AU628421B2 - Device for igniting gas-discharge lamps - Google Patents

Description

OPI DATE 12/06/90 APPLN. I D 4146 89 IP1cJ ATEw L/U//JU MLI NUMBER PCI/CN89 /U(

INTERNATIONALE

INTERNATIONALE .u1ivjiIt~L 0209J (21) Internationales Aktenzeichen: PCT/CH89/00209 (81) Bestimmungsstasiten: AT (europaiisches Patent), AU, BE (europiisches Patent), BG, BR, CH (europ~isches Pa- (22) Infernationales Anmeldedatuni: tent), DE (europaiisches Patent), DK, ES (europqisches 24. November 1989 (24.11.89) Patent), Fl, FR (europflisches Patent), GB (europ~iisches Patent), HU, IT (europaiisches Patent), JP, KR, LK, LU (europ~iisches Patent), NL (europdiisches Patent), NO, PrioritAtsdaten: RO, SE (europ~iisches Patent), SU, US.

4331/88-5 24. November 1988 (24.11.88) CH Verdffentlicht (71) Anmielder (fir alle Bestimmnungsstaaten ausser US): SKYLI- Mit internationalern Reclzerclienbericht.

NE HOLDING AG [CH/CH]; Kranichweg 19, CH- l'or Ablauf der flr 4nderungen der Ansprfiche zygelasse- 3074 Muri b. Bern nen Frist. Verbffentlichung ivird wiederliolt falls 4nderun- (72) Erfinder; und eeitfen Erfinder/Anmelder (nurftr US) MOESSLI, Daniel [CH/ CH]; Tannholz 39, CH-3214 Ulmiz (74)Anwalt: GASSER, Franqois, Laupenstrasse S P.O. ti Box 6262, CH-3001 Bern 684211 (54)Title: DEVICE FOR IGNITING GAS-DISCHARGE LAMPS (54) Bezeichnung: ANSTEUERUNG FOR GASENTLADUNGSLAM PEN (57) Abstract C.5 To overcome the drawback of temperature-related fluctuations in the lumi- RC.

nous efficiency of gas-discharge lamps, in particular compact fluorescent lamps, a temperature-compensating element which controls the lamp current in funic- TI R 2 R I: tion of temperature is incorporated in the ignition device. This type of tempera- I~ I ture-compenisating element advantageously consists of a current-limiting reac- -1 T tor in the form of a coil with a central core The core (10) is acted on by a 1 Y.4 sprieg (11) and a bimetallic spring (12) in such a waythat if' depth of penetration Dr, z ROIAC~I Ii into the coil is a function of temperature, The resultant variation in the induc- f 3 tion of the current-limiting reactor cav'ses the lamp current to vary in funcdiun F11D of temperature in such a way that the gas-ischarge lamp is or limally operated in- C dependently of temperature. This rrcsults in constant maximu' luminous efficien- (57) Zusamnmenfassung _CqI MS1 Umn den Nachteil der' temnperaturbedingt unterschiedlichen Lichtausbeute L 4 bei Gasentladungslampen, insbesondere Kompaktieuchtstoffiampen, zu elirninie- ren, wird in die Ansteuerung emn Temperaturkompensationselement int-.griert, dlas dazu dlient, den Lampenstrom temperaturabbanrgig zu steuern. Emn solches Temperatu rkomnpens ationselement kann vorteilhafterweise aus einer Strombegrenzungsdrossel in Form einer Spule mit zentralem Kern (10) bestehen, bei de der Kern (10) durch eine Feder (11) und eine Bimetallfeder (12) derail beaufschlagt ist, dlass seine Eindringtiefe in die Spule ter ,peratu rabh fingig ist. Durch die sich daraus ergebendle Verfladerung der Induktion der Strombegrenzungsdrossel wird der Lampenstrom temperaturabblingig verfindert, derart, dass die Gasentladungslampe temperaturunabblingig stets optimal betrieben wird, was zu einer immer gleichen maximalen Lichtausbeute fiihrt und/oder einen der Umgebungstemperatur angepassten maximalen Lampenstrom erm~glicht.

This invention concerns a control device for gas discharge lamps.

With gas discharge lamps, usually known as fluorescent light tubes, and especially with compact fluorescent lights, as available today as power economising lights with standard screw socket, the luminous efficiency at a specified current is influenced by the operating temperature of the lamp and, for the compact fluorescent lights, on the electronics accommodated in the screw socket base. Should the surrounding temperature vary from a nominal temperature value, for example the temperature drops for lamps installed outside and the temperature rises for S. lamps installed inside, then this results in a reduction in luminous efficiency and a decrease in luminous flux. Since the S, heat loss of compact fluorescent lights is limited by their small 15 size, a maximum power supply for the light must be chosen to allow for any worse-case conditions which lie below the maximum load capacity of the compact fluorescent light.

c *o This invention aims to provide a control device for gas discharge lamps, such as compact fluorescent lights with an interposed auxiliary mechanism incorporated in the light socket, which will alleviate to a large extent the abovementioned t disadvantages. In a further aspect this invention aims to provide a control device for gas discharge lamps whic-h will supply a temperature dependent variable current to the light in such a manner that a high luminous efficiency is achieved over a wide range of temperatures. A nearly constant luminous efficiency of the gas discharge lamp may be achieved, even when i the temperature varies.

With the foregoing and other objects in view, this invention resides broadly in an ene3rgizing system for a gas discharge lamp, comprising an electronic circuit including: a full-wave bridge rectifier connectable to a source of power; 0 o 0 9 09* rc 0.0. 15 oa 00« 20 4 4 ti I Ii 1 t a smoothing reactor connected to an output of said rectifier; an oscillating starting circuit connected to said smoothing reactor whereby connection of said rectifier to said source of power causes activation of said starting circuit; a high frequency resonant/oscillating circuit connected to said starting circuit; a lamp receiving base serially connected to said high frequency resonant/oscillating circuit; and a temperature compensating element within said base and connected into said electronic circuit, said temperature compensating element comprising: a coil connected into said electronic circuit; a ferrite core slidably mounted within an opening through said coil, said core having a first end and a second end; a first spring engaging said first end and biasing said core for movement in a first direction; a second spring engaging said second end and biasing said core for movement in a second direction opposite said 2b above, and FIG. .6 shows the lamp socket base according to FIG. 5 in partial cross-section.

FIG. 1 shows, in the form of a circuit diagram, the control device for a gas discharge lamp 10 This includes an electronic circuit 2, as used in auxiliary devices and which, in the main, consists of a HF-generator followed by a temperature compensation mechanism 3. As is usual with gas discharge lamps, in order to start the gas discharge, a condenser 4 is connected in parallel with the fluorescent tube.

a (i 4 1

I

0 0 ft« 1I ii W090/05992 PCT/CH89/00209 Figure 2. illustrates a preferred design of the electronic circuit 2 in which the supply voltage, for example 220 Volt at 50-60 Hz, is connected to terminal contacts 5 and 6.

A fuse Si prevents any damage from high currents, especially from short circuiting, as a result of faults in circuit 2.

The Diodes D1, D2, D3 and D4 as w4ll as a first and second condenser C01 and 02 act as rectifiers, to which, at the positive end, are connected a choke DR and a third condenser 03 for smoothing purposes. A starter circuit, consisting of a first resistor R1, a fourth condensor 04 as well as a fifth diode D5 and a Diac DIA ensure that when the supply power is switched on at terminals 5 and 6, a high frequency oscillatory (resonant) circuit is activated. This circuit consists of a first winding TR1A of a currert transducer with a base resistor R2 following a first transistor T1 and an emmission resistor R3 on the one side and a second winding TR1B of a transducer with base resistor R4 following a second transistor T2 with emmission resistor R5 on the other side. Two further diodes D6 and D7 as well as a RC-link, consisting of a sixth resistor R6 and a sixth condenser 06, serve to stabilise the frequency of the high frequency oscillatory circuit. The gas discharge lamp 1, here shown in the form of a compact flourescent light, is connected following the high frequency oscillatory circuit by means of a fifth condenser C5 and a third winding TRiC of the transducer, whereby the temperature compensation J mechanism 3, here in a form of a voltage choking device L with temperature driven induction, is interposed in parallel to poles 7 and 8 for the gas discharge tube and at the location of condenser 4.

A preferred design of a current limiting choke L with a temperature dependent induction (impedance), which acts as temperature compensation mechanism 3 is explained in Figures 3 and 4. As can be seen, it involves having a coil 9 with a W090/05992 4 PCT/CH89/00209 sliding central core 10 preferably made of ferrite material.

For this core, there is on one side, along its axis, a helical spring 11, and on the other side, acting in the opposite direction, there is a temperature sensitive leaf spring 12, preferably made of a bi-metallic material. The ferrite core 10, depending on the ambient temperature, is pushed to some extent into the coil 9. The adjustment of the tension of the two opposing springs 11 and 12 is preferably done so that the current limiting choke L has a specified impedance relative to a specified temperature, which also corresponds to the calculated value which the current limiting choke L must have so that the gas discharge lamp receives the exact amount of current to allow it to deliver the maximum luminous efficiency under the operating conditions.

When the surrounding temperature lies below the specified temperature value, the ferrite core 10 is pushed further out of coil 9 by the helical spring 11. This causes the impedance of the current limiting choke L to decrease so that the current to the lamp is increased. The temperature related loss of luminous efficiorcy is therefore compensated by the increased current supplied to the lamp.

If the surrounding temperature is highrr that the specified temperature value, the ferrite core 10 will by pushed futher into the ccil 9 by the bi-metallic leaf-spring 12. This causes the induction of the current limiting choke L to increase and the current for the lamp decreases. In this manner the excessive luminous efficiency of the gas discharge lamp 1, due to increased temperature, is counteracted. As may be seen from Figure 3. and the coil 9 with its ferrite core 19 and the two springs 11 and 12 are accommodated in a housing 13.

W090/05992 5 PCT/CH89/00209 As may be seen from Figure 5. and the housing 13 could advantageously constitute the lamp's socket, into which the two ends of the gas discharge lamp 1 with its poles 7 and 8 are inserted. The coil 9 with its ferrite core 10 and springs 11 and 12 are embedded in the lower part of the socket housing. This arrangement is particular advantageous because the temperature compensation mechanism 3 is located at exactly the spot at which there is the greatest temperature difference between the warm and the cold gas discharge lamp 1. The temperature compensation mechanism can therefore act to control the power supply to the lamp without any delay due to a long warm-up or cooling phase of the lamp so that no variations of luminous intensisty can be detected by the human eye as a result of either a colder or warmer environment for the lamp.

The professional person realises, that the control device of this invention For gas discharge lamps, especially compact flourescent lights, not only makes possible the physiological advantages of a temperature independent lighting source, but also allows the optimal operation of gas discharge lamps independent of temperature.

It is self evident that the application of the control device of this invention is not limited to compact flourescent ligts. It may be used, with advantage, for practically every type of gas discharge lamp. The temperature compensation mechanism need not necessarily be housed in the lamp's socket base, but could also be placed at other temperature sensitive locations.

The professional person recognises that, in 'lace of the temperature regulated current limiting choke L, a temperature dependent element could, for example, be used, and be incorporated into electronic circuit 2 to regulate te frequency of the high frequency oscillatory circuit.

RL~a~ -*u~lt I I W090/05992 6 PCT/CH89/00209 This in turn would produce the desired effect on the supply current for the lamp.

It is self evident that the control device of this invention could be provided with electronic circuitry 2, which differs from the circuits described here. Furthermore, it is not absolutely necessary to physically separate the electronic circuit 2 from the temperature compensation mechanism 3, as suggested by the diagram. It is also suggested, that the current limiting choke L need not be constructed in the manner described in order to produce the desired result.

All these structural and circuit modifications of the control device of this invention certainly lie within the scope of what technically competent persons could produce, based on the invention, without using their own inventive activity. Therefore, it is not necessary to provide further details here.

Claims (7)

1. An energizing system for a gas discharge lamp, comprising an electronic circuit includingt a full-wave bridge rectifier connectable to a source of power; a smoothing reactor connected to an output of said rectifier; an oscillating starting cicuit connected to said smoothing reactor whereby connection of said rectifier to said source of power causes activation of said starting circuit; i a high frequency resonant/oscillating circuit connected I to said starting circuit; a lamp receiving base serially connected to said high frequency rasonant/oscillating circuit; and a temperature compensating element within said base and connected into said electronic circuit, said temperature compensating element comprising: a coil connected into said electronic circuit; a ferrite core slidably mounted within an opening through said coil, said core having a first end and a second end; a first spring engaging said first end and biasing said core for movement in a first direction; a second spring engaging said second end and biasing said core for movement in a second direction opposite said first fit 8 direction; said second spring being movable in a temperature dependent fashion whereby increases in temperature cause said second spring to move said core in said second direction to increase the inkoaotion of said coil and reductions in temperature cause reduction in biasing force of said second spring allowing said first spring to move said core in said first direction to reduce the induction of said coil, whereby lamp brightness is maintained substantially constant throughout a wide ambient temperature range.

2. An energizing system as claimed in claim 1, wherein said electronic circuit further includes a frequency stabilization section connected to said high frequency o resonant/oscillating circuit, o* 6

3. An energizing system as claimed in claim 1 or claim 2, wherein said circuit includes a current transmitter including first and second windings incorporated into 9 said high frequency resonant/oscillating circuit and a third winding incorporated into said frequency stabilization circuit.

4. An energizing system as claimed in any one of the preceding claims, further including a capacitor serially connected between said base and said high frequency resonant/oscillating circuit. .An energizing system as claimed in any one of the preceding claims, wherein said second spring comprises a bi-metallic spring. 6, An electronic circuit for starting and controlling illumination of a gas discharge lamp mounted in a base, the improvement comprising a temperature compensating element connected into said electronic circuit and comprising a coil connected into said electronic circuit; a ferrite core slidably mounted within an opening through S. said coil, said core having a first end and a second end; a first spring engaging said first end and biasing said core for movement in a first end and biasing said core for I. movement in a first direction; a second spring engaging said second end and biasing said core for movement in a second direction opposite said fir~t direction; said second spring being movable in a temperature dependent fashion whereby increases in temperature cause said second spring to move said core in said second direction to increase the induction of said coil and reductions in temperature cause reduction in biasing force of said second spring allowing said first spring to move said core in said a lamp receiving base serially connected to said high frequency resonant/oscillating circuit and a temperature compensating element within said base and connected into said electronic circuit, said temperature /2 first direction to reduce the induction of said coil, whereby lamp brightness is maintained substantially constant throughout a wide ambient temperature range.

7. An electronic circuit as claimed in claim 6, wherein said coil is located in said base.

8. An electronic circuit as claimed in claim 6 or claim 7, wherein said second spring comprises a bi-metallic spring.

9. A fluorescent light having a lamp socket base and a temperature dependent inductance in the socket and adapted to co-operate with an electronic circuit as "claimed in any one of the preceding claims whereby the current supplied to said fluorescent light is temperature t dependant. A fluorescent light lamp socket base as substantially hereinbefore described with reference to the accompanying drawings. DATED THIS Third DAY OF June ,1992 SKYLINE HOLDINGS AG PIZZEY COMPANY PATENT ATTORNEYS