US2476330A - Relay control means and starting means for gaseous lighting devices - Google Patents

Description

July 19, 1949. slTzER 2,476,330

P. RELAY CONTROL MEANS AND STARTING MEANS FOR GASEOUS LIGHTING DEVICES Filed March 22, 1944 fied f ER INVENTOR ATTORNEY 5 Patented July 19, 1949 RELAY CONTROL MEANS AND STARTING MEANS FOR GASEOUS LIGHTING DE- VICES Philip Sitzer, Irvington, Sol Lamp Works, Inc.,

tion of Delaware N. J., assignor to Tung- Newark, N. J., a corpora- Application March 22, 1944, Serial No. 527,654

11 Claims.

This invention relates to relays and relay circuits and control systems including the same.

One object of the invention is a novel and improved relay and relay control for starting a gaseous discharge device.

More particularly the invention is particularly applicable to the starting of conventional fluorescent lamps wherein at starting a relatively large value of current flows and it is required that the control be adjusted to delay its action for approximately one second or longer and, on the other hand, the contacts be held open during normal operation of the lamp notwithstanding the reduction in current flowing during normal operation of the lamp.

An object of the invention is a simple and inexpensive starting control for lamp-s of this character which is characterized by operative functioning to accord exactly with the demands of a starter of this character.

A further object of the invention is a novel and improved thermal starting control of the above indicated character.

A further object of the invention is a novel and improved magnetic control of the above indicated character.

A further object of the invention is a novel land improved starting control of the above indicated character for a normally closed starting circuit.

A further object of the invention is a starting control of the above indicated character for a Vnormally open starting circuit.

A further object of the invention is a novel and improved relay and relay control.

Further objects of the invention will hereinafter appear.

For a better understanding of the invention reference may be had to the accompanying drawings wherein Fig, 1 is a diagram of a relay circuit illustrating the principle of the invention;

Fig. 1A is a circuit diagram of a control system embodying the modification of Fig. l;

Fig. 2 is a diagram illustrating the modified relay embodying the principle of the invention;

Fig. 2A is a circuit diagram of a control system embodying the modification of Fig. 2;

Fig. 2B is a graph illustrating the functioning of a relay embodying the invention of Figs, 2

and 2A;

Fig. 3 is a circuit diagram of la modified starting means for gaseous discharge lamps.

Referring to Fig. 1 of the drawings, I have illustrated one embodiment `of my improved relay comprising switch control contacts I0 which are thermally controlled, the details of the thermal mechanism being omitted for convenience in illustration. The thermal mechanism is controlled by a heater element Il which is energized by the current flowing in the circuit I4, I5. A resistance element 20 is connected in parallel with the heater element II. The heater element II of the thermal relay is made of a material or metal with a high positive temperature co-efiicient of resistance, as for example of a wire of tungsten, iron, nickel, etc. which have positive temperature coefficients of resistance. The resistance element {it}` has very little or no positive temperature coefficient, as for example, being made of a wire of a metal such as Nichrome which has little or no resistance change with changes in temperature or changes in volume of current ilowing. The action is such that there will be less percentage change of current through the heater element II for any change of current flowing in the circuit I4, I5 than there would be without this particular arrangement. This voccurs because of the large change in resistance in the heater element I I with changes in current due to its positive temperature coefiicient of resistance, that is with increase in current there is an increase in temperature which causes the resistance of the heater element II to become greater, thereby causing a greater percentage or proportion of the total current owing in the circuit I4, I5 to flow through the shunt resistor 20 and vice versa. By making the shunt resistor element 2U of some material, alloy or metal which has a negative temperature coefficient of resistance, such as carbon, or which has negative resistance characteristics such as certain of the silicon carbide compounds, namely by having the resistance of the shunt element 20 vary inversely with respect to the resistance of the heater element I I a still greater differential in the current flowing in the two elements is obtained with changes in the total current flowing. With this arrangement changes in the total current flowing in the circuit I4, I5 are reflected to a substantially lesser extent in the element II, that is the percentage change in the current flowing in the element Il is substantially less than the percentage change in the total current flowing.

The invention is particularly applicable to the starting of gaseous discharge devices, such for example, as the fluorescent lamp A illustrated in Fig. 1A.

The fluorescent lamp A is provided with the conventional heating elements I2 at each end of the tube and in the conventional manner the heaters I2 of the lamp are connected in series with a conventional transformer choke I3. The heater element II of the thermal relay is connected in series with the line I4 from one side of the circuit, the line I5, the two heating eleinents I2 and the line I6 leading to the other end of the choke coil I3. The heaters l2 are connected on one side by the wires Il to the switch contacts I of the thermal relay and a conventional condenser I8 is shown connected across the switch contacts I0. The switch contacts Ill are normally closed, that is closed when the line switch I9 is open or the lamp A is not operating. When the line switch I9 is closed starting current flows through the circuit, heating the filaments I2 at each end of the lamp and also the heater element II of the thermal relay. After a suitable time delay the contacts I0 of ,the relay snap open and if the lamp lights by discharge between the elements I2 these switch contacts I0 are retained open due to the running current of the lamp which flows through the heater element I I of the relay.

This control is effected notwithstanding the large change in the volume of current ilowing in going from starting condition to the running condition, for example with .8 of an ampere owing at the initial starting the time delay of say, one second, for heating the heaters I2 may be ob- Itained before the switch contacts IU are opened `and even though the current iowing in the circuit during the normal operation of the lamp should drop to half or below, say to .25 ampere for normal running, the heater element is sup- ',plied with a suillcent current to hold the contacts IIJ open against the bias tending to close them.

Any suitable type of thermal switch may be employed as for example the bimetallic type or .the vane type. In either case the heating element II is preferably enclosed in an evacuated envelope II so as to prevent oxidation of the element at high temperatures at which the element should be run for best results. An example of the vane type of switch which may be used is illustrated in Fig. 8 of Schmidinger Patent 2,133,309 wherein the switch contacts 39 and 44 are the contacts I0 of this application and the heater element 43 is the heating element I I of the application.

A modified relay and circuit control is illus- 'trated in Fig. 2. The circuit is indicated at I4, i5, the thermal relay contacts are indicated at I0 and the heating element for the thermal switch device is indicated at 2|. The heater ZI has connected in series with it a resistance element 25 having a positive temperature coeiiicient such for -example as of tungsten, nickel or iron and a resistance element is connected in shunt of the character described above with respect to Fig. 1 land Fig. 1A. For example, the resistance element 20 may be of Nichi-.ome or other resistor element with a fairly constant resistance with temperature changes, or it may have a negative coefcient, and as indicated, the series combination consisting of the resistor element and the Iheater element 2I of the thermal relay is connected in parallel with the element 20. The element 25 is placed .in an evacuated envelope such as the envelope II' of Fig. 1A so that it is not oxidized or harmfully affected in any manner when heated to a red or white heat. The action of this control is to allow a greater percentage of -the total current flowing to pass through the heater element of the thermal relay, when the total current is low in value than at higher valuesof total current, namely at low values of current the element 25, such for example as of tungsten. wire, has a proportionately low value of electrical resistance. At higher values of current the resistance of the tungsten element increases at a much greater proportionate rate than the resistance of the other elements of the circuit which decreases the proportional amount of the total current that ilows in the path composed of the tungsten heater element 25 and the heater element 2 I. The heater element 2| is of course oi a character so as not. to oppose the controlling function of the element 25, namely the element 2I must not have an appreciable negative coeicient at least in sulcient amount taking into consideration the proportions of the resistance elements 2I and 25 to offset the stabilizing effect of the element 25 with changes in total current flowing. The element 20 is a resistance either having no appreciable positive temperature coefiicient or one having a negative coefficient. In the circuit of Fig. 2 and Fig. 2A, the temperature coefficient of the heater 2l as indicated need not be a high temperature coeiiicient since the element 25 imparts the desired high temperature coeiilcient characteristic to the circuit including the heater 2 I Fig. 2B illustrates graphs of the currents ilowing in the heater branch of the parallel circuit and in the shunt or ballast branch containing the element 20. The abscis'sas represent total currents and the ordinates represent the current owing in each of these branches. The lower curve represents the current flowing through the heater 2I and the tungsten resistor element 25 and the upper curve represents the current owing in the ballast or shunt circuit containing the resistor element 20. This shows that with changes in total current flowing the percentage change in the heater branch of the circuit is much smaller than the changes in the total current flowing, thereby rendering the thermal switch mechanism much less sensitive to changes in current flow. For example, for values of total current above 0.25 ampere with the particular combination of resistances upon which the graphs are based the current in the heater element branch changes only a slight amount for much larger variations in the total current ilowing. These graphs are based upon the test results of a circuit in which the element 2| was a pull wire in a vane type thermostatic switch made of 0.0065 Ohmax, the element 25 was a standard T67 lamp and the element 20 was of 17.82 .010 Nichrome wire. The graphs indicate that the operational range of such a control unit can be increased greatly without substantially affecting its operation. For example, it can be effectively used to control any fluorescent lamp within a wide range of capacities, as for example, fluorescent lamps of -capacitiesfrom 15 watts to 40 watts sizes. For example, it is found by actual test that the operating time for the thermal switch was 0.82 second at 0.87 ampere total current and 3.07 seconds at 0.488 ampere total circuit current.

In Fig. 2A I have illustrated the embodiment of the invention of Fig.v 2 as used in the starting of a fluorescent lamp similar to that illustrated in Fig. 1. In thisl embodiment the operating or heater element 2| for the relay contacts I0 has connected in series with it av resistance element 25 having a positive temperature resistance co- Awhen heated to red or white heat.

eiiicient such as that of tungsten, iron, nickel or other material having such a characteristic. A

Nichrome or other resistor element 20 having a the heater element 2| of the thermal relay. The

element 25 is preferably placed in an evacuated or gas-filled container such as the container II described above in Fig. 1A or else is otherwise protected in any suitable manner so as not to be oxidized or harmfully affected in any manner The action of this arrangement is to allow a greater percentage of the total current flowing to pass through the element 2| of the relay when the total curvrent is low in value than at higher values of current.

At low values of current the element 25 has a proportionately low value of electrical resistance, whereas at higher values of current the f resistance of the element 25 increases at a much vgreater proportional rate than the resistances of the other elements of the circuit. This decreases the proportional amount of total current that lflows in the path composed of the tungsten resistance 25 in series with the relay heater filament.

The operation generally of the control of Fig. 2A is similar to that described above with respect to Fig. lA, namely after the starting of the iluorescent lamp A the heating element 2| has suflilcient power to hold the contacts I open notwithstanding the reduced flow of current through Vthe circuit I4 and I5 when the lamp is operating.

The heater element 2| may be a pull Wire or the -ous discharge device is illustrated as of the conventional fluorescent lamp type having a heater electrode I2 at either end thereof. The supply lline is indicated as having a chokecoil I3 connected in one side thereof and the line as connected with one end of the heater electrodes I2.'

The other ends of the heaters I2 are connected through the lines 30 and 3| with the contacts 3 of the thermostatic switch. The contacts 3 are fnormally open, biased to open position, namely open when the switch I9 in the supply line is open `and also open durin-g the normal operation of 'the fluorescent lamp A. These contacts 3 however are closed ymomentarily at starting by the heat delivered by the element 4. The element 4 is a heater of a metal having a high positive 'temperature coefficient, such as tungsten, iron or nickel, etc. and the element 5 is a resistance either having no appreciable positive temperalture coeflicient, such as of Nichrome or having Va negative temperature coeflicient, such as carbon or the silicon carbide compounds. The resistance of element 5 is much larger than that of resistance 4 so as to predominate thereover, as :for example being 75% to 90% of the sum of the itwo. During the normal operation of the lamp the elements 4 and 5 are connected across the electrode heaters I2 and accordingly the voltage drop across the lamp A is supplied to these two elements in series. The 12R. power of the element 4 is insuiiicient to close the contacts 3' with only the voltage vdrop of the lamp A applied to the elements 4 and 5. 4At starting, however, namely when the switch I9 is first closed substantially the full line voltage v.) is supplied to the resistances I2 and the elements 4 and 5 and the heating power of the element 4 is then very substantially increased by reason of the relative proportioning and character of the two elements 4 and 5 as described above. This increased power results in the closing of the contacts 3 and the short-circuiting of the elements 4 and 5 and the consequent reopening of the contacts 3 which are biased to the open position against the heating effect of the element 4. The short-circuiting of the elements 4 and 5 puts the heaters I2 directly across the line with the resultant increased heating of these electrodes so that when the contacts 3 are opened after the momentary closure thereof the desired starting kick is delivered to the lamp A. The voltage drop, as indicated, in the lamp A is then insuiiicient to close the contacts 3 against the bias. Thus by rendering the thermal switch sensitive to the full line voltage but not sensitive to the voltage drop across the lamp A to close the contacts 3' a very simple and inexpensive starting mechanism is provided for the lamp. A conventional condenser IB is connected across the contacts 3'.

I claim:

l. In a control means for a gaseous discharge device having heating elements therein, a circuit connecting said heaters in series across a supply line, a switch in said circuit which is thermally controlled, a controlling element for said switch which is energized by the current flowing through said circuit and through the gaseous device, a resistor element in parallel with said controlling element, the coeii'cients of said elements being related to each other in a manner to differentially proportion variations in the current flowing in the circuit to shift greater changes in current flow to the resistor element.

2. In a control means for a gaseous discharge device having heating elements therein, a circuit connecting said heaters in series across a supply line, a switch in said circuit which is thermally controlled, a controlling element for said switch which is energized by current flowing through said circuit and through the gaseous device, a resistor element in parallel with said controlling element, the coeiicients of said elements being related to each other in a manner to differentially proportion variations in the current flowing in the circuit 'to shift greater changes in current ow to the resistor element, said switch being opened by the current flowing through the operating element.

3. In a control means for a gaseous discharge device having heating elements therein a circuitconnecting said heaters in series across a supply line, a switch in said circuit which is thermally controlled, a thermal element for controlling said switch which is energized by part of the current fiowing through said circuit and through the gaseous device, yand a resistor element connected in multiple with a circuit including said thermal element so as to be energized by a part of the current flowing in said rst-named circuit with the resistances of the multiple paths of the currents through the two elements varying differentially with respect to each other upon variations of current flow to shift greater changes in current flow to the resistor element.

4. In a control means for a gaseous discharge dev-ice having heating elements therein a circuit connecting said heaters in series across asupply line, a switch in said circuit which is thermally controlled, a thermal element for ycontrolling said switch which is energized by part of the current -iiowing through said circuit and through the gaseous device, and a resistor element connected -in multiple with a circuit including said thermal element so as to be energized by a part of the vcurrent flowing in said-first named circuit with ythe resistances of the multiple paths of the currents through the two elements varying differentially with respect to each other upon variations 'of current flow so as to cause a smaller variation of current flowing through the thermal eleiment than that flowing through the resistor elevment.

5. In a control means for a gaseous discharge ldevice having heating elements therein a circuit connecting said heaters in series across a supply line, a switch in said circuit which is thermally controlled, a thermal element for controlling said switch whichis energized by part of the cur- -rent flowing through said circuit and through 'the gaseous device, and a resistor element connected in multiple with a circuit including said thermal element so as to be energized by Ia part of the current flowing in said first-named circuit with the resistances of the multiple paths of the lcurrents through the two elements varying differentially with respect to each other upon varia- .tions of current iiow, the thermal element hav- .ing a positive temperature resistance coeicient and the resistor element having no appreciable positive temperature resistance coefiicient.

6. In a control means for a gaseous discharge ydevice having heating elements therein, a circuit connecting said heaters in series across a supply line, a switch in said cir-cuit which is thermally controlled, a thermal element for controlling said vswitch which is energized by part of the current owing through said circuit and through the gaseous device, and a, resistor element connected in multiple with a circuit Iincluding said thermal element so as to be energized by a part of the current iiowing in said first-named circuit with the resistances of the multiple paths of the currents through the two elements varying differentially with respect to each other upon variavtions of current flow to shift greater changes in current iiow to the resistor element, a resistance having a yhigh temperature resistance coeihcient being connected in series with the thermal element.

7. In a control means for .a gaseous discharge device having heating elements therein, a circuit connecting said heaters in series across a supply line, a normally open switch in said circuit, ther- -mal means for closing said switch at the starting of the gaseous discharge device comprising a heating element and a resistor element connected across said switch, said switch `heating element being of a substantially smaller resistance than that of the series resistor and said heater having 4a positive temperature coeiiicient of resistance and said resistor element having no appreciable positive temperature coeiiicient of resistance.

8. In a control means for a gaseous discharge device having heating elements therein. ,a circuit connecting said heaters in series :across a supply line, a switch in said circuit which is thermally controlled, a thermal element for controlling said switch which is energized by part of the current iiowing through said circuit and through the 'gaseous device, and a. resistor element connected in multiple with a circuit including said thermal element so as tov be energized by :a part of the current flowing in said first named circuit with the resistances of the multiple paths of the currents through the two elements varying differentially with respect to each other upon variations of current now with the resistance of the circuit which is in multiple with said resistor element having a high positive temperature coeicient andv with the resistor element having little or no positive temperature coeicient.

9. In a control means for a gaseous discharge device having heating elements therein a circuit connecting said heaters in series across a supply line, a switch in said circuit which is thermally controlled, a thermal element for controlling said switch which is energized by part of the current flowing through said. circuit and through the gaseous device, and a resistor element connected in multiple with a circuit including said thermal element so as to be energized by a part of the current flowing in said rst named circuit with the resistances of the multiple paths of the currents through the two elements varying differentially with respect to each other upon variations of current flow with the resistance of the circuit which is in multiple with said resistor element having a high positive temperature coefficient and with the resistor element having little or no positive temperature coefficient and with the thermal element having little or no positive temperature coeiiicient and a resistance in series therewith having a high temperature coefficient.

l0. Starting means for a discharge lamp having a pair of starting iilaments adapted to be Connected across a supply line during the starting operation, the combination of a thermally controlled two-position switch in series with the iilaments adapted in one position toenergize them for starting, a thermal element having a high positive temperature coeiiicient of resistance connected in series with the filaments for operating the switch at starting, and a resistor having 45 no appreciable positive temperature coefficient of resistance connected with the thermal element, said resistor and element being continuously in circuit with the supply line to be heated thereby during both starting and normal operation with 50 the heating current through the thermalr element during normal operation of the lamp being substantially lower than that during starting.

11. Starting means for a discharge lamp having a pair of starting iilaments adapted to be 55 connected across a supply line during the starting operation, the combination of a thermally controlled two-position switch in series with the filaments adapted in one position to energize them for starting, a thermal element having a 60 high positive temperature coeliicient of resistance connected in series with the filaments for operating the switch at starting, and a resistor having no appreciable positive temperature coefficient of resistance connected with the thermal 65 element, said resistor and element being continuously in circuit with the supply .line to be heated thereby during both starting and normal operation with the heating current through .the thermal element during normal operation of the 70 lamp being substantially lower than that during starting, the switch being normally open.

PHILIP SITZER,

(References on following page) REFERENCES CITED Number The following referenlces are of record in the le of thls patent: 135641938 UNITED STATES PATENTS 5 1,728,551 Number Name Date 603,594 Cutler May 3, 1898 212 812 6 721,381 Potter Feb. 24, 1903 313391031 862,740 Kallman Aug. 6, 1907 23 9307 1,146,927 conrad July 20, 1915 10 J 3 Woodbridge May 8, 1917 10 Name Date Simon Dec. 16, 1919 Sullivan Apr. 4, 1922 Chandeysson Dec. 8, 1925 Jennings Sept. 17, 1929 Meyer May 14, 1935 Peters July 15, 1938 Frech Mar. 31, 1942 Cates Jan. 11, 1944 Warsher Jan. 18, 1944

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