Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
  • H05B41/02—Details
  • H05B41/04—Starting switches
  • H05B41/042—Starting switches using semiconductor devices
  • H05B41/044—Starting switches using semiconductor devices for lamp provided with pre-heating electrodes
  • H05B41/046—Starting switches using semiconductor devices for lamp provided with pre-heating electrodes using controlled semiconductor devices

Definitions

• the present invention relates generally to a starting device for discharge lamps connecting by two access terminals to the electrodes of a discharge lamp, the device being supplied by the cyclic voltage of the network through a reactive ballast and the electrodes of said lamp.
• the most widely used starting device comprises a glow discharge switch connected in parallel to the discharge tube and in series with the filaments of this tube, the alternative source, a commissioning switch and a- self stabilizer or ballast.
• the device has the drawback that the tube does not light up until after a certain number of awkward ignition attempts which affect the user and alter the life of the tube.
• Another drawback lies in the fact that the proper functioning of this device strongly depends on the temperature conditions, fluctuations in the network voltage as well as the aging of the tube and of the glow discharge switch.
• More sophisticated devices preventing flashing on ignition, exist but they generally include a mechanical element. This has the disadvantage of a lifetime linked to the number of requests.
• Static devices often include inductors and / or more than two access terminals. In addition, they prove unable to properly ignite the new generation fluorescent tubes and more particularly the tubes.
• the present invention aims to provide a new electronic starting device for discharge lamps not having the aforementioned drawbacks and advantageously designed in such a way
• the aim of the invention is achieved by providing a starting device for discharge lamps which is connected by two access terminals to the electrodes of a discharge lamp, this device being supplied by the cyclic voltage of the network through a reactive ballast and the electrodes of said lamp, characterized in that it comprises static means performing the functions: adequate preheating of the lamp for a time dependent on fluctuations in »the voltage of the supply network and generation of a pulse of voltage adaptable to the type of lamp to be lit, the voltage pulse occurring only after the preheating time of the lamp.
• This device can also advantageously include a fully static protection which ensures that it is automatically switched off in the event of the tube not being ignited after a few ignition attempts. This can happen when the tube is at the end of its life. Adopting an adequate preheating time that adapts "naturally" to fluctuations in the supply network voltage, followed by a pulse occurring after this preheating time, largely eliminates the reduction in useful life of the tube which depends, among other things, on the number of ignition stresses.
• FIG. 1 shows a device for igniting discharge lamps belonging to the state of the art
• Figure 2 - shows an electronic diagram being the basic cir ⁇ cooked of the present invention
• FIG. 3 shows the circuit of FIG. 2 where the configuration of the circuit has been changed in order to be able to use higher ignition voltages
• FIG. 4 gives the appearance of the voltage across the terminals of the device of the invention and of the current passing through it
• FIG. 5 shows the circuit of FIG. 3 in which two additional terminals have been removed
• Figure 6 i shows a way of connecting two tubes
• FIG. 7 shows another embodiment of the invention in which another type of semiconductor switch is used
• FIG. 8 shows the circuit of FIG. 7 modified to obtain an advantageous control of the semiconductor switches;
• FIG. 9 shows another embodiment of the invention in which a third type of semiconductor switch is used;
• FIG. 10 shows the circuit of FIG. 9 modified to avoid re-priming of the preheating switch during the release of the pulse;
• Figure 11 shows the circuit of Figure 10 modified to be able to use higher starting voltages;
• FIG. 12 shows an embodiment of a circuit part making it possible to make even higher ignition voltages usable;
• Figures 13 and 14 show other means for simultaneously lighting two tubes;
• Figure 15 shows another arrangement of the device of the invention in the circuit including the tube;
• Figure 16 shows another embodiment of the invention allowing the connection according to Figure 15;
• FIG. 17 shows another embodiment allowing the connection according to Figure 15; and FIG. 18 shows the shapes of the network voltages and at the terminals of the tube as well as the shape of the preheating current for the circuits of FIGS. 16 and 17. Identical references are used for identical or similar elements.
• the device of the state of the art represented in FIG. 1, comprises a lumi ⁇ nescent discharge switch 2, connected in parallel to the fluorescent discharge tube 1 and in series with the filaments l 'of this tube, the source alternative 4, the start-up switch 3 and a stabilizing choke or ballast 5.
• the life of the tube 1 depends on its use and on the number of ignitions, itself depending on the aging of the elements 1 and 2.
• the device of the invention is subdivided into three functional parts; a) the elements 22 to 29 ensuring a preheating of the tube for a period depending on fluctuations in the voltage of the supply network, comprising at least one semiconductor switch 29 of the thyristor or triac type and a control circuit 23 to 28 rendered inactive during the rise of the priming pulse.
• the elements 7 to 21, forming a "forced switching" circuit, transferring the preheating current towards it at a determined time and delivering after this transfer, a voltage pulse initiating the tube, this part of the circuit comprising at least one semiconductor switch whose ignition, controlled by a circuit 7, 8, 9, 10, 11, 12, 13 in which the voltage rises in stages, depends, among other things, on the voltage drop across a resistor 16 while the preheating current is flowing and also comprising a means for producing a high voltage 17 to 21, c) a part guaranteeing a fully static protection consisting of a limitation of the voltage and / or a reduction of the current which traverses the device at a negligible value after a time " determined if the lamp does not light up.
• the control circuit of the semiconductor switch of the preheating function comprises a divider circuit of the resistor type 27 in series with another resistor 24 connected in parallel on a capacitor 23.
• the semiconductor switch for the preheating function is a thyristor 29 or a functioning triac as a thyristor.
• the semiconductor switch of the part of the circuit establishing a high voltage is a component of the TRIAC 17 type, when the trigger circuit of the pulse is charged for 1 alternation for which the potential of B is higher than the potential of A.
• the means for producing a high voltage consists of a capacitor 20 in series with a diode 18 itself connected in parallel on a resistor 19 , all in series with the diode 21 in parallel on the triac 17.
• the basic circuit of the device of the invention shown in FIG. 2 operates as follows: during the alternation where the terminal A is positive with respect to terminal B (positive alternation), the first capacitor 23 charges through the diode 28 according to a law which depends on the resistors 24 and 27.
• the voltage across the terminals of the capacitor 23 reaches the trigger voltage of the DIAC 26 (element also known under the name of "bi-directional Silicon trigger device"), it sends through the resistor 25 and the diac 26 a current pulse in the trigger of the thyristor 29 which becomes conducting. Consequently, a current flows through the ballast 5 (FIG. 1), the filaments l 'of the tube 1, the protection 6, the diode 28, the thyristor 29 and the resistor 16.
• the capacitor 9 is charged according to a time constant essentially dependent on resistors 8 and 10 at a voltage whose value mainly depends on the dimensioning of elements 8, 9 and 10. Note that the presence of diode 7 allows this capacitor to charge in a unidirectional manner and to discharge through the resistor 10, during a cycle of the AC source: the capacitor 9 therefore charges and discharges once per cycle (the diode 7 could be eliminated, but this would result in greater dissipated power in items 8 and 10).
• ⁇ - J * ⁇ * E OM of the capacitor 13 rises in stages at each alter ⁇ nance where the potential of B is positive compared to that of A.
• the capacitor 13 does not discharge once per cycle like the capacitor 9. 3)
• the capacitor 20 charges through the resistor 19 and the diode 21 approximately at the peak value of the network voltage and remains charged at this value as long as the triac 17 is not started.
• the triac 17 When the voltage at the terminals of 13, added to the voltage at the terminals of the resistor 16 (voltage which exists when the preheating current flows), reaches the triggering voltage of diac 15, the triac 17 is triggered. The triac 17 is triggered therefore takes place during the circulation of the preheating current, and as soon as it passes the capacitor 20 forces the current to cancel in the thyristor 29. Note that the diode 22 connected between the means to produce a pulse of high voltage 17 to 21 and the control circuit of the preheating function 23 to 28 prevents the ignition of the thyristor 29 during the release of the ignition pulse of the tube by putting the potential of the connection between 25 and 26 to the potential of the cathode of 29.
• FIG. 4 therefore shows, for reasons of clarification, the voltage present at the terminals of the tube when the latter does not light up, in other words the full pulse of the ignition voltage.
• the aim here is to show that we have mastered the possibility of setting the following parameters:
• the protection of the device is carried out by means of a resistor VDR (voltage dependent resistor) 30 to avoid exceeding the voltage withstand of the components and by means of a nonlinear resistor 6, of PTC type (positive temperature coefficient thermistor) to limit the current to a negligible value if the lamp does not light after a few attempts to start.
• VDR voltage dependent resistor
• PTC type positive temperature coefficient thermistor
• the device of the invention has an almost unlimited lifetime considering the use of semiconductors and passi s entirely static elements. It has no mechanical element subject to wear.
• the device provides pulses largely exceeding 1000 V for a voltage network of 220 V - 15% with a good level of energy.
• Another advantage of the invention consists in that it operates in a very wide range of ambient temperature and even at temperatures below 0 C. e
• the thyristor 29 in FIG. 2 has been replaced by the thyristors 31 and 32.
• the resistor 27 forming a divider with the resistor 24 in FIG. 2 has been replaced by the resistors 34 and 35 which allow, in addition to the role played by 27 , to distribute the voltage of the ignition pulse between the thyristors 31, 32 when they have been blocked by the capacitor 20 and the voltage pulse is in the direct direction (potential A higher than that of B) .
• L r .amorçage 31 and 32 occurs as follows: when the voltage 23 reaches the voltage notede ⁇ ment of the diac 26, the thyristor 32 is initiated and thereby cause the initiation of 31 because the capacitor 23 can supply a current pulse in the trigger of the thyristor 31 via the diode 33 and the thyristor 32 which has just turned on.
• the advantage of the change made in the part intended for preheating is to be able to admit pulse voltages of double value compared to the circuit of figure 2 when using for elements 31 and 32 of the same type as 29 (figure 2 ).
• the cascading ignition of 31 and 32 is possible in the preheating phase since there is at this time, at terminals A and B, only the network voltage which is much lower than the voltage withstand of each of the 2 thyristors.
• the triggers of 31 and 32 are brought back practically to the potential of B by the diode 22. This will prevent a reclosing of 31 and 32 during the duration of the priming pulse.
• FIG. 5 shows a variant of the embodiment shown in FIG. 3.
• Two additional terminals C and D have been created by opening the connection between the thyristors 31 and 32. It may be noted that it is indifferent to open the link between 31 and 32 above the potential link connecting the connection between resistors 34 and 35 and the electrodes- connected in series of 31 and 32, or below this link as shown in Figure 5.
• This connected variant as shown in Figure 6, where the reference 36 represents the circuit of Figure 5, allows the priming of the two tubes L1 and L2.
• FIG. 6 where the filaments FI and F2 of the tube L1 are respectively connected to the terminal A and to the terminal C, while that the filaments FI and F2 of the tube L2 are respectively connected to terminal D and to terminal B; the filament F2 of the tube L1 and the filament FI of the tube L2 being themselves connected in series.
• Figure 7 is another variant of the invention. The part intended for preheating is presented in a manner similar to that of FIG. 2 (elements 22 to 30) but certain components are dimensioned differently.
• the semiconductor switch 37 is a thyristor type component, which means that the control circuit must accumulate energy during the alternation for which the potential of A is higher than the potential. from B.
• FIG. 8 shows an improvement of the circuit of FIG. 7 by making the ignition circuit of the thyristor 37 less dependent on the tolerances of the diacs 15 and 26;
• This can be advantageously achieved by eliminating the capacitance 23 of the preheating control circuit, by replacing the common resistor 24 of the preheating control circuit and of the control circuit of the pulse-releasing switch with a capacitor 39 and a resistor 38 , put in parallel, by adding a resistor 40 in series with the elements 38, 39 above and by inserting a capacitor 41 in parallel on the preceding elements 38, 39 and on the resistor 40.
• FIG. 9 shows another preferred embodiment of the invention in which the number of power semiconductor components is reduced to the unit.
• the circuit ensuring the so-called heating function comprises a semiconductor switch of the GTO 42 type initiated by a circuit of RC command and blocked by a blocking circuit taking into account the preheating time and of which a circuit for developing a voltage pulse supplies a pulse after the blocking of said GTO.
• the GTO blocking circuit takes into account the adequate preheating by the resistor 16 which adds its potential difference which is the image of the preheating current to a potential difference increasing in stages in a capacitor 13 blocking the GTO 42 semiconductor when its poten ⁇ tiel is high enough.
• Elements 23 to 27 and 45 are intended to initiate the GTO 42 to produce preheating by the circulation of a uni ⁇ directional current as in the preceding circuits.
• This preheating current flows in the direction of terminal A, element 6, GTO 42, resistor 16, terminal B.
• the originality of the GTO with respect to the thyristor is that it can be blocked by a sufficient current pulse in the trigger, this current having the opposite direction to that which produces the priming of the GTO.
• the operating principle is analogous to that of the circuits of FIGS.
• the capacitor 13 charges in stages in the negative voltage alternations of the source (potential of B greater than the potential of A) and sends the pulse of blocking at the GTO 42 as soon as the voltage at its terminals plus the voltage at the terminals of the resistor 16 reaches the voltage of the diac threshold 15.
• the current which passed through the GTO 42 before its blocking is transferred to the branch made up of the capacitors 20 and diode 18.
• a voltage pulse which is only limited by the choice of the blocking instant, various resistances (filament - ballast - PTC 6 - resistors 16 and 27), the self-induction coefficient of the ballast 5, VDR resistance 30 and capacity 20, arises ; and initiates the fluorescent tube.
• the capacity 20, unlike the cases of the circuits of Figures 2, 3, 5, 7 and 8 is not charged, at the time of blocking of the GTO 42, at the value of the peak voltage of the network in the direction AB, but to a value which depends on the voltage of the network existing at 1 • boot 42 and the dimensioning of the resistor 19.
• the decrease in the voltage at the terminals of the capacitor 20 occurs in an oscillating circuit whose choice of damping is fixed by the resistors 19 and 27.
• the opto-coupler 44 avoids a reboot semiconductor (GTO) 42, by its photo-transistor. This opto-coupler 44 keeps the capacitor 23 discharged for the duration of the voltage pulse across the tube.
• FIG. 10 Another particularly preferred embodiment of the invention is shown in FIG. 10. It includes a means for reducing the duration of the pulse supplied by the capacitor 13 of the unlocking circuit of the GTO 42.
• This said means advantageously consists of a VDR resistor 47 activating the base of a transistor 49 in parallel on the capacitor 23 of the ignition circuit of the GTO, this transistor 49 avoiding a loading of said capacitor 23, As soon as the threshold of VDR 47 is reached by the pulse voltage, a current flows in the base of the transistor 49 through the diode 45, the VDR 47 and the resistor 48. The capacitor 23 can no longer charge as long as this base current flows.
• the VDR 47 is chosen so that its threshold is higher than the peak voltage of the network so as to allow current to flow only during the voltage pulse.
• the means reducing the duration of the pulse supplied by the capacitor 13 can consist of an avalanche diode activating the base of a transistor 49 in parallel on the capacitor 23 of the ignition circuit of the GTO. Said means can also be advantageously replaced by any element sensitive to tension.
• the circuit providing the preheating function comprises a thyristor 51 in series with the GTO 42 so that these semiconductors are started in cascade and that a higher voltage level is obtained.
• the pulse voltage is distributed over the elements 42 and 51 via the resistors 54 and 50.
• the cascading ignition of the GTO 42 and of the thyristor 51 occurs according to the same principle as for the circuit of FIG. 3: when 42 is primed, the impulse provided by 23 can pass through the trigger of 51 through the resistor 25, the diode 53, the trigger of 51, and the GTO 42 which has primed. Note that the circuits derived from those of FIGS.
• the circuit shown in FIG. 12 makes it possible advantageously to benefit from a high voltage level, for example greater than 2000 V, by using three thyristors 56, 57, 58 primed in cascade. Indeed, it suffices to replace, in the case of FIGS. 3, 7, 8, the circuit part located to the right of the diode 22 by the circuit of FIG. 12.
• the resistors 55, 61, 62 make it possible to distribute the high direct voltage, existing when the priming pulse of the tube takes place, over the three thyristors
• the thyristor 58 is replaced by the GTO 42.
• Such a voltage limiting device can consist for example of diodes connected in series or of a zener diode.
• FIGs 13 and 14 Another way of using the invention to ignite two tubes simultaneously is shown in Figures 13 and 14.
• the device 64 of Figure 13, the details of which are given in Figure 14, is connected to two tubes L1 and L2. connected to the supply network through ballasts 5 and 65.
• the transformation of the dipole device of FIG. 2 into a quadrupole device as shown in FIG. 14, consists essentially of adding the elements 66 to 72 and removing the terminals E and F
• the addition of means 69, 70, 71 comparable to means 18, 19, 20 makes it possible to produce a voltage pulse which ignites the second tube.
• Diodes 67 and 68 allow
• I e The major advantages of this configuration compared to that of FIG. 5 are in particular: I e .
• This configuration allows, by means of an obvious transposition to the diagram of FIG. 3, to obtain higher voltage pulses for each tube. 2 ".
• the addition of elements similar to elements 68 to 72 and connected in a similar manner makes it possible to light a number of additional tubes corresponding to the number of circuits used constituted by these elements, two additional terminals being output for each addition.
• the tube connected on the A-B side plays the pilot tube sheet in the sense that a triggering of the resistance P.T.C. 6 stops the operation of all the tubes connected to the device. On the other hand, the deterioration of any of the other tubes connected to the device does not prevent the others from operating.
• the preheating current of all the tubes connected to the device passes through the thyristor 29 (or the thyristors 31, 32 in the diagram in FIG. 3). So far, only the use of a so-called “uncompensated” arrangement has been described. For various reasons, known per se, it may be necessary to use a compensation capacitor 73, in series with the ballast 5, as shown in FIG. 15.
• the devices described above due to the " uni-directional nature of the current preheating, do not allow to light a tube connected according to Figure 15. However, by making the preheating current bidirectional, it is possible to use the principles described above and to light a tube fluorescent connected as shown in Figure 15.
• the device 74 of Figure 15 includes the means necessary for this purpose.
• FIG. 16 One way of using these means is shown in FIG. 16.
• the device described in FIG. 3 has been taken up by adding the elements 75 to 81 which allow the passage of a preheating current in the direction BA and thus ensure a bidirectional character in preheating.
• the elements 75 to 81 can be arranged so that the triac . 76 is replaced by a conductive thyristor in the BA direction without bringing a different character to the device 74.
• the diode 75 allows the elements 76 to 81 not to have to withstand high voltage when the ignition pulse is released from the tube, while the diode 22 plays the same role as before, namely 1 inactivation of the ignition circuit 31 and 32 during the release of the above pulse.
• Figure 18 explains very well the shapes of the voltages, respectively, of the network and at the terminals of the tube, as well as the shape of the preheating current during the period preceding, as in that which follows, the ignition of the tube.
• the period t -t represents the shapes during preheating.
• the section t ? -t represents the end of the preheating period.
• the ignition pulse is released. From t., The transitional ignition stage (not shown) having passed, we find the system established. It can be seen, without going into details, that the charging of the capacity 13 still takes place as in the case of uncompensated mounting, when the potential of B is greater than that of A and before activation of the triac 76, and that the ignition pulse is released, when the voltage across the terminals of the capacitor 13 added to the voltage drop across the resistor 16, caused by the preheating current flowing in the direction AB reaches the starting voltage of the diac 15.
• FIG. 17 An advantageous execution of the device 74 can be presented as shown in FIG. 17.
• a single bidirectional switch 22 of the triac type replaces the three switches 31, 32 and 76 in FIG. 16.
• the triac 82's priming circuit comprising the elements 23 to 27, 83 and 84, makes it possible to prime the triac 82 in both directions and thus give the bidirectional character to the pre-heating current.
• the diode 22 always plays the role of making the triac 82's ignition circuit inactive during the release of the ignition pulse from the tube.
• the device 74 makes it possible to light a tube in an uncompensated arrangement as well as in a compensated arrangement and therefore confers a universal character on these devices.

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• 1982
  • 1982-02-03 LU LU83920A patent/LU83920A1/fr unknown
• 1983
  • 1983-02-03 EP EP83870010A patent/EP0105042A1/de not_active Withdrawn
  • 1983-02-03 EP EP19830900617 patent/EP0113725A1/de not_active Withdrawn
  • 1983-02-03 WO PCT/BE1983/000003 patent/WO1983002871A1/en not_active Application Discontinuation

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