- 12, 1946. ' L. HILLMAN 2,410,821 SELECTIVE mbrcnine SYSTEI Filed Aug. 2a, 1943 INVHVTOR. LEN MLMAN Patented Nov. 12, 1946' 2,410,821‘ ‘UNITED STATES PATENT OFFICE ' ' - 2,410,821 ‘ SELECTIVE INDICATING SYSTEM Leon Hlllman, New York, N. Y. , Application August 28, 1943, Serial No. 500,397 7 Claims. (c1. 177-353) ' (Granted under the, act of March 3, 1883, as amended April 30, 1928; 370 ‘0. _G. 757) l z The invention described herein may be manu factured and used by or for the Government for governmental purposes, without the payment to electrically connected to the other line 31 of the two line cable by means of any convenient sliding me of any royalty thereon. tion determined by the direction of the wind, it . contact. When the vane turns to assume a posi , This invention relates to telemetering systems and more particularly to systems for transmitting and indicating intelligence, such as might be ob tained from meteorological observations. Heretofore, in order to transmit the results of causes a similar rotation of the contactor arm 38 which, by its connection to the line 31, completes the circuit through the particular segment with which‘ it may be making wiping contact, and thence through the associated one of the resistors continuously changing meteorological observa 10 20-34. _ ’ ' ‘A conventional power supply is conveniently tions it has been necessary to provide a plurality of transmission lines, each of which was used to located at the receiver and, as shown in the ?g ure, it comprises a recti?er 40 whose input is a carry a signal corresponding to an instantaneous 60 cycle 110 volt supply, and-whose output is fed value of a particular ‘observation. In such a sys tem, an increase in the number of desired obser 15 through a bleeder potentiometer ‘calibrating con trol 42 to a parallel bank'of differentially oper vations obviously, causes an increase in the num ated electro-magnetic relays 44—58. Meter M is provided in order to aid in the calibration of the relays to predetermined current sensitivities. In resulting from the grouping of the individual lines becomes heavy and expensive with regard to 20 order to make these relays di?erentially respon sive to currents of varying magnitudes they may the actual material required. be formed of coils ‘having graded numbers of An object, therefore, of this invention is to pro turns, or, they may be provided with armatures vide a system for transmitting and indicating Gil-14 of graded weights, or, the holdback information of this type wherein a two-wire transmission line is employed regardless of the 25 springs (not shown) of eachv of the armatures may be maintained at varied tensions, or, any number of independent observations to be made. combination of the foregoing expedients may' be To the accomplishment of the foregoing gen used for the same‘ purpose. serially connected eral object, and such other more speci?c objects with said armatures is a bank of small electric as hereinafter appear, my invention consists in ' the apparatus elements and their relations to one 30 light indicator bulbs ‘Ht-90.- Thepower source for the bulbs may be the above-mentioned 60 another as are hereinafter described and sought cyclellO voltsupply across which is connected 2. to be claimed in the following speci?cation. The step-down transformer 92. The secondary of the speci?cation is accompanied by a drawing in step-down transformer contains, in its output cir which the single ?gure is a schematic wiring dia 35 cuit, the relay contacts arranged in two rows gram of my invention. I with each row having eight contacts, the row 96 Referring to the drawing wherein there is dis containing the “break”'wcontacts, with which closed a transmitter A and a receiver B connected armatures 60-14 are normally in engagement, thereto by means of a two-wire cable, the trans and the row 94 containing the “make” contacts mitter comprises a commutator 2 which is of the split ring type including a plurality of ?xed insu 40 with which said armatures are pulled into en gagement upon energization of coils 44-58. lated segments 4-48. While the illustrated de Let it be assumed that the wind vane is directed vice shows eight such segments it will be under so that the arm 38 makes contact with segment 4, stood that the invention is not limited to this ber .of transmission lines required to carry the intelligence with the result that often, the cable 1 number, - - ' Electrical connection from each of the seg as shown in the ?gure by the dotted line. When this is the case, resistor 20 is introduced into the ments 4-—I8 to the two-wire cable is made circuit, and, assuming that said resistor is the through graded resistors 20-34, one each 01’ the lowest value resistor of the bank, the current in resistors being connected at one terminal to one the two-wire cable is a maximum. Suitable ad justment of the calibrating control 42 may be each of the segments 4-—l8, while the other resis tor terminals are connected in parallel and to one , wire 36 of the two-wire cable. Rotatably mounted at the center of the commutator 2 is a contac tor arm 38 which is connected to a rotatable standard bearing a meteorological element as for example a wind vane (not shown). made in order that, under such conditions all the relays 44--58 are energized sufficiently to throw all the armatures 60—'l4 from their “break” posi tion, as shown, into engagement with‘ their “make” contacts in row 94. It will be obvious Arm 38 is 65 that, with all armatures in this position, current 2,410,821 3 4 position while the other contact is in its ?rst posi will flow from terminal 96 of transformer 92, tion to remove the short circuit from only one of through lamp 90 and armature 14, to the termi said elements and to connect it across said source nal 94 of said transformer, only the lamp 50 of current to cause operation of only said one ele passes enough current to cause it to glow, the and means responsive to positioning of other lamps ‘I6-—88 being effectively shorted out 5 ment, both contacts in the second position to remove by the armature ‘H. ' the short circuit from only the other element and When the direction of the wind shifts enough to cause the contactor arm 38 to wipe across seg to connect it across said source to cause operation of only said otherelement. ment 6, resistor 22 replaces resistor 20 in the cir 3. A selectively-operable electrical signal sys cuit and, provided that the former resistor is 10 tem comprising at least a pair of identical signal somewhat greater in value than the latter resis elements, a source of current normally discon tor, the current value in the circuit is reduced proportionately. nected from said elements, at least a pair of re motely controlled electromagnetic relay switches As a result, we ?nd all the armatures 60-42 are drawn into “make” position, except armature 16 each having ?rst and second positions. means in 14 which, assuming that its relay coil 58 is in sensitive to the current value now maintained, remains in “break” position. When this situa tion obtains, it will be clear that current will ?ow cluding said switches when both are in their ?rst ‘ positions to short circuit each of said elements, means responsive to positioning of one of said switches to its second position while the other is in its ?rst position to remove the short from terminal 96, armature ‘I4, lamp 88v and 20 switch circuit from only one of said elements and to con armature 12, now in the “make” position,- to the nect it across said source of current to cause terminal 94, so that only the lamp 88 passes cur operation of only said one element, and means rent enough to make it light up, because contact responsive to positioning of both switches in the 14 will short out lamp 90, the remainder being second position to remove the short circuit from only the other element and to connect it across said source to cause operation of only said other element. 4. A system as set forth in claim 2, wherein made to glow. Thus, by merely observing the said relays are graded so that they operate in bank of bulbs to see which one happens to be lit, 30 response to different potentials applied thereto. the observer may ascertain the direction of the said relays being connected in parallel to a source wind at the transmitter. of variable potential. effectively shorted out by armature 12. In a sim ilar manner, it may be shown that corresponding to each segment 4-—l 8 with which the arm 38 may come into contact, there is one lamp which is It will be understood that other meteorological 5. A remote-control system comprising a pair fall measuring device, or wind velocity instru 35 of terminals adapted to be connected to a source of current, a network including a plurality of ment, each provided with suitable gear mecha load circuits 'connected in end-to-end relation nism to operatively connect the element to arm ship, one end of said network being connected to 38, may likewise be employed at, the transmitter one of said terminals, means to selectively com with similar results. plete the connection of said load circuits to the 40 Having described the preferred form of my In other of said terminals, said means'comprising a vention, many modi?cations may become appar plurality of relays, each having an armature con ent to those skilled in the art and I wish it to be nected to a diiferent junction between said load understood therefore-that my: invention is limited circuits, each relay having a break-contact and only by the scope of the appended claims. 45 a make-contact cooperating with its armature, I claim as my invention: said break-contacts being all connected to one 1. A selectively-operable electrical system com of said terminals, and said make-contacts being prising at least a pair of identical elements, a connected to the other of said terminals. source of current normally disconnected from 6. A remote-control system comprising a pair said elements, at least a pair of switches each having ?rst and second positions, means includ 50 of terminals adapted to be connected to a source of current, a network including a plurality of ing said switches when both are in their ?rst signal lamps connected in end-to-end relation positions to short circuit each of said elements, ship, one end of said network being connected to ‘ means responsive to positioning of one of said one of said terminals, means operable from a re switches to its second position while the other mote point to selectively complete the connection 55 switch is in its ?rst position to remove the short elements, as for example an anemometer, a rain circuit from only one of said elements and to con nect it across said source of current to cause op eration of only said one element, and means re of said lamps to the other of said terminals, said - means comprising a plurality of electromagnetic relays, each having an armature connected to a different junction between said lamps, each relay sponsive to positioning of both switches in the second position to remove the short circuit from 60 having a break-contact and a make-contact co operating with its armature, ‘said break-contacts only the other element and to connect it across being all connected to said one of said terminals, said source to cause operation of only said other element. 2. A selectively-operable electrical signal sys tem comprising at least a pair of identical signalw elements, a source of current normally/"discon nected from said elements, at least/a’ pair of re lays each including contacts having first and sec ond positions, means including said contacts when both are in their ?rst positions to short cir 70 cuit each of said elements, means responsive to positioning of one of said contacts to its second and said/,mak’e-contacts being connected to the other'o'f?said terminals. 'I. A system as set forth in claim 6, wherein said relays are graded so that they operate in re sponse to different current strengths through their coils, means connecting all said coils in parallel with a source of current, and means at said remote point to vary said current. LEON HILLMAN.