US1862123A - Remote control system - Google Patents

Description

June 7, 1932. P F, SHUEY 1,862,123

REMOTE CONTROL SYSTEM Filed Oct. 30, 1928 2 Sheets-Sheet 1 IVENTOR PaZzZ F 5/7 uey.

June 7, 1932.

P. \F. SHUEY REMOTE CONTROL SYSTEM Filed Oct. 30, 1928 2 Sheets-Sheet 2 INVENTOR Paul F. Shuy ATTORNEY Patented June 1, 1932 rant. 1. snunrgor SWISSVALE, I rare at manurae'runme PENNSYLVANIA, ASSIGN'OR TO WESTINGHOUSE ELEC- COMPANY, A CORPORATION OF PENNSYLVANIA minors CONTROL SYSTEM Applicationifiled- October 30, 1828. Serial No. 316,039.

' My invention relates to control systems for electrical, devices and, it is one of the principal objects ofiny invention to provide a system whereby of 'any control such devices may be conremote point without the use circuits except that required to furnish energy to the load device. My invention is designed particularly to control street-lighting installations but, obviously,

trolled from a has many other applications.

-' Another object of my invention is the provision of a remote-control system which shall .not be subject to accidental operation by line surges or other abnormal circuit conditions.

further ob ect of. my lnvention is to employ a superposed hig -freqnency control current in combination with a tuned circuit,

including a relay, to effect the control of electrical devices from a remote point.

vA further object of my invention is the provision of a control system whereby it will be possible to effect the connection and disconnection of a plurality of load devices to and from a supply circuit independently,

J function.

using only two control frequencies.

My invention is an improvement upon the system described in the Electric Journal for February 1927, pp. 72-77, and is also an improvementupon the systems coveredby the applications of W. W. Edson, Serial No. 302,983, filed August 30, 1928, and L. J. Gorman, Serial No. 311,540, filed October 10, 1.928.

In the publication hove referred to, a system of controlling street lamps by means of tuned relays and superposed high-frequency current is described.

The Edson application above mentioned is an improvement upon the system described in the article and includes thermal relays, the function of which is to prevent accidental operation of the tuned relays by line surges of the appropriate frequency.

The Gorman application also makes use of a thermal relay to change the controlcircuit connections after a load device has been connected to the supply circuit, so that, after such operation, the tuned relay may be utilized to perform an additional control 'ergization of The systems of my invention disclosed herein, as heretofore stated, are improvements in the specific control circuits employcd in the systems referred to.

One of the particular advantages of my invention is that it may be employed to control load devices having different schedules of operation. It may be desired, for example, to connect all the lamps of a given streetlighting installation in circuit upon the approach of darkness, to disconnect a portion of the lamps at midnight and to disconnect the remaining lamps at daybreak.

Another advantage of my invention is that the combination of tuned relays and thermal relays may be employed toselect any one of a number of different functions that are to be performed.

For a complete understanding of my-invention, reference is made to the accompanyi'ing drawing, in which- Figure l is a circuit diagram of the improved control system of my invention, and

Figs. 2 to 4 inclusive are circuit diagrams illustrating modifications thereof.

Referring to Fig. 1, there is shown a system in which provision is made for independently controlling two separate load devices or lamp banks by means of'only two control frequencies.

The supply circuit may be connected to any suitable source of supply, such as an alternating-current generator (not shown). A pair of lamps 27 and 28, which, instead of being single lamps, as illustrated,-may each consist of a battery of lamps or any other load device, is adapted to be connected to the circuit 10 through the switches and 26. The switch 25 is operated by the electromagnets 25a and 25?) which serve to open and close the switch 25, respectively. The switch 26 is also provided with similar electromagnets 26a and 26b. The switches are so designed and constructed that their armatures remain ineitheiof their two positions until actuated therefrom by the energization of the appropriate electromagnet. 4 The enthe electromagnets 25a, 25b, 26a and 26b is controlled by a plurality of alternating- current relays 15 and 16 which are connected across the supply circuit 10 in series with condensers 17 and 18, which, with the relays, form tuned circuits.

The relays and 16 are adapted to be energized by alternating current of a predetermined frequency to which the tuned circuits are resonant. The high-frequency control current may be superposed upon the circuit 10by any suitable means. The circuit 10, relays 15 and 16 and condensers 17 and 18 of the system in Fig. 1 are common to all the other figures of the drawing.

In addition to the relays 15 and 16, thermal relays 19 and 20 assist in the control of the electro-magnetic switches and 26. The

thermal relays 19 and 20 may be standard lamp flashers, which are well known in the art and consist merely of a bimetallic thermal element and associated heating coil, or they ma be of any other suitable construction. T e contact of the thermal relay is normally open but is closed shortly after the application of voltage to the heating coil.

. The closing of the contact of the relay short circuits the heating coil Which, thereupon,

cools to permit the relay to open the contact. The heating coil is again placed in the circuit, and the alternate closing and opening of the relay contact would be repeated, ex-

cept for the provision of means, which will be explained later, for deenergizing the thermal rela after its first operation.

The function of the thermal elements 19 and 20, in my system, is to prevent the operation of the switches 25 and 26 in case the relays 15 and 16 should be momentarily energized by a voltage of the proper frequency or some abnormal condition on the circuit 10, such as line surges resulting from lightning or switching operations.

An additional thermal switch 29 is provided to change the circuit connection from the closing coils of the switches 25 and 26 to the opening coil of the switch 25.

The system shown in Fig. 1 operates as follows: In response to the superposition of a control current of the proper frequency on the circuit 10, the relay 15 operates to close its switch. This completes a circuit from one side of the circuit 10, through the lamp 27, the switch of relay 15, the upper contact of thermal relay 29, through the closing coils 25b and 26b of the switches 25 and 26 in parallel and the thermal relay 20, to the other side of circuit 10, the upper contact of the thermal relay 29 being normally closed.

The closing of'the switches 25. and 26 connects both lamps 27 and 28 across the supply circuit and energizes the heating coil of thermal relay 29, with the result that the upper contact thereof is opened and the lower contact closed. Now, when it is desired to disconnect the lamp 27 from the circuit 10, it is only necessary to operate relay 15 a second time, upon which the circuit to the opening coil 25a of the switch 25 is closed and the switch itself opened. *The openin of the switch 25 disconnects the lamp 27 roin the circuit 10 and deenergizes the heating coil of the relay 29 which assumes its normal position in which the upper contact is closed. Then, when it'is desired to disconnect lamp 28, the relay 16 is energized bycontrolcurrent of proper frequency to complete a cirwhich differs only slightly from that shown in Fig. 1. The lamps, controlswitches, re-- lays, condensers and thermal elements are indicated in Fig. 2 by the same numerals as in Fig. 1. In the system of Fig. 2, however,

the thermal relay 29 funtionsto transfer the relay 16 from the opening coil of the switch 25 to the opening coil of the, switch 26.

When the control frequency to-which the circuit 1715 is resonant is applied to the circuit 10, relay 15. operates and connects the closing coils of the switches 25 and .26. in parallel across the supply circuit 10 in series with the thermal relay 19. Theclosing of the switches 25 and 26 connects both lam s 27 and 28 to-the same circuit, and, at t e same/time, energizesthe heating coil of 'the relay 29, which, in this instance, normally has its lower co'ntactclosed- When the heating element of this relay is energized by the closing of the switches 25 and 26. however, the upper contact soon closes, so that, when the relay 16 is subsequently energized by the appropriate freqlfency, the opening'coil of the switch 25 will be energized to disconnect the lamp 27 from the supply circuit. The heating element of relay 29 will, likewise, be de-energized, the upper contact opened and the lower contact closed. The next energization of the relay 16 will complete a circuit including the opening coil of the switch 25 to disconnect the lamp. 28 from the circuit 10.

In Fig. 3, I have illustrated a system in which the combination of the tuned relays 15 and 16 with the thermal relays, such as;-1 9 and 20, may be employed to select one f-5a number of operations to be performed. The relays 19 and 20 of F ig. 3 have differing time elements, as indicated by the legends. Relays 35, 36 and 37 are controlled by the thermal elements 19 and 20 to accomplish various operations.

When the control frequency peculiar to the relay 15 is impressed u on the circuit 10, the relay 15 closes its switch to connect the heating elements of all the relays 19, across the supply circuit 10, in series with a resistor 38.

naeams The relays 19 operate successively to close time settings.

their contacts and energize the relays 35, 36 and 37. Each of these relays closes its own locking circuit and any additional control circuit. K

It is obvious that the relay 19, having a time setting of one second, maybe actuated without affecting the relays having longer In this way, it is possible to select which relay is to be operated, but it is also obvious that all relays having a time interval shorter than that of the desired relay will also be operated. V

When it is desired to disconnect any of the devices controlled by the relays 35, 36 and 37, it is only necessary to energize the relay 16 by the appropriate "control frequency, whereupon the thermal relays 20 will be successively operated. The operation of any of the relays 20 completes a short-circuit around the operating coil of the relays 35, 36 and 37 which are thereupon dc-energized, and the consequent opening of their contacts disconnects the various devices controlled thereby from the circuit '10. I i

In Fig. 4, I have illustrated a still-further modification of the control system of my invention. This system is adapted to control a plurality of load devices by means of only two different control frequencies. In the system of Fig. 4,the tuned relays 15 and 16 functions, in the same manner as in the modifications already described, to control electromagnetic switches 38 and 39 which are provided with closing and opening coilsl' These switches control the connection of the devices 27 and 28 to the supply circuit 10.

Thermal relays 40 and 41 of any suitable type having differing time limits, serve to control the connections to the operating and tripping coils of the electromagnetic switches 38 and 39. A third thermal device 20 and also the relay 40 function, as in the other modifications, to prevent operation of the relays 15 and 16 by line surges. V

In order to connectthe devices 27 and 28 to the circuit 10, the relay 15 is energized by a control frequency to which the tuned circuit 15-17 is resonant, and the relay 15 opcrates to close a circuit to the closing coils of the switches 38 and 39. This circuit traverses the load device 27, the switch of the relay 15, the closing coils of the switches 38 and 39, in parallel, and'the. thermal relay 20.

The switches 38 and 39 being closed the dewl'tijces 27 and 28 are connected to the circuit The switch 38 is provided with an auxiliary contact which, in the closed position of the switch, completes a. circuit for the opening coil thereof and which, in the open position, completes a circuit for the opening coil of the switch 39.

When the relay 16 is energized by control current of suitable frequency, its switch is vnecessary to operate the relay closed to complete a circuit from one ,side of the circuit 10, through the switch of relay 16, the thermal device 40, having a comparatively short time delay, the opening coil and auxiliary front contact of the switch 38 and the switch 39, tothe other side ofthe circuit 10. The completion of this circuit effects the opening of the switch 38, and the de-energizat-ion of the opening coil thereof. f

\Vhen it is desired to disconnect the load device 28 -from its-supply circuit 10, it-is only 16 again by suitable control frequency. This operation completes a circuit from one side of the supply source 10, through the switch of the relay l6, thermal lay. the opening coil of the switch-39, the auxiliary back contact of the switch 38 and the. switch 39, to the otherside of the circuit 10. Thus, the switch 39 is opened, and

the circuit to the opening coil thereof s inmay be obtained by means of only 'two control frequencies. p I

I have illustrated several modifications of systems of my invention but do not intend to be limited to the specific trated and described herein, since obvious changes may be made without departing from the spirit and scope of my invention as defined in the appended claims.

I claim as my invention:

1. A system for controlling thebonnection of a plurality ofelectrical devices to a main energy source from a remote point comprising tuned circuits connected across said main source, relays in said tuned circuits responsive onlyto alternating current of a predetermined frequency, and electromagnetic switches controlled by said relays for controlling the connection of said electrical devices to said main source, said electromagnetic switches having closing and opening coils, thermal relays connected in series with said closing and opening'coils and a thermal switch controlled by the energization of one of said devices for setting upa circuit the completion of which effects the disconnection of another of said devices. a

2. The combination with a plurality of electrical devices adapted tobe connected to a main circuit of .a plurality of tuned cir-' euits, relays in said circuits, and a plurality of thermal relays of differing time elements adapted to he simultancouly energized under the control of said relays, and means responsive to the operation of said thermal relays gu'ibodiments illus device 41 having a long time deof electrical devices comprising tuned relays, electromagnetic switches for said devices and a changeover switch actuated by the closing of said switches for setting up a circuit toopen one of said switches in responseto the next. operation of one of said relays.

4. In a remote-control system, the combination with two tuned,relays,'of a plurality of electromagnetic switches for independent- 1y controlling the connectioifof electrical devices to a supply circuit, one of said relays serving to effect the closing of said switches. a thermal relay energized by the closing of said. switches for changing circuit connections, whereby the operation of the other tuned relay effects the disconnection of oneof said devices and deenergizes said thermal relay so that the next operation of the secondrelay causes the disconnection of another of i said devices.

5. The combination, in a control system, with a plurality of relays, switches controlled by said relays for connecting electrical devices to a supply circuit, of a thermahSWitch actuated by the closing operation of said switches in response to the operation of one of said relays, for setting up a circuit 0011- trolled by said relay for opening one of said switches 'when said relay is next operated, the opening of another of said switches being controlled by another of said relays.

6. In a control system, relays "responsive only! to alternating current of a predetermined frequency, switches controlled by said relays for connecting electrical devices to a supply circuit, and means rendered operative in response to the closing operation of one of said switches under the control of one of said relays for rendering the other relay effective when again operated to open said switch.

7. In a control system, a plurality of relays responsive only to alternating current of a predetermined frequency, switches controlled by. said relays for connecting electrical devices to a supply circuit, and means opera tive after the closing of said switches in response to the operation of one of said relays cuit, and means rendered effective inres onse to the operation of one control switch e ected by the operation of one tuned relay for rendering the other tuned relay effective when operated to cause the opening of the control switches successively within predetermined time intervals. q

9. In a control system, in combination, a main supply circuit, electrical devices disposed to be connected to the supply circuit, switches provided with opening and closing coils for connecting the electrical devices to the supply circuit, a plurality of tuned relays for controlling the operation of the control switches, said relays being responsive to alternating currents of predetermined frequencies superimposed upon the supply circuit, means responsive to the operation of one control switch by one of the tuned relays for rendering the other tuned relay effective when operated and maintained in the closed position for a predetermined time to cause said control switch to open, and means rendered effective in response to the opening of said control switch to cause the other control switch to be opened in response to a second operation of the tuned relay to the closed position for a different time period.

In testimony whereof, I have hereunto subscribed my name this 9th day of October,

' PAUL F. SHUEY.

for rendering one of said relays operativewhen successively energized to disconnect said devices from said circuit independently.

8. In a control system, in combination, a main supply circuit, electrical devices disposed to be connected to the supply circuit, switches provided with opening and closing coils for connecting the electrical devices to the supply circuit, a plurality oftuned relays for controlling the operation of the control switches, said relays being responsive to 'alternating currents of predetermined frequencies superimposed upon the supply cir-

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