US2678415A - Indicating device for use in remote control of electric motors - Google Patents

Description

y ATTORNEYS.

May 11, 1954 A. D. BAYLOR TNOTCATING DEVICE FOR usE 1N REMOTE CONTROL OE ELECTRIC MOTORS Filed Dec. 30. 1950 Patented May 11,1954

UNITED STATES PATENT OFFICE INDICATING DEVICE FOR USE IN REMOTE CONTROL OF ELECTRIC MOTORS Application December 30, 1950, Serial No. 203,723

(Cl. S18- 208) 2 Claims. l

The present invention relates generally to indicating devices of particular utility in the remote control of television receivers and speci'cally to a novel circuit for a dial light which is illumiH nated when a remote control device is in operation. Various -devices for the remote control of television receivers are well known. They solve the problem involved in permitting the tuning of a television receiver when the operator is sitting in an easy chair or otherwise disposed in a location remote from the television receiver. One fundamental remote control device includes a reversible electric motor which automatically turns the rotor of a continuous tuner, such operation being conventionally performed manually in receivers which are not remotely controlled. The reversible motor turns the tuner rotor one -way or the other until the tuning device or selector is adjusted to receive the desired channel. Such a device conventionally includes a reversible motor such as that illustrated in Fig. 2 and a reversing switch such as that designated by the reference numeral li) in Fig. 1. In accordance with the present invention the remote control device is provided with an indicator in the form of a dial lamp which is energized when the motor is running, the light illuminating a dial and the indicia thereon (not shown) so that the operator can observe when to yturn the motor on or oii'. The present invention also provides a novel circuit for energizing this Idial lamp.

The primary object of the present invention is to yprovide a simplified indicating device including a lamp circuit and a lamp for illuminating the rotating dial of a television receiver tuner.

For a better understanding of the invention, reference is made to the following description of the accompanying drawings, in which there is illustrated a preferred embodiment of remote control indicating `device for television receivers.

In the drawings:

Fig. l is a schematic diagram of the indicator lamp circuit in accordance with the invention; and

Fig. 2 is a top plan view of a suitable commercially available reversible shading coil motor which is utilized in tht,` inventive combination.

Referring now specifically to Fig. l of the drawings, a suitable source of alternating current (not shown) generally la 110 volt household supply, is connected to terminals Il and l2 across which is disposed the main field coil I3 of the motor, the motor being designated by the reference numeral I4 in Fig. 2. This motor includes a set of counter-clockwise wound, serially arranged shading coils l5 and lli connected between contact il and terminal '18, and a set of serially arranged, clockwise wound shading coils I9 and 2!) connected between contact 2l and terminal I8. It is well known to those skilled in the art that set l5 and I6 is conventionally short-circuited to cause rotation of the motor rotor `22 in one direction, and set I9. 20 is shortcircuited to start the rmotor rotor in the other direction.. The terminal I8 is conventionally connected to point X, and the circuit elements to the right of the dashed line Y in Fig. 1 are not conventionally provided. Those circuit elements to the right of line Y are a part of the inventive combination presently describe-d.V A selector switch iii of the single-pole double-throw type or equivalent is included in the controlling equipment disposed at the remote location of the operator. A movable -conductive arm of switch It] is, in accordance with the invention, connected in series circuit with secondary 24 of a transformer 25 and the dial lamp 2B. the latter being shunted by a resistor 2l. A 6.3 volt, 0.15

ampere dial lamp has been found satisfactory. The transformer 25 includes a secondary 24 land a primary 23, the primary being connected across the input terminals yil and l2. A 6.3 volt secondary 24 has been found to be satisfactory, the required voltage rating being the same as that of the lamp.

In conventional circuitry the terminal I8 is connecte-:l to point X and the elements 26, 21, and 24 are not provided. The switch I0 is operated to short-circuit either Set of shading coils, causing the motor rotor to turn in either direction, as is well known to those skilled in the art. The present invention provides a very simple means for energizing the indicator lamp 26 when the `motor M is running. The advantageous indication and illumination of the dial are obtained without the introduction of any vcomplexity into the reversing circuits for the motor lli. The dial lamp 26 is suitably shunted with a parallel resistor 2l so that excessive current does not ow through the lamp when the normal shading coil current flows. The parallel combination of lamp 2B and resistor 2l is placed in series with the common terminal i8 of the two sets of shading coils. If it be imagined that the points Z-Z illustrated in Fig. 1 are connected together, the closing o1" a switch lil would cause the dial lamp to glow, but lthe added resistances in series with the shading coils would reduce the sh-ading coil current to such an extent vthat the motor I4 would not be `allowed t develop' its full torque. On the other hand, the provision of an auxiliary voltage source 24, in series -with both the dia-1 lamp and the shading coils, in the proper phase, brings the shading coil current back to the proper level, point I8 then in effect being 'at a Zero difference of potential with respect to point X, so that the motor develops its starting torque and the dial la'rnp glows with normal brightness.

Referring again to Fig. 2, as stated above the shading coil motor therein indicated vis of a readily available commercial type, It comprises a U-shaped metallic frame 29. A rotor 22 is journaled in suitable bearings for rotation as shown. Wound centrally on the frame is a main eld coil I3. The motor is additionally provided with two sets of shading coils I5, I6 and I9, 20 `as above described.

The construction and operation of shading coil motors per se vare well understood in the art and are discussed in such publications as Lawrence, Principles of AlternateCur-rent Machinery, McGraw-Hill Book Co., Inc., New York, 1940, page 609. The construction of television receiver cabinets and `the location of tuner control dials and 1dial lamps are well understood to those skilled in the art, so that these elements are not shown in detail in the drawings.

While there has Ybeen shown and described what is at present considered to be the preferred embodiment of the invention, it will be understood that various equivalents may be substituted therein without departing from the scope ofthe invention as defined by the appended claims.

I claim:

1. In a television receiver remote control device of the type which includes a reversible shading coil motor having two independent pairs of shading coil windings in two branch circuits and a terminal common to said circuits, a novel indicating device comprising a load including a dial l-amp in series with said terminal, an auxiliary voltage source in 4series with said load, and singlepole double-throw switching means for selectively serially encircuiting said lamp and voltage source with either of said sets of coils and at the same time closing the circuit of that set only.

2. In a television receiver remote control device of the type which includes a reversible singlephase induction type shading coil motor having a 'eld coil and two independent shading coil circuits and a terminal common to said circuits, a novel indicating device comprising a dial lamp in series with said terminal, a transformer having a primary in parallel with said field coil and a secondary providing an auxiliary voltage source in series with said dial lamp, and single-pole double-throw switching means for selectively serially encircuiting said lamp and voltage source with either of said sets of coils and at the same time closing the circuit of that set only.

References Cited in the file of this patent UNITED STATES .PATENTS Number Name Date 2,007,240 Crosthwait July 9, l1935 2,039,155 Ewen i- Apr.` `28, 1936 2,054,680 Naul Dec. l5, 1936 2,253,524 Lilia Aug. 26, 1941 2,256,760 Johnson Sept. 23, 1941 2,275,878 Allenby Mar. 1'0, 1942

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