US2355476A

US2355476A - Fluorescent lamp starter

Info

Publication number: US2355476A
Application number: US448240A
Authority: US
Inventors: Roy M Smith; John R Steegstra
Original assignee: Bryant Electric Co
Current assignee: Bryant Electric Co
Priority date: 1942-06-24
Filing date: 1942-06-24
Publication date: 1944-08-08
Anticipated expiration: 1961-08-08

Description

1944- R. M. SMITH ETAL 2,355,476

, FLUORESCENT LAMP STARTER Fi led June 24, 1942 INVENTORS R. M SM/T/r J? .5? 6775 ATTORNEY Patented Aug. 8, 1944 UNITED STATES PATENT OFFICE FLUORESCENT LAMP STARTER Application June 24, 1942 Serial No. 448,240

8 Claims.

The present invention relates to gaseous discharge lamps and particularly to a relay for the starting and operating of such lamps of the fluorescent type from the usual source of electrical energy of the customary domestic potential.

It is customary with lamps of this type to connect thefllamentary electrodes in series with an inductance element across the domestic source of supply, and a relay device such as shown in Patent 2,200,443, issued May 14, 1940, to E. C. Dench, is employed to first connect the filamentary electrodes in a series heating circuit to raise the temperature thereof to electron emissivity, after which the relay operates to interrupt the series heating circuit and causes a high voltage surge from the series-connected inductance, which thus initiates a discharge between the preheated electrodes.

The difiiculty with such circuit arrangement resides in the fact that if the discharge lamp becomes defective, such as by loss of the electronemissive material from the electrodes, and the discharge accordingly fails to start for any reason, the relay continues to operate indefinitely, thus not only shortening its useful life but since it repeatedly completes and interrupts the series heating circuit of the filamentary lamp electrodes.

the latter will intermittently glow and constitutes a source of annoyance to the user with attendant waste of electrical energy.

It is accordingly an object of the present invention to provide a starting and operating arrangement for a gaseous discharge lamp wherein a relay unit is employed to initiate a discharge in the lamp while consuming an insignificant amount of energy during operation of the latter, and which relay unit operates to prevent glowing oi' the lamp electrodes by locking out the lamp in the event a discharge is not initiated therein after several operations of the relay.

Another object of the present invention is the provision of a relay unit for starting and operating a gaseous discharge lamp which can be readily inserted in the starter socket and is operable to initiate a discharge in the latter while consuming an insignificant amount, of energy once such discharge is started; but in the event the lamp becomes detective, the relay operates to "lock out" the lamp and is automatically returned to its normal position upon replacement of the defective lamp.

Still further objects of the present invention will become obvious to those skilled in the art by reference to the accompanying drawing wherein: Fig. 1 is a sectional view in elevation of the relay unit of the present invention and showing the relative arrangement of the various parts:

geport, Conn, a corpo- Fig. 2 is a fragmentary sectional view or the relay unit of the present invention identical to Fig. 1 except that it shows the position of the various parts when the relay is in the lamp lockout" position;

Fig. 3 is a sectional view taken on the line IIIIII of Fig. 1 and looking in the direction indicated by the arrows, and

Fig, 4 is a schematic diagram of the starting and operating circuit for a discharge lamp and employing thenovel relay unit of the present invention.

Referring now to the drawing in detail, the relay unit 4 shown in Fig. 1 comprises a casing 6 of a plastic material or light metal permanently closed at one end and having its other end closed by an insulating cap 6 provided with a pair of socket terminals I and I and held in place as by bent lugs 5 protruding from the casing 5. Disposed within this casing is a glow switch Ill of the type shown in Patent 2,228,210, issued January '7, 1941, to R. F. Hays, Jr., comprising a vitreous envelope provided with an ionizable medium at a suitable pressure and having a pair of electrodes l2 and I3 (Fig. 4), one 01 which I2 is a bimetallic element. A radio frequency suppressing condenser I4 is also housed within the casing 5 and is connected in shunt across the glow switch iii.

In addition, a thermal relay is supported withing the casing 5 by the insulating cap 6. This thermal relay comprises a bimetallic element l5 anchored at one end to the insulating cap as by projections i8 thereon passing through apertures 3| gripping that portion of said cap therebetween.

The element i5 is bent upon itself to form a corrugation, with its other end carryin a contact l1 normally engaging a contact [8, the latter of which is supported by an eyelet or the like lil passing through the insulating cap 6. A low resistance heater element 20 is wound about the bimetallic element i5, but insulated therefrom by a sleeve of heat resistant material such as asbestos or the like 22, with one end of this low resistance heater element being'connected directly to the socket contact terminal 1, while its remaining end is connected directly to the bimetallic element I 5, as can be appreciated from Fig. 4.

The stationary contact terminal I8 is in turn connected to the electrode l3 of the glow switch by a conductor 23, while the bimetallic electrode ll of the glow switch is connected to the remain ing socket contact terminal 8 by a conductor 24. A high resistance heater element 25 is disposed beneath the corrugation formed in the bimetallic element with its ends connected respectively to the socket contact terminals 1 and I, which thus disposes the high resistance heater element normally in a shunt circuit with the glow switch l2, condenser H, bimetallic element II together with the contacts IT and I8, as well as the low resistance heater element 20.

Referring now more particularly to Fig. 4, a starting and operating circuit is shown for initiating a discharge in a discharge lamp and employing the relay of the present invention as above described. The discharge lamp 2. is provided with filamentary electrodes 21 and 28. As shown, one end of the filamentary electrode 21 is connected through an inductance element 29 to one side Li of a source of customary domestic potential of l-230 volts. Likewise, one end of the filamentary electrode 2! is connected through a switch 30 to the other terminal of the supply source L2. The remaining ends of the filamentary lamp electrodes 21 and 28 are connected together by the relay unit 4. Upon closure of the switch 30, a series heating circuit for the filarnentary lamp electrodes 21 and II is completed from the supply source LI through the inductance element 29, filamentary electrode 11, to the socket terminal 8, and thence through the glow switch l0, normally closed contacts I! and il, bimetallic element l5, low resistance heater element to the socket terminal I, and thence through filamentary electrode 20 and switch II back to the other supply terminal L2.

Thus, substantially the full potential of the supply source LIL2 is impressed across the electrodes l2 and I! of the glow switch II, which voltage is sufficient to initiate a glow discharge between the electrodes l1 and II. This discharge accordingly heats the bimetallic electrode i2, causing it to deflect into engagement with the electrode 13, thus positively completing a series heating circuit to the filamentary lamp electrodes 7 and 28, allowing them to be very rapidly raised to an electron-emitting temperature.

By the time these latter electrodes have reached an electron-emitting temperature, the bimetallic electrode I! of the glow switch I. will have cooled, disengaging the electrode ii and returning to its normal position. Disengagement of the glow switch electrodes i2 and I! will cause a high voltage surge or kick from the inductance 29, which thus initiates a discharge across the preheated lamp electrodes 21 and II. If for any reason a discharge is not initiated in the discharge lamp 26 upon initial operation of the glow switch it, it will repeat its operation a number of times until such discharge is finally initiated. Once such discharge is initiated, only lamp voltage is impressed across the electrodes l2 and I! of the glow switch H) which is insufficient to again cause a glow discharge, with the result that the entire glow relay unit 4 consumes very little energy during operation of the lamp.

If the discharge lamp II has become defective, such as by the filamentary lamp electrodes 21 and 28 having lost their electron-emissive coating, the glow switch i0 will continue its repetitious operation for a predetermined period of time. The continued application of substantially the full potential of the source of supply Ll--L2 to the glow switch in for this predetermined period of time will cause the low resistance heater element 20 to gradually heat the bimetallic element I! through the asbestos insulation 21. when the bimetallic element 20 reaches the proper temperature, it deflects and opens the contacts ll and II, as shown in Fig. 2, which thus interrupts the series heating circuit for the filamentary electrodes 21 and 2|, as well as the circuit to the glow switch II and the low resistance heater element 20.

The high resistance heater element 25 which was formerly in a shunt circuit with the glow switch II and low resistance heater II is now impressed with substantially the full potential of the source of supply LI-LI, and while it draws negligible current, nevertheless sumcient heat is produced by this high ohmic resistance heater 25 to heat the bimetallic element ii and maintain the contacts I! and II in an open position, thus "locking out" the defective lamp 2..

Interruption of the circuit to the glow switch It by maintaining the contacts I! and II in an open position prevents continued operation of the glow switch II in a futile attempt to initiate a discharge in the defective lamp 2.. However, upon replacement of the defective lamp, the circuit is then broken to the high ohmic resistance heater element II which thus allows the relay unit to return to its normal position preparatory to performing its cycle of operation to initiate a discharge in the lamp 2 in the manner above described.

It thus becomes obvious to those skilled in the art that a simple yet efficient circuit arrangement is provided by the present invention wherein a relay unit is employed for the starting and operating of a discharge lamp, particularly of the fluorescent type. Moreover, when the lamp becomes defective and will accordingly not start after a predetermined period of time following initial operation or the relay unit, the latter automaticallv operates to "lock out" the defective lamp, which thus in effect disconnects the latter from the source of supply, thereby preserving the useful life of the relay unit and at the same time eliminating annoyance of continued glowing of the filamentary lamp electrodes. Furthermore, the amount of energy consumed by the relay while in its lock-out" position is negligible regardless of the time such relay remains in its locked-out" position until the defective lamp is replaced.

Although one specific embodiment of the present invention has been shown and described, it should be understood that other modifications thereof may be made without departing from the spirit and scope of the appended claims.

We claim:

1. In combination, a gaseous electric discharge lamp containing a thermionic cathode and a cooperating electrode, and a starting and operating circuit therefor comprising an inductance. means connecting one end of said thermionic cathode and said cooperating electrode across the terminals of a current source in series with said inductance, and a relay device connected across the opposite end of said thermionic cathode and to said electrode for initiating a discharge in said lamp and for locking out said lamp in the event the same becomes defective comprising a glow discharge device operable to initiate a discharge in said lamp, a relay including actuating means included in series with said glow discharge device and a pair of normally closed contacts for completing a circuit to said actuating means and to said glow discharge device and operable by said actuating means only upon continued operation of said glow discharge device for a predetermined period of time to cause opening of said contacts, means normally connected in a shunt circuit with said glow discharge device and said actuating means and operable upon opening of said contacts to maintain said contacts in an open position and interrupt the circuit to said glow discharge device when said discharge lamp becomes defective, and said last mentioned means being automatically operable to cause closure oi said contacts and restoration of said relay device for normal operation upon replacement of the detective lamp.

2. In combination, a gaseous electric discharge lamp containing a thermionic cathode and a cooperating electrode, and a starting and operating circuit therefor comprising an inductance, means connecting one end of said thermionic cathode and said cooperating electrode across the terminals of a current source in series with said inductance, and a relay device connected across the opposite end of said thermionic cathode and to said electrode for initiating a discharge in said lamp and for locking-out said lamp in the event the same becomes defective comprising a glow discharge device operable to initiate a discharge in said lamp, a relay including actuating means included in series with said glow discharge device and a pair of normally closed contacts for completing a circuit to said actuating means and to said glow discharge device and operable by said actuating means only upon continued operation of said glow discharge device for a predetermined period of time to cause opening of said contacts, a high resistance heater element normally connected in a shunt circuit with said glow discharge device and said actuating means and operable upon opening of said pair of contacts to maintain said contacts in an open position and to interrupt the circuit to said glow discharge device to prevent operation of the same in a futile attempt to start said discharge lamp when the latter becomes detective, and said high resistance heater being automatically operable to cause closure of said contacts and restoration of said relay device for normal operation upon replacement oi the detective lamp.

3. In combination, a gaseous electric discharge lamp containing a thermionic cathode and a cooperating electrode, and a starting and operating circuit therefor comprising an inductance, means connecting one end of said thermionic cathode and said cooperating electrode across the terminals of a current source in series with said inductance, and a relay device connected across-the opposite end of said thermionic cathode and to said electrode for initiating a discharge in said lamp and for locking-out said lamp in the event the same becomes defective comprising a glow discharge device operable to initiate a discharge in said lamp, a relay including a bimetallic element and a resistance heater therefor together with a pair 01 normally closed contacts for completing a circuit to said resistance heater and to said glow discharge device and operable by said resistance heater only upon continued operation of said glow discharge device for a predetermined period of time to cause opening oi. said contacts, a high resistance heater element normally connected in a shunt circuit with said glow discharge device and said actuating means and operable upon opening of said pair of contacts to heat said bimetallic element and maintain said contacts in an open position to interrupt the circuit to said glow discharge device to prevent operation of the same in a futile attempt to start said discharge lamp when the latter becomes defective, and said high resistance heater being automatically rendered mal operation upon replacement of the defective lamp.

4. In combination, a gaseous electric discharge lamp containing a thermionic cathode and a cooperating electrode, and a starting and operating circuit therefor comprising an inductance, means connecting one end of said thermionic cathode and said cooperating electrode across the terminals of a current source in series with said inductance, and a relay device connected across the opposite end of said thermionic cathode and to said electrode for initiating a discharg in said lamp and for locking-out said lamp in the event the same becomes defective comprising a glow discharge operable to initiate a discharge in said lamp, a thermal relay including a low resistance heater element in series with said glow discharge device and a pair of normally closed contacts and operable only upon continued operation of said glow discharge device for a predetermined period of time to heat said thermal relay and cause opening of said contacts with interruption oi the circuit to said glow discharge device, a high ohmic resistance heater normally connected in a shunt circuit with said glow discharge device and said low resistance heater and operable upon opening of said contacts to heat said thermal relay and maintain said contacts in an open position to interrupt the circuit to said glow discharge device to prevent operation of the same in a futile attempt to start said discharge lamp when the latter becomes defectiv and said high resistance heater being automatically rendered inoperative with attendant closure of said contacts and restoration of said relay device for normal operation upon replacement of the detective lamp.

5. In combination, a gaseous electric discharge lamp containing a thermionic cathode and a cooperating electrode, and a starting and operating circuit therefor comprising an inductance, means connecting one end of said thermionic cathode and said cooperating electrode across the terminals of a current source in series with said inductance, and a relay device connected across the opposite end of said thermionic cathode and to said electrode for causing the initiation of a discharge in said lamp and for locking-out said lamp in the event the same becomes defective comprising a glow switch provided with electrodes one 01' which is a bimetallic element adapted to be heated by the ensuing glow discharge upon the application of the voltage of said current source therebetween, said bimetallic electrode being operable to deflect into engagement with the other electrode of said glow switch to complete a series heating circuit for said thermionic cathode and to extinguish said glow discharge and operable upon cooling thereof to interrupt said series heating circuit and cause a high voltage surge from said inductance across the electrodes of said lamp with attendant initiation of a discharge therebetween, and a thermal relay comprising a heat-responsive member normally closing a pair of contacts and a resistance heater ele-' said glow switch and first mentioned resistance heater and operable upon opening of said contacts to heat said heat-responsive member and maintain said contacts in an open position to interrupt the circuit to said glow switch to prevent operation of the same in a futile attempt to start said discharge lamp when the latter becomes defective and said high resistance heater being automatically rendered inoperative with attendant closure of said contacts and restoration of said relay device for normal operation upon replacement of the defective lamp.

6. A relay unit for starting and operating a discharge lamp comprising a casing, a glow switch disposed in said casing provided with electrodes therein one of which is a bimetallic element and between which a glow discharg occurs upon the application of the potential of the source of supply for the discharge lamp, said bimetallic electrode being operable to deflect into engagement with the other electrode of said glow switch and cause the initiation of a discharge in said lamp, actuating means in said casing connected in series with saisl glow switch and having a pair of normally closed contacts for completing the circuit to said glow switch and to said actuating means, and said contacts being operable by said actuating means to open the circuit to said glow "switch and said actuating means upon the continued application of substantially the full potential of the source of supplyjor said discharge lamp to said glow switch for a predetermined period of time, means normally connected in a shunt circuit with said glow switch and said actuating means and operable upon opening of said contacts to maintain said contactslin an open position and to prevent continued operation of said glow switch in a futile attempt to initiate a discharge in said lamp when the latter becomes defective and said last mentioned means being automatically rendered inoperative with attendant closure of said contacts and restoration of said relay device for normal operation upon replacement of the defective lamp.

7. A relay unit for starting and operating a discharge lamp comprising a casing, a glow switch disposed in said casing provided with electrodes therein one of which is a bimetallic element and between which a glow discharge occurs upon the application of the potential of the source of supply for the discharge lamp, said bimetallic electrode being operable to deflect into engagement with the other electrode of said glow switch and cause the initiation of a discharge in said lamp, a low resistance heater element in said casing connected in series with said glow switch and having a pair of normally closed contacts for completing the circuit to said glow switch and to said low resistance heater element, and said contacts being operable by said low resistance heater element to open the circuit to said glow switch and said heater element upon the continued application of substantially the full potential of the source of supply for said discharge lamp to said glow switch for a predetermined period of time, a high resistance heater element normally connected in a shunt circuit with said glow switch and said low resistance heater element and operable upon opening of said contacts to maintain said contacts in an open position and to prevent continued operation of said glow switch in a futile attempt to initiate a discharge in said lamp when the latter becomes defective, and said high resistance heater being automatically rendered inoperative with attendant closure or said contacts and restoration of said relay device for normal operation upon replacement of the defective lamp.

8. A relay unit for starting and operating a discharge lamp comprising a casing, a glow switch disposed in said casing provided with electrodes therein one of which is a bimetallic element and between which a glow discharge occurs upon the application of the potential of the source of supply for the discharge lamp, said bimetallic electrode being operable to deflect into engagement with the other electrode of said glow switch and caus the initiation of a discharge in said lamp, a low resistance heater element and a bimetallic member in said casing connected in series with said glow switch and said bimetallic element being normally operable to maintain closure of a pair of contacts for completing the circuit to said glow switch and to said low resistance heater element, and said low resistance heater element being operable to heat said bimetallic element to open the contacts and interrupt the circuit to said. glow switch and said heater element upon the continued application of substantially the full potential of the source of supply for said discharge lamp to said glow switch for a predetermined period of time, a high resistance heater element normally connected in a shunt circuit with said glow switch and said low resistance heater element and operable upon opening of said contacts to heat said bimetallic element and maintain said contacts in an open position to prevent continued operation of said glow switch in a futile attempt to initiate a discharge in said lamp when the latter becomes detective, and said high resistance heater being automatically rendered inoperative with attendant closure of said contacts and restoration of said relay device for normal operation upon replacement of the defective lamp.

ROY M. SMITH. JOHN R. S'I'EEGB'I'RA.

Disclaimer 2,355,476.R0y M. Smith, Fairfield, and J 072m B. Steegstm, Bridgeport, Conn. FLUORESCENT LAMP STARTER. Patent dated Aug. 8, 1944. Disclaimer filed June H, 1951, by the assignee, The Bwyant E Zectm'o flompany.

Hereby enters this disclaimer to claims 6, 7, and 8 of said patent.

[Ofiicz'al Gazette July 10, 1951.]

Disclaimer 2,355,476.R0y M Smith, Fail-field, and J 075m B. Steegstm, Bridgeport, Conn. FLUORESCENT LAMP STARTER. Patent dated Aug. 8, 1944. Disclaimer filed June 14, 1951, by the assignee, The Bwycmt Elecmlo Company. Hereby enters this disclaimer to claims 6, 7 and 8 of said patent.

[Oflicz'al Gazette July 10, 1951.]