branch-lead 89 and switch 84 to B-plus lead 60 and ground, returning through ground 63 and B-minus lead I5. 10

I claim:

1. A power supply system for radio receiving apparatus operable by electric current of one character when connected with one source of current supply and operable by electric current of a 15 different character when connected with a different source of current supply, said system comprising a circuit connecting plug having a contact prong for connecting said apparatus electrically with said one source of current supply, a 20 mechanically operable switch controlling the connection of said apparatus with said different source of current supply, and a plug receptacle having a prong-receiving aperture to receive the contact prong of said plug, said aperture being so arranged with respect to said switch as to permit the insertion of the contact prong of said plug into said aperture to mechanically operate said switch and thereby effect the connection of said apparatus with said different source of current supply.

2. A power supply system for radio receiving apparatus operable by electric current of one character when connected with one source of current supply and operable by electric current of a different character when connected with a different source of current supply, said system comprising a circuit connecting plug having a pair of contact prongs for connecting said apparatus electrically with said one source of current supply, a circuit switch having a movable member controlling the connection of said apparatus with said different source of current supply, and a plug receptacle having a pair of prong receiving apertures to receive the contact prongs of said plug, one of said apertures being so arranged with respect to said switch as to permit the insertion therein of the respective one of the prongs of said plug to engage with and operate the movable member of said switch and thereby effect the connection of said apparatus with said different source of current supply.

3. A power supply system for radio receiving apparatus operable by electric current of one 55 character when connected with a first source of current supply and operable by electric current of a different character when connected with a second source of current supply, said system comprising first and second circuit connections for 60 connecting the apparatus with said first and second sources of current supply, respectively, a circuit connecting plug in said first circuit connection having a contact prong for connecting said apparatus electrically with said first source 65 of current supply, a mechanically operable change-over switch acting upon adjustment thereof to open either one and close the other of said circuit connections, and a plug receptacle having a prong receiving aperture to receive the 70 contact prong of said plug, said aperture being so located with respect to said switch as to permit the insertion and withdrawal of the prong of said plug into and from said aperture to control the adjustment of said switch and thereby determine 7 which of said circuit connections shall be opened or closed.

4. A power supply system for radio receiving apparatus operable by electric current 01' one character when connected with a first source or current supply and operable by electric current of a diiferent character when connected with a second source of current supply. said system comprising first and second circuit connections for connecting the apparatus with said first and sec- .ond sources of current supply, respectively, a circated with respect to said switch as to permit the insertion of the prong or said plug into said aperture to eflfect the adjustment of said switch to open said first and close the second of said circuit connections. I

5. A power supply system for radio receiving apparatus operable by electric current of one character when connected with a first source of current supply and operable by electric current or a difierent character when connected with a second source oi. current supply, said system comprising first and second circuit connections for 5 connecting the apparatus with said first and second sources 01 current supply, respectively, a circuit connecting plug in said first circuit connection having a contact prong for connecting said apparatus electrically with said first source 01' 10 current supply, a circuit change-over switch having'a movable member operablein one direction to close the first and open the second of said circuit connections and operable in the other direction to cpen the first and close the second of 15 said circuit connections, means acting upon said movable member to operate it in said one direction, and a plug receptable having a prong receiving aperture to receive the contact prong of said plug, said aperture being so located with re 2t spect'to said switch as to permit the insertion of the prongof said plug into said aperture to act upon said movable member to operate it in said other direction against the influence of said means. 25

KURT EMDE.

Images