DE2049606A1 - Ignition circuit for discharge lamps - Google Patents

Description

Patent attorneys

Dr.-lhg. Wilhelm Beichel Dipl-Ing. Wolfgang Mchel

6 Frankfurt a. M. 1
Park street 13

THE GENERAL ELECTRIC COMPANY LIMITED, London, Great Britain Ignition circuit for discharge lamps.

The invention relates to ignition circuits for discharge lamps.

According to the invention an ignition circuit for discharge lamps is characterized in that a voltage transformer device is provided that when relatively low voltages are applied to their primary winding, relatively high voltages its secondary winding for igniting the discharge lamp produces a charging circuit with a Y resistor and a capacitor is connected to the discharge lamp in such a way that when a power supply device is connected to the Discharge lamp gradually increases the charge on the capacitor, and that a discharge circuit with the capacitor is connected, which responds to the increased voltage across the capacitor by, when the voltage a When a certain V / ert is reached, the capacitor is discharged through the primary winding, which results in the relatively low voltages for the voltage transformer device are generated.

The discharge circuit preferably has at least one Semiconductor breakdown component, via which the capacitor is discharged into the primary winding during operation.

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In one embodiment, the semiconductor breakdown component a device with two electrodes (e.g. a breakdown diode) that is in series with the primary winding is connected to the terminals of the capacitor of the charging circuit.

According to a preferred embodiment, however, the semiconductor breakdown component is a semiconductor device with three electrodes, its formed by the two main electrodes Line connected in series with the primary winding to the terminals of the capacitor of the charging circuit Is P, and the discharge circuit has one of the control electrode potential ialjdea component with three electrodes Depending on from the control device controlling the voltage developed on the capacitor.

The semiconductor component with the three electrodes can be a silicon controlled rectifier (thyristor).

The control device may be a semiconductor breakdown device with two electrodes (for example a Zener diode or a breakdown diode) or it can be a resistor circuit (for example, a voltage divider circuit) may be fc.

When the power supply device for the discharge lamp is an AC power supply device, then the charging circuit expediently contains a rectifier device for charging the capacitor of the charging circuit in one direction.

'The charging circuit is preferably constructed in such a way that the effective Time constant of charging the capacitor of the charging circuit is longer than the period of the AC power supply device.

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The charging circuit is preferably designed so that the effective time constant ZAir charging of the capacitor Charging circuit is on the order of a customer or more.

Appropriately, at least part of the V / resistor is designed so that it forms a voltage divider circuit, whereby only a part of the voltage supplied to the charging circuit by the power supply device to the capacitor the charging circuit is passed on.

The circuit is preferably designed so that the running circuit is connected to the terminals of the discharge lamp, but it can also be designed so that the charging circuit is connected to the terminals of the power supply device for the discharge lamp.

The circuit is preferably designed so that the secondary winding are connected to the terminals of the discharge lamp, but it can also be designed so that the secondary winding which is connected in series with the discharge lamp, is connected between the terminals of the power supply device.

A preferred embodiment of the invention is thereby characterized in that the charging circuit and the secondary winding are connected to the same two connecting terminals of the circuit and that these two terminals are connected to the terminals of the discharge lamp during operation.

If the secondary winding of the transformer is in operation to the

Terminals of the discharge lamp is connected, is

preferably a capacitor in series with the secondary winding switched.

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20A9606

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According to the invention, an ignition circuit for a discharge lamp is also provided, which has a device for generating of voltage pulses to ignite the discharge lamp and which is characterized in that the further generation of voltage pulses after a certain operating time of the circuit without ignition of the discharge lamp obstructing protective device is provided. The specific operating time is expediently in the Range from one to five minutes. If the discharge lamp does not ignite with such an ignition circuit, for example, because it is defective, it places useless electrical stress on the ignition circuit and its Associated components and interference frequencies of the circuit prevented over long periods of time.

The protective device is preferably designed in such a way that it prevents the generation of further voltage pulses, when the ignition circuit has been in a state for the predetermined operating time, which is conducive to the generation of the voltage pulses is required. Such an arrangement is further characterized in that the protective device is temperature sensitive Has resistor which is connected such that it is electrically heated when the ignition circuit in Operation is and that the resistance assumes a value after the certain operating time, at which the further Generation of voltage pulses is prevented. At a In another embodiment, the protection device has a capacitor, the charge of which changes when in the Ignition circuit the above-mentioned condition is present, the charge reaching a value after the predetermined time which prevents the further generation of voltage pulses.

We, nn the device for generating the voltage pulses of the The ignition circuit has a breakdown component, for example a thyristor or another semiconductor component

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and the control circuit is adapted to be the breakdown device periodically makes conductive, then the protection device is expediently carried out so that it the this prevents further generation of the voltage pulses, that it changes the operation of the control device. When the control circuit by controlling the charge of a Capacitor is effective, then the protective device is expediently designed so that it continues to generate the voltage pulses prevent the charging of the Capacitor is modified.

If the ignition circuit is carried out according to the invention, then the protective device is expediently arranged so that it prevents that the voltage that forms on the capacitor of the charging circuit, the predetermined value after reached a predetermined time.

The two main features of the invention can be combined.

The invention also includes a discharge lamp with a Ignition circuit according to one or both of the two main features of the invention is provided.

Embodiments of the invention are described below by way of example with reference to the drawings. Show:

Pigur 1 is a partially schematic circuit diagram of the connection preferred embodiments of the invention with a discharge lamp circuit;

Figure 2 is a circuit diagram similar to Pigur 1, but with one other discharge lamp circuit,

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Figures 3, 4, 5 and 6 are circuit diagrams of four different preferred embodiments of the Invention and

FIGS. 7 and 8 are incomplete, partially schematic circuit diagrams of modified embodiments of the invention.

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In Pigur 1 the embodiments are according to the invention Arrangement shown as a two-pole ignition circuit 1, the terminals 2 and 3 ', the input and form the output terminals of the ignition circuit and which are connected to terminals 4 and 5 of a discharge lamp 6 are "to be, via a control and protection device 9 is connected to terminals 7 and 8 of a power supply device. The device 9 can, for example, at least a tapped or untapped inductor and / or other ballast (e.g. an electronic ballast) and / or at least one transformer and a power factor .have correcting capacitor. The ignition circuit 1 " can thus, if necessary, separately from the discharge lamp 6, the control and protection device 9 and the Terminals 7 and 8 of the power supply device may be provided, the connection being made by two wires from the connection terminals 4 and 5 to the terminals 2 and 3 respectively. The ignition circuit 1 can therefore be relatively simple Way to be added to the already existing circuit of the discharge lamp.

The ignition circuit 1 is constructed so that it operates on the voltage responds, which arises between the lamp connection terminals 4 and 5 by uie power supply device by generating pulses from j | Relatively greater voltage is generated, which in turn is caused by the ignition circuit 1 are fed to the terminals 4 and 5, where-Qby the discharge lamp 6 is started.

In the arrangements described, it is assumed that the terminals 7 and 8 of the power supply device with the power supply device via an on-off switch (generally known design) are connected to control ües operation of the lamp. In the described arrangements it is assumed that that the power supply device is an AC power supply device however, a direct current power supply device can also be used.

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The arrangements described assume that the lamp is a high pressure sodium vapor lamp, but may other high-pressure discharge lamps and also low-pressure discharge lamps can also be provided. ..

In FIG. 2, a particularly modified embodiment of the circuit according to FIG. 1 is shown. In this embodiment, the control and protection device 9 has a ballast ' device 10, which is connected to the series-connected discharge lamp 6 is connected to the terminals 7 and 8 of the power supply device, with a series connection the power factor correcting capacitor 11 is connected in parallel to P.

FIG. 3 shows a circuit diagram of an embodiment of the ignition circuit 1. A voltage divider circuit with resistors R ₁ , Rp, R? and R. connected. The resistor R ₁ is connected in series with the resistor R, with a series circuit of the resistors R ₂ and R being connected in parallel with the resistor R. Resistor R ₂ is a thermistor (see below).

The output voltage of the voltage divider circuit tapped at the resistor R. is _{fed via a rectifier diode λ D 1 to} an electrolytic capacitor C ₁ , to which firstly a series circuit consisting of the cathode-anode path of a thyristor (controlled silicon rectifier) SCR ₁ and the primary winding of a voltage-increasing capacitor Pulse transformer T ₁ and also a Zener diode Z ₁ , which is connected in series with the control electrode-cathode path of the thyristor SCR ₁ , are connected in parallel.

The secondary winding of the transformer T ₁ is connected in series with an auxiliary capacitor C ₂ between the terminals 2 and 3. According to Figures 1 and 2, the control and protection device 9 (for example, the ballast 10 and the capacitor 11) and the discharge lamp 6 are so constructed that in general when connecting an alternating current

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Power supply device with the terminals 7 and 8 before the ignition of the discharge lamp 6 and then when there is no ignition circuit 1 is connected, a relatively large AC voltage (the power supply frequency) across the discharge lamp 6 develops, the AC voltage being reduced when the discharge lamp 6 has been ignited. The circuit after Figure 3 takes advantage of this process and is therefore designed (see below) that between the terminals 2 and 3 a Impedance which is large enough (at the power supply frequency) is that it affects the discharge lamp 6 only a small one It exerts a secondary effect, thereby reducing the alternating voltage only little affected. .. · :.

The circuit of Figure 3 thus operates in the following way. When connecting an AC power supply device with the connection terminals 7 and 8 (Figures 1, 2) occurs before the ignition of the discharge lamp 6, a fraction of the relatively large AC voltage across the resistor R ^ so that the capacitor Cj during alternating half-waves of voltage in one Direction is being charged.

The rate of rise of the rectified charge on the capacitor C ₁ and the voltage on this capacitor is determined by the effective time constant of the resistor-capacitor circuit formed by Cj and R ₁ , and this time constant is made relatively large in the arrangement according to the invention . Thus, if the power supply device connected to the connection terminals 7 and 8 (Figures 1 and 2) is an AC power supply device, then the time constant (contrary to common practice) is made larger than the period of the AC current. In a typical arrangement where the power supply device may be a DC power supply device or an AC power supply device, the effective time constant may be on the order of a second or more.

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The capacitor G ₁ is charged up to a final voltage which is lower than the alternating voltage which is formed at the discharge lamp 6 and which is determined by the voltage divider circuit.

The Zener diode Z- is selected so (with regard to its breakdown voltage at which a current conduction occurs in the reverse direction) and together with the thyristor SCR ₁ ao et together that the Zener diode breaks down and ignites the thyristor via the control electrode when the rectified voltage, which has _{formed across the capacitor C 1} , reaches a certain value which is, for the most part, somewhat lower than the value of the final voltage.

Triggering the thyristor SCR _1, the capacitor _C1 begins through the anode-cathode path thereby in the secondary winding a Hochspahnungsimpuls is generated / the discharge of the capacitor C ₁ is sufficient to discharge the thyristor in the primary winding of the transformer T _1, to both the effect of magnetization of the transformer T ₁ and also any load on the secondary winding which may be caused by ionization in the discharge lamp 6 before the lamp is ignited. The beginning of the discharge of the capacitor C ₁ into the primary winding generates a sequence of damped electrical oscillations of relatively high frequency in the primary winding and in the secondary winding of the transformer T ₁ (for example of 200 kHz. In each sequence of oscillations in the secondary winding, the first generates Half-wave the above-mentioned high-voltage pulse, which is to be used primarily to ignite the discharge lamp 6. The oscillations in the primary winding seek to change the discharge of the capacitor C ₁ via the anoxia-cathode path of the thyristor of the oscillations decay, while the capacitor C ₁ seeks to discharge completely until the anovden-cathode path of the thyristor SCR ₁ becomes non-conductive.

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If the discharge lamp 6 has not been ignited, then the capacitor C is then charged again in one direction up to the final voltage until the thyristor SCR ₁ is ignited again.

The relatively low repetition frequency of the high-voltage pulses / is determined by the relatively large (see above) effective time constant when the capacitor C _{1 is} charged. Heretofore, it has been considered that a pulse repetition frequency which is not less than the frequency of the AC power supply device is required in order to light a discharge lamp 6 of the high pressure discharge type. It has been found, however, that with suitable circuits which generate high-voltage pulses of sufficient pulse length and power, such a relatively high pulse repetition frequency is not necessary. This reduction in the pulse repetition frequency reduces the risk of radio interference from the network.

If the circuit according to Figure 3 is used as an ignition circuit 1 for discharge lamp circuits, as shown in Figures 1 and 2, is used, then the control and protection device acts 9 (for example the ballast 10 and the capacitor 11 in Figure 2) generally as a low-pass filter that prevents that the high voltage pulses high frequencies in the Power supply device, which is connected to the terminals 7 and 8, generate.

When the discharge lamp 6 is ignited, the alternating voltage generated at the lamp (see above) is reduced, as a result of which the voltage that is fed to the voltage divider circuit is reduced and as a result of which, in turn, the final voltage of the capacitor C ₁ drops to a value which is insufficient for a breakdown cause the Zener diode Z ₁ in the reverse direction. As a result, the thyristor SCR ₁ is no longer ignited, which prevents the further generation of high-voltage pulses.

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If, however, the discharge lamp 6 does not ignite, then the relatively high alternating voltage will continue to be applied to the discharge lamp 6 and consequently will continue to be supplied to the voltage divider circuit. The thermistor R ₂ is selected and switched in relation to the other resistors of the voltage divider circuit in such a way that the continued application of the relatively high voltage causes the thermistor Kp to heat up to such an extent that its resistance after a certain period of time (two years after about one to five Minutes) begins to decrease to a value which is sufficiently small that the final voltage of the capacitor C ₁ sof / is reduced so that the _{capacitor P sator cannot cause the Zener diode Z 1} to break down in the reverse direction. The thyristor SGJi ₁ can therefore no longer ignite, which prevents the further generation of high-voltage pulses. This is advantageous because the continued concern of the high-voltage pulses for the Pail that the discharge lamp does not ignite puts stress on the connections of the ignition circuit and the lamp circuit and creates the risk of radio interference.

The heating of the thermistor Rp can be assisted by providing an effective thermal coupling (16, FIG. 3) between the thermistor Rp ^{UJ1 (} * ^ ^em resistor R ₁ , where C is the heating of the resistor R ₁ when the relatively large alternating voltage is applied to the thermistor Rp. For example, the thermistor Rp can be arranged close to the resistor R ₁ or in the (hollow) resistor R ₁ .

If the power supply device for the discharge lamp 6 is switched off, then when the power supply device is switched on again the circuit according to Figure 3 automatically begin to work again. When the discharge lamp 6 is not has ignited and is replaced without the power supply device at terminals 7 and 8 being switched off, then the circuit of Figure 3 by short-circuiting the lamps, connecting terminals 4 and 5 for a time that is sufficient the thermistor Rp can cool down sufficiently, in the normal loading

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2CH96Ü6

instinctual state brought back

O ^v

As already mentioned above, the circuit according to Figure 3 is designed so that it has an impedance between the terminals 2 and 3, which (at the power supply frequency of an AC power supply device, is to be fed by the button charge lamp 6), is large enough that for the discharge lamp 6 only has a slight shunt effect. This is achieved on the one hand in that the sizes of the resistors of the energy-saving divider circuit are selected in such a way that the impedance that is created by this circuit part between terminals 2 and 3 at the power supply frequency is relatively large and that, on the other hand, a capacitor C ₀ with a relatively small capacitance is selected, whereby it has a relatively large impedance in the power supply frequency. With such a structure, the high voltage pulses generated in the secondary winding are not excessively loaded by the voltage dividing circuit.

A further advantage of this circuit arrangement with high impedance is that the circuit according to FIG with relatively low voltages (which in particular contains the capacitor 0 | the Zener diode Z ₁ and the thyristor SCRh, all of these components only having to have relatively low nominal voltage values).

A typical circuit according to FIG. 3, in which the discharge lamp 6 is to be excited by an AC power supply device with 50 Hz and a voltage of 200 bin 2-> 0 V, have the values of fL, R, and R, 39, 3, 3 and 39 kiloohms, R ₂ iat a thermistor of the type ϋ-ί34Β with a cold resistance in the order of 50 ohms, D ₁ iat a rectifier diode of the type PL4003 (200 volt) »Cj iat a 50 volt electrolytic capacitor

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-H-

Sator with 50 microfarads, Zj is a Zener diode of the type IN4179 (50 volts), SCR ₁ is a thyristor of the type MCR 406-2 (60 volts), T ₁ has a bond ratio of 3: '380 and Cp is a capacitor of 10 kpF (300 volts alternating voltage). With such values of the circuit arrangement, the product C ₁ , R _{1 has} a value of about 2 seconds, so that the effective charging time constant of the capacitor C, is about 4 seconds (because when using an AC power supply device, the capacitor C ₁ only during the alternating Half-waves is charged). Through the -Scha Ltung about every four seconds ^ between terminals 2 and 3 a sequence of damped oscillations with a frequency of about 200 kHz is generated. The first oscillation of each oscillation, ie the high-voltage pulse3, has an amplitude of about 4.7 kV and a pulse length of about 5 microseconds.

. The circuit of Figure 4 is similar to the circuit of Figure with the exception that the Spjrinungstellerschaltung is constructed somewhat differently and has three resistors R _5, Rg and R ₇ , which are connected in series, the resistor Rg is a thermistor, the thermal (similar to FIG. 3) is connected to the resistor R ^ and the output voltage of the voltage divider circuit is taken from the series-connected resistors Rg and R ^. The operation and the arrangement of the circuit according to FIG. 4 are also similar in other respects to those of the circuit according to FIG Type CZ 10 is suitable as a thermistor (which has a cold resistance of 4.7 kilo ohms).

The circuit according to FIG. 5 is essentially similar to the circuits according to FIG. 3 and FIG. 4 with the exception of the circuit part which controls _{the charging of the capacitor C 1.} In the circuit of Figure 5, the terminal 2 is a series circuit of a resistor R ^ a Zener diode Z ₂ and a

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-Vj-

Rectifier diode I) _? connected with ο in a straight point 19, which is connected via nine series connection of the V / i de rat and en R ₍ and h 'with the Λη.κ; π] terminal 3 int. The common point 19 is also connected via a Resistor K ₁₁ connected to a Ansohluli 20 of the condt-n.'jators C, think another connection with the connection terminal 3 is connected.

Dem vri dcj;. ; .a]] u ~ E ₁ ο is parallel in Elekrr ^ lvtj.cndeniiator G _7; üBohaltt.t, the. run-turn a sound Urre in a Z-di ^ ae Γ-ν in series with the emitter Barn "-Ütr ^ cj. _TT nines l'ranai; tors y., Parallf-l connected irit, the 3! 'OJ3 i ^j 3 \ 1 or de; i Tj'anaiiitcj-ii X ₁ via a V / ideratand 3i _1o with il (? M connection ? .O

UI) CJ "UJJJIiJi H J-UUi."!.; t-rl JJU JI-ι ο ^{ÜJ L 1} ^ " ^ιί ill Jv i JiJ <; 1J Λ. U Iv <; w

i β t.

Boron transistor X ₁ 1st (as will be explained further below) i;>j'Li; j] er ''< Um not conductive, so that it l ·. an influence on the jiUi laden oe.n capacitor ^ ₁ bat. If now the circuit according to F;., ^ Ur ',' /, (v.'ie mentioned above) is connected to a y, nt-! 3charge valve 6 angeooiilo. ·, 'Jtrouiverscrgungsvcri-ie-htn ;;,' is whistled, then work for you? V / iöerstands I:; _J , I · ... and R .., aiii opensionstei ler-üchal tion, one of which AU3-gi-ngsijpajjnvaig of the in series ^ e ^ cbalti-te-n resistors It ,, una R ₁ , given in order, as si-hon mentioned, an end

generate voltage su on the dt: -i iondunsator C ₁ via the {

V / resistance R ₁₁ can be charged «

The Gleiohriehterdiode I) ₀ v.'irüit äluil I, v / ie the above-mentioned rectifier diode D ₁ , but in the present embodiment it is only possible for alternating cold waves of the AC voltage (the power supply frequency) that is applied to the discharge lamp 6, a Current through the voltage divider circuit to flow.

In the present embodiment, the effective time constant of the resistor-capacitor circuit, which is formed by C ₁ , Rr, and R ₁₁ / re, is again made relatively large, as already described above.

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BAD ORtOINAL

As long as' remains nonconductive, the transistor X _1, the circuit like the circuits of the thyristor SCR ₁ operates according to Figure 5 in substantially the same manner according to Figures 3 and 4 wherein prior to ignition of the discharge lamp 6 repeatedly ignited to generate high voltage pulses, while in When the discharge lamp 6 is ignited, unlike in the circuits described so far, no voltage is formed across the capacitor C ₁ . The absence of the voltage on capacitor C ₁ prevents further generation of pulses.

The transistor X ₁ is switched in such a way that it becomes conductive if the lamp does not ignite after a certain time after the occurrence of the relatively high alternating voltage (the power supply frequency) at the discharge lamp 6. If, consequently, this alternating voltage is still present, then the capacitor C, is charged in one direction, the rate of increase in charge being determined by the effective time constant of the resistor-capacitor circuit formed by Cz, R _Q and Rq and the final voltage of the capacitor C, is determined by the voltage dividing circuit. The circuit arrangement is designed so that if after a certain time (expediently in the order of 1 to 5 minutes) the discharge lamp 6 has not ignited,

w the voltage developed across the capacitor C · * becomes sufficiently large that a breakdown of the Zener diode Z ·? takes place in the reverse direction, whereby the transistor X ₁ becomes conductive and whereby the resistor R _{12 is connected in} parallel with the capacitor C ₁ , which means that the final voltage of the capacitor C _{1 is} sufficiently reduced so that further ignition of the thyristor SCR _{1 is} prevented . If the transistor X ₁ has been made conductive, then the remaining overhang of the capacitor C- is relatively small, so that the charge on the capacitor is sufficient, however, to maintain the conductive state of the transistor.

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If, however, the discharge lamp 6 does not ignite, then the alternating voltage (the power supply frequency) which occurs at the ignited discharge lamp during the conductive half-waves of the rectifier diode D _{2 can} be sufficient to charge the capacitor G i sufficiently so that the transistor X. _{1 is switched} to its conductive state. This is prevented by the Zener diode Z ₂ , which is connected in the opposite direction to the rectifier diode Dp.

In a typical circuit according to FIG. 5, C ₁ , Ζ-. , SCR ₁ , T ₁ and C _{2 use} the same components as in the circuit according to Figure 3. The resistors Rg, Rg, R-jq »R ₁₁ and R ₁₂ have values of 39 kilohms ,, 2.2 megohms, 2, 2 megohms, 10 kilohms or 2.2 kilohms, as rectifier diode D ₂ the type PL4004 (400 volts), as zener diodes Z ₂ and Z ₅ the types IN4192 (180 volts) or ' MR56 (5.6 volts), a 400 microfarad electr. Capacitor (6 volts) used _{as C 5} and the type 2N4289 used _{as transistor X 1.}

The circuit according to FIG. 6 corresponds to the circuit according to FIG. 5 with the exception that the resistor R _{12 is} replaced by a rectifier Vxliode D ^, which is polarized so that the capacitor C ₁ tries to discharge through the rectifier diode D, when the transistor X ₁ in its conductive state, the circuit operates substantially the same as the circuit of Figure 5 with the exception that in the circuit of Fig., the resistance R ₁₂ to the capacitor via the transistor X _1, while it is in its conductive state is located, can discharge when the thyristor SCR _{1 is} in its conductive state, whereas the alternatively provided rectifier diode Dz seeks to prevent this.

In a typical circuit of Figure 6, the components are the same in the circuit of Figure 5 with the exception that C, a 320 microfarad electrolytic capacitor (6 volts) and

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- 18 D, which is a rectifier diode of type D53 (40 volts).

In a modified embodiment of the circuits according to Figures 3 to 6, the thyristor can be replaced by another semiconductor component with 3 electrodes, and / or the Z-mode Z ₁ can be replaced by another control device that controls the control electrode of the semiconductor component depending on the Controls the voltage across the capacitance C _1. The control device can contain, for example, an avalanche breakdown diode or another semiconductor _{component as a substitute for the Zener diode Z 1} , or it can have an arrangement of • resistors (for example a voltage divider _{circuit that is connected in parallel to the capacitor C 1} , which emits an output voltage that the control electrode-cathode path of the semiconductor component is supplied.). . On the other hand, the thyristor SCR _{1 can} also be replaced by a semiconductor component with two electrodes (e.g. an avalanche breakdown diode), which is connected in _{parallel with the primary winding in series with the capacitor C 1} , in which case the Zener diode Z _{1 is} omitted. In a further modified embodiment of the circuits, the half- _{wave rectifiers D 1} or D _{2 can be} replaced by full-wave rectifiers. Furthermore, the transistor X ₁ and / or the Zener diode Zz can be replaced by corresponding components (in general, as indicated at the beginning of this paragraph for the thyristor SCR ₁ ). The transformer T ₁ can also be replaced by an inductance provided with a tap (compare FIGS. 7 and 8).

If the circuits according to Figures 3 to 6 a discharge lamp to ignite from a DC power supply device is fed, then the power supply device must be constructed so that it is suitable for the rate of change of the pulses that have passed has a high impedance, i.e. it has a small reactive component. The input impedance

the circuits would have to be artificially increased to the minimum

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Current in the conductive state through the discharge device to a "certain value, and to prevent a large change in the pulse rate.

FIG. 7 shows an incomplete circuit diagram, partly in a block diagram, which represents a modified embodiment of the invention. ^{In this Pail the discharge lamp 6 is connected to the} power supply connection terminals 7 and 8 via the secondary winding of a voltage increasing transformer s T ₂ ^m ^ (between which a power factor correcting capacitor 11 is connected). The ignition circuit 50 is constructed in the same way as in FIGS. 3 to 6 with the exception that the capacitor Ci is now provided for discharge via the thyristor SCR- into the primary winding of the transformer C ₂ . Consequently, in this case the transformer T- is replaced by the transformer T ₂ , the secondary winding of which acts as a ballast inductor for the discharge lamp 6 and also emits high-voltage pulses in the manner described above. In a further embodiment of the invention, the transformer T ₂ (FIG. 7) can be replaced by an inductance L provided with a tap (as indicated in FIG. 1).

In a further embodiment of the circuits described, the voltage divider circuit, which is connected between the terminals 2 and 3 of the ignition circuit, is not connected to the terminals 4 and 5 of the discharge lamp 6 but to the terminals 7 and 8 of the power supply device. In this case, the secondary winding (together with the capacitor Cp connected in series) can be connected between the lamp connection terminals 4 and 5, or the transformer T ₂ or the tapping inductor L can be as shown in FIGS is to be used. In this case, the capacitor C ^ the 'thyristor SCR. continue to ignite after the discharge lamp .6 has been ignited until this mode of operation is

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Switching action of the thermistor Rp (Figure 3) or Rg (Figure 4) or the capacitor C, (Figures 5, 6) is interrupted.

109818/1537

Claims (26)

Claims / 1 / Ignition circuit for discharge lamps, characterized in that a voltage transformer device (T ₁ ) is provided which, when relatively low voltages are applied to its primary winding, generates relatively high voltages on its secondary winding to ignite the discharge lamp (6), so that a charging circuit (C, , R ₁ ; C ₁ , R _Q ) with a resistor (R ₁ or RqJ etc.) and a capacitor (C ₁ ) is connected to the discharge lamp (6) in such a way that when a power supply device is connected to the discharge lamp, the Charge on the capacitor (C ₁ ) gradually increases, and that a discharge circuit (Z ₁ , SCR ₁ ) is connected to the capacitor (C ₁ ), which responds to the voltage that has grown on the capacitor by, when the voltage a reaches a certain value, discharges the capacitor through the primary winding, whereby the relatively low voltages for the voltage transformer _{device (T 1} ) are generated. 2. Ignition circuit according to claim 1, characterized in that the discharge circuit has at least one semiconductor _{breakdown component (Z 1} ) via which the capacitor (C ₁ ) is discharged into the primary winding during operation. 3. Ignition circuit according to claim 2, characterized in that the semiconductor breakdown component is a component with two electrodes which is connected in series with the primary winding to the terminals of the capacitor (C ₁ ). 109819/1337 4. Ignition circuit according to claim 2, characterized in that that the semiconductor breakdown component is a semiconductor component with three electrodes, whose path formed by the two main electrodes is connected in series with the primary winding to the terminals of the capacitor (C ₁ ), and that the discharge circuit is the control electrode potential of the component with three electrodes as a function of the on the capacitor (C ₁ ) developed voltage controlling control device. 5. Ignition circuit according to claim 4, characterized in that that the three-electrode semiconductor device »a controlled one Silicon rectifier is. 6. ignition circuit according to claim 4 or 5 »characterized in that that the control device is a semiconductor breakdown device with two electrodes. 7. ignition circuit according to claim 4 or 5, characterized in that P that the control device comprises a resistance circuit. 8. Ignition circuit according to one of the preceding claims, characterized, that the power supply device for the discharge lamp (6) is an AC power supply device, and that the charging circuit comprises a rectifying device (D ₁ ; Dg) for charging the capacitor (C ₁ ) in one direction. 9. Ignition circuit according to one of the preceding claims, characterized in that that the resistor is designed so that it is a voltage divider eo posture forms, eliminating only part of the tension exerted by the 109818/1337 20A9G06 Power supply device is supplied to the charging circuit, is passed _{to the capacitor (C 1) of the charging circuit.} 10. Ignition circuit according to one of the preceding claims, characterized in that the power supply device for the discharge lamp (6) is an AC power supply device, the effective time constant of the capacitor (C ₁ ) of the charging circuit being longer than the period of the alternating current Power supply device. 11. Ignition circuit according to one of the preceding claims, characterized in that the effective time constant of the capacitor (C ₁ ) of the charging circuit is of the order of one second more. 12. Ignition circuit according to one of the preceding Are claims, characterized in that the secondary winding with the terminals (4, 5) of the Discharge lamp (6) is connected during operation. 13. Ignition circuit according to claim 12,
thereby ge, ke η η ζ ei ch η et * that a second capacitor (C ₂ ) is connected in series with the secondary winding. 14. Ignition circuit according to one of the preceding claims, characterized in that that the charging circuit is connected to the terminals (4,5) of the discharge lamp (6) during operation. 109818/1337 20A9606 15. Ignition circuit according to claim H, depending on Claim 12, characterized, that the charging circuit and the secondary winding are connected to the same two terminals and that during operation these two terminals are connected to the terminals (4, 5) of the discharge lamp (6). 16. Ignition circuit for a discharge lamp with a device to generate voltage pulses to ignite the Discharge lamp, characterized, that a further generation of voltage pulses after a protective device (Rp or Rg, 16) is provided. 17. ignition circuit according to claim 16,
characterized, that the specific operating time is on the order of one to five minutes. 18. Ignition circuit according to claim 16 or 17, characterized in that that the protective device (Rp or Rg, 16) constructed in such a way is that the generation of further voltage pulses is prevented when the ignition circuit for the predetermined operating time has exhibited a condition required to generate the voltage pulses. 19 ignition circuit according to claim 18,
characterized in that the protective device has a temperature-sensitive resistor (R ₂ or Rg) which is connected in such a way that it is electrically heated when the operating state is present in the ignition circuit, and that the resistance assumes a value after the certain operating time at which prevents the further generation of voltage pulses. 109818/1337 20. Ignition circuit according to claim 18, characterized, that the protective device has a capacitor (C *), whose charge determines the electrical operating state in the ignition circuit (1) changed, and that the charge after the predetermined operating time assumes a value at which the further Generation of voltage pulses is prevented. 21. Ignition circuit according to one of claims 16 to 20, characterized in that that the device for generating the voltage pulses Has breakdown component and a control circuit which is connected such that it has the breakdown component periodically makes conductive, and that the protective device is designed such that the further generation of voltage pulses is prevented by modifying the operating mode of the control circuit. 22. Ignition circuit according to claim 21, characterized in that that the control circuit controls the charging of a capacitor (C-z) and that the protection device is designed in this way is that the further generation of voltage pulses through Change - to charge the capacitor (C- *) prevented 23. Ignition circuit according to claim 22, depending on claim 19, characterized, that the breakdown device conducts when the charge on the control circuit capacitor reaches a certain value and that the value which the temperature-sensitive resistor assumes after the predetermined operating time is so large is that the charge on the * control circuit capacitor is attached is prevented from reaching the predetermined value. 109818/1337 24. Ignition circuit according to claim 22, depending on claim 20, characterized in that the breakdown device conducts when the charge is on the Control circuit capacitor reaches a certain value and that the charge that forms on the protective device capacitor after the predetermined operating time is so great that the charge> on the control circuit capacitor the predetermined Value cannot achieve. 25. Ignition circuit according to claim 24, characterized in that that the protection device has a transistor (X-.), its Eraitter-collector route to the Steuerachaltungskondensator (C.,) is connected in parallel and that the transistor (X-) is also switched in such a way that it is replaced after a certain operating time by the charge that is on the protective device capacitor (C ^) has accumulated, made conductive will. :. 26. Ignition circuit according to one of claims 1 to 15 «and one of claims 16 to 25, characterized in that the protective device prevents the voltage on the Capacitor in the charging circuit reaches the predetermined value after the predetermined operating time. Rei / diW 109818/1337