US3086141A

US3086141A - Starter and circuit for electric discharge device

Info

Publication number: US3086141A
Application number: US730720A
Authority: US
Inventors: Jacob H Rubenstein
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-04-24
Filing date: 1958-04-24
Publication date: 1963-04-16
Anticipated expiration: 1980-04-16

Description

Aprll 16, 1963 J; H. RUBENSTEIN 34 9 STARTER AND cmcun FOR ELECTRIC DISCHARGE DEVICE Filed April 24; 1958 I i 1 I l l l C I V5 g I 3 X i i 33 L J I 7 //MAGNETIZING L I FORCE F162 F1C5.l

.=////////////////////////= if; 45 x 4| INVENTOR. JACOB l-LRUBENSTEIN BYWIO-W AGENT United States Patent 3,086,141 STARTER AND CIRCUIT FOR ELECTRIC DISCHARGE DEVICE Jacob H. Rubenstein, 101 Shirley Road, Syracuse, N.Y. Filed Apr. 24, 1958, Ser. No. 730,720 12 Claims. (Cl. 315--100) This invention relates to an improved starter and starting circuit for :a gaseous electric discharge device having thermionic electrodes, such as a hot cathode type of fluorescent lamp, or the like, and more particularly to a starter which will positively ignite such a device the first time that it causes a starting voltage to be impressed across it. While the following description refers to a fluorescent lamp, it will be understood that it may be equally applicable to analogous electric discharge devices.

It is well known that the life of a fluorescent lamp is inversely proportional to the number of times that starting voltage is impressed across the lamp whether the lamp actually ignites or not. In practically all the starters of the prior'art ignition of the lamp did not occur until starting voltage had been impressed across the lamp a few times, this procedure materially reducing lamp life and causing objectionable blinking during this starting process. In addition to the foregoing objectionable blinking, starters of the prior art permitted a fluorescent tube to blink objectionably after it wore out. It is with the overcoming of the foregoing shortcomings of the fluorescent lamp starters of the prior art that this invention is concerned.

It is therefore the principal object of this invention to provide a fluorescent lamp starter which will prolong the life of :a fluorescent lamp by positively igniting the lamp upon the initial impressing of starting voltage across it.

A further object of this invention is to provide an im proved starter which prevents blinking of a fluorescent lamp not only upon starting but also when the lamp is worn out, this in turn preventing a reduction in the life of the starter associated therewith and eliminating the annoyance caused by the blinking of a fluorescent lamp.

Another object of this invention is to provide a starter which will operate over a wide voltage range so that it will positively ignite a fluorescent lamp even when the line voltage varies abnormally. Other objects and attendant advantages of the present invention will readily be perceived hereafter.

The starter of the present invention achieves the foregoing objects by positively initiating the starting voltage close to the peak value of the current cycle, thereby caus ing a maximum voltage kick. to be impressed across the fluorescent lamp. This occurs after a predetermined lamp-filament preheat time has elapsed. This procedure causes the fluorescent lamp to positively ignite upon the initial impressing of starting voltage across it.

The present invention relates to a starter and starting circuit for positively igniting a fluorescent lamp .upon the initial application of starting voltage across the electrodes thereof comprising a source of electric current, a ballast reactor coupled to said lamp, means for preheating said electrodes for 13. predetermined period, and means for causing said ballast reactor to provide a starting voltage across said lamp after said preheat period has elapsed to positively ignite said lamp the first time starting voltage is impressed across said electrodes. The obtaining of the starting voltage which will positively ignite the lamp is due to the use of a magnetic relay having a core and armature of magnetic material of low coercive force or low retentivity. This material causes the starting voltage to be impressed at substantially the peak value of the current cycle so that the voltage produced by the ballast reactor is at a maximum. The present invention will be more fully understood when the following portions of the specification are read in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a schematic wiring diagram of a fluorescent tube circuit including the starter of the present invention, the portions shown in phantom deepicting the positions of starter elements after the initial impressing of starting voltage across the fluorescent lamp;

FIGURE 2 depicts a hysteresis loop of the low coercive force core material of the relay used in the starter, and, in broken lines, the hysteresis loop for conventional magnetic material; and

FIGURES 3 and 4 depict the actual construction of my improved starter, with certain parts omitted in the interest of clarity, FIGURE 4 being a view taken from the right of FIGURE 3.

Reference is now made to FIGURE 1 which shows a fluorescent lamp 10 having electrodes 11 and 12, which may consist of any conventional thermionic material. One side of electrode 11 is coupled through a conventional ballast reactor 13 to line L and one side of electrode 12 is coupled to line L through power switch 14.

The improved starter 15 of the present invention is coupled across the other sides of electrodes 11 and 12 by means of conductors 16 and 17, respectively. Starter 15 is preferably enclosed in a conventional starter case 39 (FIGURE 3) so that it may be interchanged with conventional starters now in use as the latter wear out. Coupled across leads 16 and 17 are a relay 18 having a core 19 of low magnetic retentive force (low coercive force) material and a current limiting resistor 20. Relay winding 21 and resistor 20 are coupled in series by conductor 22.

Coupled across leads 16 and 17 by means of

leads

23 and 24, respectively, is the preheating circuit for the filaments of lamp 10. During the preheat time which immediately follows the closing of switch 14, current flow is from L through switch 14, filament 12, lead 17, lead 24, lead 25, low coercive force relay armature 26, contact point 27 on the relay armature, contact point 28 (which is mounted on bimetallic arm 29), resistance heating coil 30, lead 23, lead 16, filament 11, land ballast reactor 13 to complete the circuit to L As is well known, the flow of current-through the filaments 11 and 12 causes them to heat up.

The parameters of the entire starter circuit are such that no appreciable current will flow through relay coil 18 during the preheat time because the above-described preheat circuit serves as a shunt.

The passage of current through resistance heater 30 will cause bimetallic arm 29 to be heated. The characteristics of bimetallic arm 29 and heater 30 may be chosen to give any length of preheat time required for any particular lamp. As arm 29 heats up, it will tend to deflect upwardly, thus tending to separate

contacts

27 and 28. When the desired preheat time has elapsed, the point is reached where

contacts

27 and 28 will start to separate and the shunting circuit across relay coil 21 will terminate because the spreading apart of contact points or

terminals

27 and 28 will in effect initially provide a, high resistance air gap, thus starting to overcome the shunting characteristic of the preheat circuit. As

contacts

27 and 28 start spreading apart because of the upward movement of bimetallic arm 29, higher current will start flowing through relay coil 21. Substantially at the instant when the current cycle reaches its peak value through coil 21, suflicient magnetization will be induced in low-coercive-force core 19 to positively pull down armature 26 (which is also made of low retentive force magnetic material) to its dotted line position, thus opening the contact points at substantially the peak value of the current cycle.

I believe the reason that

contact points

27 and 28 will open very close to the peak of the current cycle is because the high permeability-low retentivity material, which is used for the core and armature of the A.C. relay, has the property of having its induced magnetic flux closely follow the phase and wave form of the magnetizing force (which is proportional to the current through the relay coil). Furthermore, -for low values of magnetizing force, such as used in the relay of the present fluorescent lamp starter, the magnetic flux is proportional to the magnetizing force. Also, due to the low retentivity of the material in the core, there will be -a well defined magnetic peak pull on the armature of the relay. The foregoing characteristics will readily be appreciated from FIGURE 2 wherein curve 33 depicts the hysteresis loop of the low retentivity material which I utilize whereas curve 34 represents the hysteresis loop of a conventional laminated core material.

Armature biasing spring 42 is adjusted so that the armature downward movement responds only to the peak magnetic pull, and, as it has been pointed out above, this peak magnetic value occurs substantially simultaneously, in time, with the peak of the current cycle. Therefore, the

contact points

27 and 23 open substantially at the peak of the current cycle.

When the preheating circuit is broken in the above described manner so that it no longer provides a shunt across electrodes 11 and 12, the stored magnetic energy in ballast reactor 13 will produce an inductive kick (or starting voltage) across electrodes 11 and 12 to positively ignite the lamp 10. This positive ignition is due to the high value of the transient voltages set upacross the lamp when the current is interrupted at substantially peak value, in the above-described manner. Insofar as pertinent, the peak value of the current cycle is any value sufficient to cause ballast reactor 13 to produce an inductive kick which will cause positive ignition, this value usually being where the current is at least approximately 90% of its maximum value.

Once the lamp 10 is positively ignited in the foregoing manner, current will continue to flow across leads 16 and 17 through relay coil 21, lead 22, and current limiting resistor 20. This maintains relay 18 in an energized condition and keeps armature 26 in its dotted-line position so that

contact points

27 and 28 remain separated. This separation prevents blinking of a worn out lamp, this blinking ordinarily occurring with a conventional starter (which does not have this feature) as it attempts to ignite a worn out lamp which is incapable of being fully ignited.

Capacitor 31 is coupled between lead 24 and one end of bimetallic arm 29. This capacitor has a high capacitative reactance so that only a minute amount of current will flow through arm 29 and resistance heater 30 when the relay 18 is energized. Since this minute current is much lower than that previously flowing through resistance heater 30, the latter will cool to normal ambient temperature and thus assume its starting position so that when switch 14 is opened, armature 26 (which is spring biased upwardly) will assume its solid line position to place

contacts

27 and 28 in engagement so that the starter components immediately assume the necessary position for a subsequent starting operation.

A low coercive force material which I have used successfully is known by the term Allegheny Mumetal and is a commercial product of Allegheny Ludlum Steel Corporation. The typical chemical composition of this material is 77.2% nickel, 4.8% copper, 1.5% chromium and 14.9% iron.

In FIGURES 3 and 4 is shown a preferred construction of my improved starter illustrating the preferred orientation of parts, the wiring connections of FIGURE 1 having been omitted for the sake of clarity. The same numerals on these figures which appear in FIGURE 1 depict the same elements described above relative to FIGURE 1, and it is believed that a detailed repetition of these numerals is superfluous. In addition to the components set forth in FIGURE 1, FIGURES 3 and 4 disclose a circular dielectric disc or base 36 having

terminals

37 and 38 mounted thereon which are adapted to be received in a mating starter socket (not shown). Mounted on disc 36 is a cylindrical shell or housing 39 which, in combination with disc 36, encloses the starter. The relay core 19 is mounted on an L-shaped bracket 40, and positioned in the space below the horizontal arm of the bracket are capacitor 31 and resistor 21}. An inverted U-shaped yoke 41 has its depending legs fastened to relay coil 21 in any suitable manner. Extending upwardly from the horizontal leg of bracket 40 is a piece of spring metal 42 (such as piano wire) to which is fastened armature 26 which is made of the low coercive force metal described above. Attached to yoke 41 by means of support '43 is bimetallic arm 29. Support 43 has an end portion 44 to limit the upward movement of armature 26. The free end of bimetallic arm 29 has fastened thereto an inverted U-shaped bracket 45, the depending legs of which straddle the armature 26 to prevent the latter from undesirable lateral displacement. Upon downward movement of bimetallic arm 29, the ends of the depending legs of U-shaped bracket 45 contact relay coil 18 to limit downward movement of arm 29 under extremely cold ambient conditions.

It can be seen from the foregoing description that a fluorescent lamp starter has been disclosed which positively ignites a fluorescent lamp upon the initial application of starting voltage across the terminals thereof, thus materially prolonging the life of the lamp and eliminating objectionable blinking during starting.

It must be appreciated, however, that the positive starting of the lamp Will occur only while the lamp is within its normal life span, i.e., before it becomes worn out. When the lamp is bad, ignition will not occur, thus indicating that the lamp should be replaced. However, since armature 26 remains in its dotted line position after a starting attempt has been completed, there will be no objectionable blinking of the worn-out lamp because of the elimination of the continued starting attempts which cause the blinking of the worn-out lamp.

As noted above, the starter of the present invention also positively ignites a fluorescent lamp at low values of line voltage because it always causes the ballast reactor to produce a maximum inductive kick inasmuch as the latter is produced at substantially the peak of the current cycle.

While I have described a preferred embodiment of my invention, I desire it to be understood that it is not limited thereto but may otherwise be embodied within the scope of the following claims:

I claim:

1. A starting circuit for positively starting a gaseous electric discharge device a predetermined time after the circuit is energized comprising a source of electric current, switch means for coupling said device to said source of current, a ballast reactor coupled to said device, a time delay circuit means for permitting preheating current to flow through the electrodes of said device after the closing of said switch means, and means for substantially simultaneously terminating said preheating and causing said ballast reactor to always produce its initial voltage discharge across the electrodes of said device at substantially the peak value of the current cycle to positively start said device upon the initial application of voltage across said electrodes by said ballast reactor.

2. A starting circuit for a gaseous electric discharge device having electrodes adapted to be energized from a source of electric current by the use of a switch for coupling said electrodes across said source of current, said starting circuit including a ballast reactor coupled to said device, a time delay circuit adapted to permit preheating current to flow through said electrodes for a predetermined time after said switch is actuated, and circuit means shunted by said time delay circuit during said predetermined time for positively causing said predetermined preheating time to terminate and causing said ballast reactor to positively produce its initial voltage discharge across said electrodes at substantially the peak value of a current cycle to thereby positively start said device upon the initial application of ballast reactor produced voltage across said electrodes.

3. A starter for a circuit having a ballast reactor and a gaseous electric discharge device having a plurality of electrodes including at least one thermionic electrode therein comprising preheat means for permitting current to flow through said thenmionic electrode for a preheating period, and means for causing said ballast reactor to always impress its first voltage discharge across the electrodes of said discharge device after the termination of said preheat period and at substantially the peak value of a current cycle whereby said electric discharge device will always start the first time that said ballast reactor impresses a voltage across said device.

4. A starter for an electric discharge device having at least one thermionic electrode in a circuit with a ballast reactor comprising means for providing a single preheating period for said electrode, and means for causing said ballast reactor to impress a starting voltage across said device only once at substantially the peak of a current .cycle after said preheating period to thereby either cause starting of said discharge device with a single ballastreactor produced voltage if it is capable of functioning or prevent blinking of said discharge device if it is incapable of functioning by preventing additional starting attempts.

5. A starter for an electric discharge device having at least one thermionic electrode, said starter adapted to be used in a circuit with a ballast reactor and a first switch for coupling said device to a source of electric current, said starter comprising a second switch having first and second contacts, a thermostatic element adapted to move said first contact, a relay having a winding and a core and an armature, said armature adapted to move said second contact, heating means associated with said thermostatic element, first circuit means operative after the closing of said first switch for permitting current to [flow through said ballast reactor and thermionic electrode and second switch and heating means to thereby preheat said thermionic electrode, said first and second contacts tending to separate as a result of the efiect of the heat produced by said heating means causing said thermostatic element to deflect, and second circuit means coupling said relay Winding to said source of current, said second circuit means permitting sufiicient current to flow through said relay winding as said first and second contacts tend to separate to cause said armature to deflect and said second switch to positively open at substantially the peak value of a current cycle to thereby terminate preheating of said electrode and disrupt the flow of current through said ballast reactor at substantially the peak value of said current cycle whereby the voltage discharge produced by said ballast reactor at said peak value of said current cycle will start said electric discharge device.

6. In combination in an electric circuit having a source of alternating current, a device relative to which it is critical that a switching action be performed at a predetermined portion of a current cycle, first selectively actuable switch means for coupling said device to said source of current, circuit means including second switch means for permitting current to flow to said device after the actuation of said first switch means, said second switch means including a relay armature associated therewith, and electromagnetic relay means including said armature and responsive to a variation in the flow of current through said electromagnetic relay means for eifecting a deflection of said armature and thereby actuating said second switch means at said predetermined portion of said current cycle.

7. A starter for an electric discharge device having at least one thermionic electrode for use in combination with a circuit having a ballast reactor and a source of alternating electric current and switch means for coupling said electric discharge device to said source of current, said starter comprising circuit means for permitting preheating current to flow through said thermionic electrode after the closing of said switch means, and means for causing said ballast reactor to always impress a starting voltage across said device only once and at substantially the peak of a current cycle after said preheating current has flowed through said thermionic electrode for a predetermined period after the closing of said switch means to thereby either cause starting of said discharge device while subjecting it solely to a single ballast reactor produced voltage discharge if it is capable of functioning, without causing blinking of said discharge device due to additional starting attempts producing additional ballast reactor produced voltage discharges if it is incapable of functioning, and means for resetting said circuit means in response to the opening of said switch means to thereby prepare said circuit means for a repetition of the flow of said preheating current through said thermionic electrode and the single impressing of said starting voltage in response to a subsequent closing of said switch means.

8. A starter for an electric discharge device comprising a base, a housing mounted on said base, a plurality of terminals adapted to be coupled to a source of current, a relay mounted within said housing, said relay having a core and a winding and an armature, first circuit means coupling said winding across said terminals, a switch having a pair of contacts, one of said contacts being mounted for movement by said armature, second circuit means coupling said switch across said winding, means for causing said first and second contacts to start separating as a result of the passage of current through said second circuit means, said first circuit means permitting sufiicient current to flow through said winding as said contacts tend to separate to cause said armature to be deflected, and means operatively associated with said relay for causing said switch to always produce its initial opening at substantially the peak value of a current cycle.

9. A starter for an electric discharge device having a pair of electrodes including at least one thermionic electrode, said starter adapted to be used in a circuit with a ballast reactor and a first switch for coupling said device to a source oi? electric current, said starter comprising first circuit means including a second switch having first and second contacts, a thermostatic element including heating means adapted to move said first contact, a relay having a winding and a core and an armature, said first circuit means being coupled across said electrodes and operative after the closing of said first switch for permitting current to fiow through said ballast reactor and thermionic electrode and second switch and heating means to thereby permit current flow to preheat said thermionic electrode, said first and second contacts tending to separate as a result of the effect of heat produced by said heating means causing said thermostatic element to deflect, and second circuit means coupling said relay winding across said second switch, said second circuit means permitting increased current to flow through said relay winding as said first and second contacts tend to separate, and said relay including means for causing said armature to be deflected and said second switch to positively open at substantially the peak value of a current cycle to thereby terminate preheating of said electrode and disrupt the flow of current through said ballast reactor at substantially the peak value of said current cycle whereby the initial voltage discharge produced by said ballast reactor occurs at said peak value of said current cycle to thereby start said electric discharge device upon the initial impressing of ballast reactor produced voltage across said electrodes.

10. A starter as set forth in claim 9 wherein said means included in said relay comprise a low coercive force material.

11. A starting circuit as set forth in claim 2 wherein said time delay circuit means is connected across said electrodes and includes a switch actuated by the armature of a relay, said armature being of low coercive force material.

.12. A starting circuit as set forth in claim 11 wherein said relay includes a core of low coercive force material for deflecting said armature to break said time delay circuit means, said core having a winding connected across said electrodes.

References Cited in the file of this patent UNITED STATES PATENTS 2,155,816 Babb Apr. 25, 1939 2,181,294 Biggs Nov. 28, 1939 2,341,520 Babb Feb. 15, 1944 2,378,222 Inman June 12, 1945 FOREIGN PATENTS 530,098 Great Britain Dec. 4, 1941)