US2295894A - System for controlling lighting circuits and like circuits - Google Patents

Description

Sept. 15, 1942. L. DEWAN ,2

SYSTEM FOR CONTROLLING LIGHTING CIRCUITS AND LIKE CIRCUITS Filed May 27, 1940 Patented Sept. 15, 1942 UNITED STATES PATENT OFFICE SYSTEM FOR CONTROLLING LIGHTING CIRCUITS AND LIKE CIRCUITS 11 Claims.

My invention relates to light control systems for indoor illumination such as disclosed in my Patent No. 2,199,394.

An object of my invention is to provide a system for turning the lights on and off with a snap action that is controlled by the change of illumination outdoors.

Another object is to provide a system for turning the lights on and oil with a snap action that is controlled automatically at predetermined hours of the day.

Another object of my invention is to provide a system for turning the lights on and off with a snap action either by change of illumination outdoors or by automatically operated mechanism indoors as desired.

Another object is to provide a system that gives a visible warning signal when the lighting units are about to be turned oif.

Another object is to provide a system that gives an audible signal when the lighting units are about to be turned off.

Another object is to provide means for turning the lighting units on simultaneously.

Another object is to provide a system in which the lighting units are under control at all times either by mechanism influenced by change of intensity of the illumination outdoors or by mechanism automatically controlled indoors.

Another object is to provide such a system in which the apparatus for controlling the lights by change of intensity of light outdoors is also used for automatically controlling the lights by mechanism indoors.

Another object is to provide a system in which the lighting units are controlled by apparatus which. may be operated selectively (l) by mechanism actuated by change of intensity of illumination outdoors, (2) by mechanism actuated by automatic means indoors, or (3) by manual means indoors as desired.

Another object is to provide a system that gives a warning signal and provides a lapse of time before the lights are extinguished.

Another object is to provide a system for controlling a plurality of lighting units in which one circuit at a time is extinguished with a time interval between the extinguishment of the various circuits.

Another object is to provide means for checking up on the lights continuously at all hours of the day and night, either by a photocell or by a time clock.

Another object is to provide means for turning off the lights slowly but for turning them on immediately.

Another object is to provide such a system that is easy and inexpensive to install and maintain.

Other objects and advantages of my improved system will be apparent from the description thereof to follow.

According to my invention, I provide a photoelectric cell in the output circuit of which is a thermionic amplifier tube. The amplifier tube is adapted to actuate a series of sensitive relays which in turn actuate a series of heavier relays. The latter heavier relays directly connect or dis connect the lighting units.

Time clock mechanism is used for automatically actuating a relay switch for controlling the circuit through the cathode heater of the amplifier tube in order to automatically turn the lighting units oil? at predetermined hours of the day. This time clock mechanism also closes a circuit through an audible signal and through a visible signal to warn that the lights are about to be extinguished. A double-throw, double-pole relay and double rectifier tube are also used in order to place the circuit in condition so that when desired the lighting units may be turned on manually all at once and not successively as normally prevails.

In the drawing,

Fig. 1 is a diagrammatic view of my improved system.

Fig. 2 is a sectional view taken through the clock mechanism on the plane of the line 22 of Fig. 1.

Referring to the drawing, a plurality of lighting units 5, 6 and 1 capable of being operated from a source of electromotive power 8 are suitably positioned in the room. The current passes through individual circuits 9, l0 and l I, respectively, and is controlled by heavy relays l2, l3 and I 4, respectively, which are adapted to be actuated by sensitive relays I5, l6 and I1, respectively, each of the latter relays being of difierent strength.

A photoelectric cell I8 is also positioned in the room so as to receive the light rays from outdoors and to be influenced thereby. This cell has a resistance element or resistor IS in its anode circuit and the cell is connected across a portion of the source of power 8.

A thermionic amplifier tube 20 is connected in the output circuit of the photoelectric cell I8. This tube is of the indirectly heated cathode type comprising a filament heater 2!, a plate 22, a cathode element 23 connected across the source and a grid 24.

The potential of the grid is controlled by the excitation of the photoelectric cell which varies the charge through resistance Hi to which it is connected and the filament heater is tapped as indicated at 22' to bias the grid.

An automatic-manual switch device 25, including an on solenoid 26, an off solenoid 21 and a movable switch member or pole 23 movable therebetween, is connected in the filament heater circuit. The movable switch member 28 is held in on or off position by a snap switch mechanism (not shown) and is capable of manual movement by hand.

The filament heater circuit comprises wires 32, 33, 34, movable pole 28, wires 35, 36, 31, resistance 33, wire 39, armature 3|, wires 43, 4| and 42.

The sensitive relays |5, |5 and H are connected in series to the plate 22 and connected in series with these relays is a contact 43 of relay 61 and a resistance 43a. The circuit of plate 22 includes wires 32, 33, relay contact 43, resistance 43a, wire 44, relay |1, wire 45, relay l5, wire 45, relay |5, wire 41, plate 22.

'The foregoing parts and elements are capable of controlling the illumination of lighting units 5, 6 and 1 through the photoelectric cell |8, and the parts are shown in position for such photoelectric cell control which is termed normal control herein.

The invention also contemplates control of the lighting units by automatic means to be substituted for or to supplement the photoelectric cell or normal control, whereby the lighting units may be extinguished at predetermined hours of the day. In the automatic means, the same relays are used.

This automatic mechanism includes a twentyfour hour electric clock device 48 of novel construction having a face plate 49 on which is mounted a split ring having separate segments 5|] and 5|. Contact screws 52 are mounted at spaced intervals in segment 55, each space as illustrated representing one hour of time, and a similar screw 53 is mounted on the segment 5|, although more may be mounted if desired.

An hour hand 54 is mounted on a collector ring 55 which is insulated from the remainder of the clock mechanism by an insulating bushing member 55. This hour hand is adapted to contact the screws 52 and 53 during its movement around the face of the clock. The segment 50 may be termed the PM segment and the segment 5| the AM segment as the hour hand 54 is intended to move over this segment 5| between the early hours of the morning and noon.

A contact 51 is mounted on the face of the clock adjacent its outer rim and another contact member 58 is also mounted on the said face in line with the contact 51 but spaced outwardly therefrom. A brush member 59 connects the ring 55 with contact 51 by means of a conductor 63. A so-called minute hand BI is insulated from the hour hand 54 and is adapted to contact the contact member 51 on its movement around the clock, once every hour.

A so-called second hand 62 makes a complete revolution every minute and is adapted to contact the contact member 58 momentarily. The minute hand 6| and the second hand 62 are connected to each other through the clock mechanism.

The clock is connected to the source of supply derstood.

by a wire 63, and the segment 50 is connected to the off solenoid 21 of snap switch 25 by wires 54 and 55, and the segment 5| is connected by wire 65 to the on solenoid 26.

The coil of the blinking relay 81 is connected in series with the clock to give a visible signal when the lights are about to be extinguished, and a buzzer device 58 is also connected in series with the clock to give an audible signal at the same time.

Mechanism is also provided for manually or automatically turning all the lighting units on simultaneously. This mechanism includes a double rectifier tube 69 of the indirectly heated cathode type having filament heaters and 1|, two plates 12 and 13 and two cathodes 14 and 15. The filament heaters are connected in series with each other and are connected across the power supply by means of a wire 13 connected to the wire 34 and a wire 11 connected to the armature 3|, a resistance element 18 being interposed between the filament heater 1| and the wire 11. late 12 is connected directly to wire 41 by means of a wire 19. Plate 13 is connected to wire 34 by means of a wire 80. Cathode 14 is connected to armature 30 by means of a wire 8|. A relay device 82 is adapted to be connected in series with the plate 13, cathode and the armature 3| by means of wires 83, 84 and 11. The armature 85 of relay 82 is connected to armature SI of relay 29 by wires 86, 4| and 40 and wires 81 and 39, and is adapted to be connected to armature by means of wire 88. A resistance element 83 is connected across the wires 83 and 11.

The operation of the system by the photoelectric cell or normal operation is as follows:

When the system is in condition for normal operation, the movable switch member 23 is initially placed in on position, that is, thrown to the right to engage the contacts of wires and 93 at the side of the magnet 25. The circuit through the filament heater of tube 23 is then completed through wires 32, 33, 34, pole 28, wires 35, 33, 31, resistance element 38, wire 33, armature 3|, wires 40, 4| and 42. The filament heater heats the cathode 23 by radiation and the heated cathode emits electrons which fiow to the plate 22 due to the plate voltage as will be un- The electron flow is controlled by grid 24. The ability of the grid 24 to control the flow of electrons is influenced and continuously varies in response to the state of excitation of the photoelectric cell |8, which is excited by the change of intensity of illumination outdoors.

When the intensity of the illumination outdoors decreases or falls below a predetermined value, the most sensitive relay I5 is energized and pulls its armature into contact with wire to energize relay |2 to pull its armature into connection with the circuit 9 thus closing the circuit through lighting unit 5 to illuminate the same.

When the intensity falls below a second predetermined value, the next most sensitive relay I6 is energized which through its armature connects wire 9| to energize relay l3 which pulls its armature into connection with the circuit l0 to close the circuit through lighting unit 5.

When the intensity falls below a third predetermined value, the next most sensitive relay I1 is energized which through its armature connee-ts wire 32 to energize relay |4 which pulls its armature into connection with the circuit H to close the circuit through lighting unit I.

When each of the relays 2, I3 and I4 is energized it pulls its respective armature up with a snap action thus bringing its respective lighting unit into circuit with a snap action as will be understood.

Conversely a return of light would cause relays |5, l6 and I! to release their armatures in order and extinguish lights 5, 6 and 1 respectively.

If it is desired to turn the lighting units off in the room at a predetermined hour of the day, for example in the evening, when it is desired to have the lights extinguished in the room, the normal photoelectric cell control is superseded by the time clock mechanism. If for example, it is desired to turn the lights oii regularly every day at 7 p. m, regardless of the intensity of the illumination outdoors, a contact screw 52 is positioned on the segment 50 in a line with the number 7 indicating the seventh hour after noon. When the hour hand 54 reaches '7 p.m. it contacts said screw 52 and when the minute hand 6| reaches and engages the contact 51 and the secnd hand 62 reaches and engages the contact 58 simultaneously or a little later the circuit through the clock is completed momentarily and once only because by the time the second hand 62 will have made another revolution the minute hand 6| will have moved beyond contact 51. This is sufiicient to close the circuit through the blinking relay 81 to pull its armature 43 over to the right whereby the lights blink momentarily. This is accomplished because resistance 43a is introduced in series with relays l5, l6 and I1 causing one or two of them to release and turn off their lights. Omission of this resistance would cause all of the lights to blink. At the same time, the circuit through the buzzer device 68 is completed and it makes an audible signal. Simultaneously, the solenoid 21 is energized thereby pulling pole 28 to the left to off position, in which position it is held by the snap switch mechanism. When the hand 62 passes contact 58 breaking the clock circuit the lights are restored by release of relay 61. Meanwhile the transference of pole 28 to the left breaks the circuit through the wire 35 and places in the filament heater circuit of tube 28, the wire 32' and resistance element 36'. The circuit through the filament heater of tube 28 then is as follows: wires 32, 32', resistance element 36', wires 36, 31, resistance 38, wire 39, armature 3|, wires 40, 4| and 42, When the current passes through the resistance element 36 in addition to resistance 38, the filament heater will gradually cool off with the result that the cathode 23 cools 01f gradually so that the most sensitive relay I! will first become deenergized permitting its armature to move away to break the circuit through the lighting unit 5 to extinguish the same. The relay l6 will next become deenergized to break the circuit through lighting unit 6, and the relay l5 will then be deenergized to break the circuit through lightin unit 1. Thus the lighting units are put out successively and slowly after an audible warning by the buzzer 68 and a visible warning by the blinking of the lights through the blinking device 61.

Thus all the lights are put out automatically at the predetermined hour of 7 p. m.

If however one wishes the lights to remain on longer after the warning signals have been given and the snap switch turned off, to the left,

it is only necessary to manually turn the switch to on position, to the right, and normal conditions will be restored and remain until the hand 54 reaches the next contact screw on the segment 50, in this case at 8 p. m. and the same procedure'of warning signals and gradual extinguishing of the lights will ensue. This of course can be repeated indefinitely. The touching of contacts at intervals during the night by the hand 54 will turn ofi the lights in case the snap switch has been left on by negligence.

If it is desired to regularly and automatically restore the normal system of control by the photoelectric cell I8, at a predetermined hour of the day, say for example at 8 oclock the next morning, a contact screw 53 is positioned on the segment 5|, in a line with the number "8 on the clock face indicating the eighth hour after midnight. The hour hand 54 is adapted to contact said screw 53, and when the minute hand 6| and second hand 62 will have reached and engaged the contacts 51 and 58, the circuit through the clock and on solenoid 26 will be completed 7 through wire 66 thereby energizing said solenoid 26 and pulling the movable pole 28 over to the on position at the right to bring the wire 35 into the circuit of the filament heater or tube 20 and to shunt out of circuit the resistance element 36' thereby restoring the original temperature of the cathode and with it photoelectric cell or normal control.

The feature whereby all the lights go on at once when the master switch 25 is turned on is carried out by an automatic operation whenever the switch is turned off, putting the mechanism in a condition for thi action when the switch is turned on again. The operation is as follows:

The lights having been extinguished due to the movable pole 28 being thrown to the left to off position, the pole remains in such off position due to the snap switch mechanism. The armatures 30 and 3| have also been thrown to the left with pole 28 by disconnection of coil 29 and re lease of armature. Armature 3| is now in engagement with contact of wire 11 and th heaters 10 and H of tube 69 are in circuit. However, relay 82 still connects the filament heater of tube 20 to the negative side of the supply. As tube 69 is a slow heating tube, it slowly becomes conductive and slowly energizes relay 82, and relay 82 finally pulls armature 85 over to the right disconnecting the filament heater and cathode of tube 20. This happens when all, or nearly all, of the relays 5, l6 and I! have already been released. Tube 69 remains activated as long a th switch 28 is in off position.

, This creates a condition such that if pol 28 is moved manually or automatically back to on position, the tube 28 is shunted out of circuit and the relays l5, l6 and l! are connected to the negative side of the supply through wire 19, plate 12 and cathode 14 of tube 69, Wire 8| and armature 30 of relay 29 which is now on the right, wire 88, armature 85, wires 86, 4| and 42 so that said relays l5, l6 and I! receive a strong current independently of the plate 22 of tube 20. The circuit is completed through the relays l5, l6 and H to the positive side of the supply through wire 44, contact 43, wires 33 and 32. This cuts out the tube 20 and the current flows directly through the relays |5 I6 and [1 whereby said relays are energized simultaneously thereby moving their armatures all at once to close all of the circuits simultaneously and thus turning all the lights on at once. At the same time, pole 3| of relay 29 now connects the filament heater of tube 25 to the negative supply while the heaters and H of tube 69 are still connected to the supply by relay 82 which is still energized, but the heater I6 is now in series with resistance 83 so that cathode temperature of tube 69 very slowly falls. Thus relay 82 will slowly be deenergized and finally disconnect relays l5, I6 and I! from wire 19 for direct negative supply. This does not happen until the cathode 23 of tube 29 is heated sufficiently to allow tube to regain normal photoelectric cell control. The heater 76 of tube 69 i now entirely disconnected.

The temperature lag of the heaters of tubes 20 and 63 should be similar. If greater delay in action is required or if the amplifier tubes are of the directly heated cathode type, both resistances as and 18 should be of the ballast type elements whose resistance slowly rises when energized and have approximately similar temperac ture ag characteristics.

I claim:

1. In a system for controlling illumination, a source of electromotive power, a li hting unit in circuit therewith, a plurality of relay devices for controlling said circuit and mechanism for selectively actuating said relays either by a photoelectric cell iniluenced by change of intensity of natural illumination or by a time clock at a predetermined hour whereby the relay devices are actuated successively either by the photocell or by the time clock.

2. In a system for controlling illumination, a source of electromotive power, a lighting unit in circuit therewith, a relay for controlling the lighting unit circuit, a second relay for controlling the first named relay, a photoelectric cell, a cloclr, means for gradually varying the strength of the second relay circuit according to the photoelectric cell excitation and means independent of the photoelectric cell for radually varying the strength of the second relay circuit according to the clock movement.

3. In a system for controlling illumination, a source of electromotive force, a lighting unit in circuit therewith, a photoelectric cell, an electronic amplifier therefor, a translating device in the amplifier output circuit to control the lighting circuit, means for varying the amplifier output in accordance with the photoelectric cell excitation to control the translating device accordingly, and clock means independent of the photoelectric cell and acting on the electronic amplifier for varying the amplifier output to control the translating device and the lighting circuit in accordance with time.

4. In a system for controlling illumination, a source of electromotive force, a lighting unit in circuit therewith, a photoelectric cell, an electronic amplifier therefor, a relay controlled by the amplifier and controlling the lighting unit circuit, a switch for acting upon the cathode of the amplifier for controlling the output thereof and the relay and thereby controlling the lighting unit independently of the photoelectric cell control.

5. A circuit control apparatus including a photoelectric cell, a clock, an electron valve, a translating device controlled thereby, means for varying the output of the electron valve according to the photoelectric cell excitation and means independent of the photoelectric cell acting upon the electron valve for varying its output according to the clock movement.

6. A lighting circuit control apparatus includ ing an electron valve having a grid, a cathode and an anode, a circuit controlled thereby, means including a photocell for controlling the circuit in accordance with natural light by varying the grid charge and means independent of the first means for controlling the circuit by varying the cathode temperature in accordance with time.

7. A clock controlled apparatus including clock mechanism, an electron valve, a circuit controlled thereby and means for varying-the temperature of the cathode of said electron valve in accordance with the clock movement.

8. In a ystem for controlling illumination, a source of electromotive power, a lighting unit in circuit therewith, a photoelectric cell, an amplifier, a translating device and circuit therefor and clock mechanism including a switch automatically controlled thereby for deenergizing the circuit of the translating device according to predetermined time and means whereby said switch may be reset manually for restoring the circuit of the translating device.

9. In a system for controlling illumination, a source of electromotive power, a lighting unit in circuit therewith, a relay device in saidcircuit, a thermionic tube controlling said relay, time clock mechanism in circuit with said tube controlling the same whereby the lighting unit is lit or extinguished and a device in circuit with and controlled by said clock mechanism for producing an audible signal at an interval before the lighting unit is extinguished.

10. In a system for controlling illumination, a source of electromotive power, a plurality of lighting circuits, and clock mechanism for breaking the circuits whereby when the clock operates at a predetermined time the circuits are broken successively within intervals of at least several seconds duration by apparatus independent of the movement of the clock.

11. In an illumination control system, a source of electromotive power, a lighting unit in circuit therewith, a photocell, a time clock, an amplifier, a relay for switching the lighting unit, a second relay whose contacts are in circuit with and energize the coil of the first named relay and which is controlled by the amplifier whose output is varied gradually by either the time clock or the photocell.

LEON DEWAN.

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