EP1494510B1 - Ignition apparatus with intelligent disconnection - Google Patents

Abstract

The controlled high voltage generator (11) connected to the lamp (1), supplies start- or ignition impulses. A control circuit (12) connected to it (11) controls it in different modes. The cold start detection unit is connected to or forms part of the control circuit. A re-settable extinction counter is also connected to or forms part of this circuit. It counts extinctions and/or start pulses. It is designed to prevent further starting attempts until the next cold start, when a given number is reached. A timer (38) is triggered on starting of the gas discharge lamp and is connected to an extinction counter. This resets the counter on expiry of its triggering time.

Description

The invention relates to an ignitor for gas discharge lamps, in particular with electromagnetic ballast and a method for igniting and re-igniting gas discharge lamps.

Gas discharge lamps such as sodium vapor lamps, metal halide lamps, in particular when they are designed as high-pressure gas discharge lamps, are usually sensitive to mains voltage fluctuations. The mains voltage superimposed interference voltages can bring the high-pressure gas discharge lamps to extinction. The re-ignition usually requires a lamp-dependent time, which can range from a few seconds to several minutes. This is especially true if the igniter emits ignition voltage, which are sufficient to ignite a cold but not to ignite a hot lamp.

If mains faults are found, this leads to the extinction of individual high-pressure gas discharge lamps, which then have to be re-ignited.

A fundamentally different process takes place when the gas discharge lamp approaches its end of life. The burning voltage then increases to values that can lead to the stochastic extinction of the gas discharge lamp. Also in this case, an ignitor re-ignites the lamp, but the gas discharge lamp usually goes out as soon as it burns and heats up as its burning voltage increases. Because of the hazards associated with the operation of aged lamps and because of the annoying flashing of such lamps, it has therefore become known to detect the number of ignition attempts. For this purpose, EP 0 847 680 B1 discloses a method for operating or igniting high-pressure gas discharge lamps, in which the number of lamp ignitions is counted after an unintentional switch-off of the lamp and the ignition circuit is switched off if the lamp unintentionally returns after a predetermined number of lamp ignitions off.

This is also known from US-PS 4,853,599. This publication also discloses a ballast or ignitor that detects the number of reclosing operations and shuts off when a predetermined number.

Although such igniters can prevent the unwanted flashing of high-pressure gas discharge lamps. On the other hand, they also tend to be completely intact high-pressure gas discharge lamps even though they have not reached their end of life yet. This effect depends on the power quality. Occur occasional, lamp extinguishing leading to network disturbances and cause an unintentional shutdown, ie extinguishing the high pressure gas discharge lamp these deletion or shutdown operations are counted. In networks with high levels of interference, this can lead to the shutdown of intact lamps, which is not intended. This is particularly undesirable in continuous lighting, such as road tunnels.

US-A-5 969 483 describes a ballast for fluorescent lamps with preheated electrodes. To detect inoperable lamps, a monitoring device is provided which counts the ignition attempts and switches off when a certain number of ignition attempts is exceeded. This principle can not be applied to high-pressure discharge lamps because they switch off at the end of their life, e.g. every hour. It is difficult to distinguish such turn-offs induced by reaching end-of-life from turn-offs caused by line disturbances, i. the mains voltage superimposed interference pulses are caused.

On this basis, it is an object of the invention to provide an ignitor for high-pressure gas discharge lamps and corresponding method for the operation of high-pressure gas discharge lamps, with which the shutdown intact gas discharge lamps can be largely avoided after unintentional shutdown.

This object is achieved with the ignition device according to claim 1 and with the ignition method according to claim 4:

The solution to the problem lies in determining a critical burning time and monitoring whether the high-pressure gas discharge lamp burns for longer than this time. If the high-pressure gas discharge lamp meets this condition, it is classified as operable and continues to operate. However, if it switches off within the critical burning time, this is registered. If several such registrations follow each other, these registrations are counted. If the count value exceeds a predetermined or alternatively also predefinable value, the lamp is classified as worn and stopped. For example, this value is set to three events. However, it can be set larger or smaller as needed. The critical firing time is set to be on the one hand so great that a periodic extinction occurring at the end of the life occurs at intervals shorter than the critical firing time, while on the other hand the probability of several consecutive power disturbances that can lead to lamp extinction within the critical burning time is very low. For example, the critical burning time can be set to one or more hours.

With the monitoring of the compliance of the critical burning time or the non-successive undershooting of the same, a practically very safe distinction of Lampenlöschüngen that occur at the end of life, and lamp erasures that occur as a result of network interference is achieved.

The ignitor contains a discriminator to distinguish between cold and warm start. This discriminator, which is also referred to as a cold-start detection device, preferably sets the resettable extinguishing counter to its initial value upon detection of a cold start, so that high-pressure gas discharge lamps switched off as a defect even in the preceding firing cycle be ignited first. If the counter is set to the value 3, it remains permanently switched off after the third unintentional extinguishing, until the next cold start. If, for example, business locations, other public spaces or other rooms requiring continuous lighting, such as tunnels and the like, are being maintained, all lamps will be ignited at the next start of operation, even those which, as a consequence, turn off unlikely but possible short-term successive network disturbances to have. After a short wait, the ignitors have then switched off the really defective lamps. They can then be replaced. In the case of business expenses and similar lighting that is switched off periodically every day and only lights up at night, the distinction between cold and warm start ensures that all lamps are started during a cold start (switching on the lamps in the evening, for example) and after a settling time Switching off the defective lamps no lamp is flashing anymore.

Further details of advantageous embodiments of the invention are the subject of the drawing, the description or subclaims.

Figur 1 bis 3

Gasentladungslampen mit Vorschalt- und Zündgerät in unterschiedlichen Ausführungsformen in schematisierten Schaltbildern,

Figur 3a

eine Steuerschaltung für die Vorschaltgeräte nach Figur 1 bis 3 in vereinfachter Darstellung,

Figur 4

eine andere Steuerschaltung für die Vorschaltgeräte nach Figur 1 bis 3 in vereinfachter Darstellung,

Figur 4a, 4b

Schaltungsvarianten für eine Erkennungseinrichtung,

Figur 5

einen Teil der Steuerschaltung nach Figur 4 als Blockschaltbild und

Figur 6

ein Zeitdiagramm zur Veranschaulichung der Betriebsweise des Zündgeräts.

In the drawings, embodiments of the invention are illustrated. Show it:

Figure 1 to 3

Gas discharge lamps with ballast and ignitor in different embodiments in schematized circuit diagrams,

FIG. 3a

a control circuit for the ballasts of Figure 1 to 3 in a simplified representation,

FIG. 4

another control circuit for the ballasts of Figure 1 to 3 in a simplified representation,

Figure 4a, 4b

Circuit variants for a detection device,

FIG. 5

a part of the control circuit of Figure 4 as a block diagram and

FIG. 6

a timing diagram illustrating the operation of the igniter.

1 shows the circuit diagram of a gas discharge lamp 1 and an associated ballast 2 and an ignitor 3 is illustrated. The gas discharge lamp 1 is, for example, a sodium vapor lamp, a metal halide lamp or another gas discharge lamp. While one terminal is connected to a reference potential N, its other terminal is connected via an ignition pulse transformer 4 and the ballast 2 to an AC voltage-carrying line L. The reference potential N and the line L can be interchanged with each other. The ballast 2 consists in the simplest case of a series reactor which serves to limit the lamp current of the gas discharge lamp 1 and to stabilize the gas discharge. The Zündimpulstransformator 4 has a secondary winding which is connected between the ballast 2 and the gas discharge lamp 1. Its primary winding is connected to the ignitor 3. This contains a firing capacitor 5, which is connected at one end to the primary winding of the ignition pulse transformer 4 and at the same time to one end of the secondary winding and to the ballast 2. With its other end it is connected to an intermediate potential 6. The other end of the primary winding of the ignition pulse transformer 4 is connected via a breakdown switch device, such as the Sidac 7, whose other end is connected to the intermediate potential 6. The latter is connected via a current limiting resistor 8 and a capacitor 9 to the reference potential N. The Zündimpulstransformator 4 together with the ignitor 3, a high voltage generator 11. This is associated with a control circuit 12, the terminals 13, 14 are connected in the sense of a parallel connection to the Sidac 7. The control circuit 12 can also be connected in parallel with the capacitor 5. The control circuit 12 is out of sight Sidacs 7 a switch 15, which can short-circuit the Sidac 7, to prevent the generation of ignition pulses.

The control circuit 12 includes an electronic circuit 16 for driving the switch 15. The control circuit monitors to the voltage applied to the terminals 13, 14 voltage and evaluates them. It is formed in the preferred case by a microcontroller 17, which is provided with the external circuit shown schematically in FIG. The switch 15 is formed by a thyristor with upstream Graetz bridge 18. The thyristor is a load resistor 19 connected in series. The microcontroller 17 controls the thyristor at its gate.

From the voltage supplied by the Graetz bridge 18, a resistor 21 in conjunction with a Zener diode 22 branches off the operating voltage for the microcontroller 17. The Zener diode 22 may be connected in parallel with a buffer capacitor 23. The Zener diode 22 can also be replaced by a voltage regulator.

The microcontroller 17 is associated with a detection device 24 to detect short-term operating voltage dips, which can lead or lead to an inadvertent extinction of the gas discharge lamp. This detection device 24 supplies at operating voltage interruptions, which are bridged by the buffer capacitor 23, a short signal pulse to a corresponding input of the microcontroller 17 to signal to this that now a Wiederzündvorgang is pending. In the embodiment according to FIG. 4, 4a or 4b, the identification device 24 includes a Zener diode 25 connected to the Graetz bridge 18 and thus to the unfiltered operating voltage, whose other electrode (anode) is connected to the associated input of the microcontroller 17 is connected (dashed components are optional). In addition, a resistor 27 and optionally a capacitor 26 are connected to the latter, which are both connected to ground and thus in turn connected to the other end of the Graetz bridge 18. The Zener diode 25 can also be replaced by a resistor.

The microcontroller 17 is program-controlled. Its programming takes place in the language suitable for the specific type for performing the function described below.

The circuit of Figure 1 and the control circuit 12 of Figure 4 operate as follows:

Was the circuit for a long time disconnected from the mains, for example by no line voltage was applied to the line L, the control circuit 12 is in the idle state and the switch 15 is open (not current-conducting). If operating voltage is now applied (eg 220 V, 50 Hz sin), this is applied to the high-ohmic gas discharge lamp 1 via the ballast 2 and the ignition pulse transformer 4. In addition, the capacitor 5 is charged via the resistor 8 and the capacitor 9 until the breakdown voltage of the sidac 7 is reached. With breakthrough, this becomes low-resistance, so that the capacitor 5 discharges at the primary winding of the ignition pulse transformer 4. If the current drops below a holding value, the Sidac 7 again high impedance and the capacitor 5 is in turn recharged through the resistor 8 and the capacitor 9. This game can be repeated several times at each power half wave. The ignition pulse transformer therefore generates a train of ignition pulses. With a cold lamp, these usually lead immediately to the ignition of the gas discharge lamp 1. This ignites thus at the first half-wave or shortly thereafter. If the gas discharge lamp 1 burns, the voltage between the ballast 2 and the gas discharge lamp 1 drops so far that the capacitor 5 no longer reaches the breakdown voltage of the Sidacs 7. There are thus no more ignition pulses generated.

It may now happen that the operating voltage is interrupted for a short time or that it is superimposed on a glitch, which acts as a very short-term operating voltage interruption and brings the gas discharge lamp 1 to extinguish. During the time of the operating voltage interruption, the microcontroller 17 remains active. Although at the terminals 13, 14, the supply of the control circuit 12 can be omitted for a short time this is bridged by the buffer capacitor 23. However, the Zener diode 25 transmits the operational collapse or the other interfering pulse directly to the input of the microcontroller 17, so that the latter recognizes, in particular on the basis of the sudden increase in voltage between the terminals 13, 14, that the gas discharge lamp 1 has meanwhile been extinguished. He now performs the start of the gas discharge lamp 1 in the operating mode "warm ignition" or "Wiederzündbetriebsart" by. This begins with the closing of the switch 15 which thus becomes conductive. Thereby, the generation of ignition pulses is suppressed since the beginning t1 of the re-ignition for a predetermined time-of-waiting, for example, 12 seconds or even 24 seconds. After that, for example, ignition pulses can be generated for 12 seconds and applied to the gas discharge lamp 1. This interplay of pause and ignition test can now be repeated continuously until the gas discharge lamp 1 ignites.

Due to the delayed generation of ignition pulses in the Wiederzündbetriebsart the gas discharge lamp 1 is first Opportunity to cool something before any ignition attempts are made. This significantly increases the likelihood of immediate ignition at the first re-ignition attempt. Ignores the gas discharge lamp 1 but not immediately is avoided by the clocked application of ignition pulses of excessive energy input into the gas discharge lamp, which would otherwise lead to a slowdown of the cooling of the gas discharge lamp.

On the other hand, if the operating voltage is interrupted for a longer time, this recognizes the detection device 24 as well. During cold start, the capacitor 26 and the buffer capacitor 23 are empty. The sudden increase in voltage at the terminals 13, 14 is first visible to the capacitor 26 and thus to the corresponding control input of the microcontroller 17. Only then receives this with increasing voltage on the buffer capacitor 23 its operating voltage. The control pulse, which would put him in the Wiederzündbetriebsart is at this time already past and remains ineffective. As a result, the microcontroller 17 remains in its cold ignition mode and allows the immediate generation of ignition pulses.

In an improved embodiment, it is monitored, in particular in the Wiederzündbetriebsart, how long the unsuccessful delivery of ignition pulses to the gas discharge lamp 1 lasts. If these ignition tests exceed a time limit of, for example, five or ten minutes, it can be concluded that the ignitor 3 is connected to a gas discharge lamp that is difficult to re-ignite, such as, for example, a so-called ceramic burner lamp. In this case, the pauses between individual ignition attempts can then be extended, for example to 52 seconds or to 1 minute. On the other hand, the duration of the ignition attempts can be extended, for example to 24 seconds.

In a further modified embodiment, which differs from the embodiment described above by the programming of the microcontroller 17, the time from extinction of the lamp to successful re-ignition or alternatively the number of ignition attempts is monitored during hot ignition (re-ignition) and taken into account in the next Wiederzündvorgang ,

In a further possible modification, the number of Wiederzündversuche occurring in a given period in case of unintentional extinction of the gas discharge lamp 1 can be monitored and any new Wiederzündversuch be stopped if a given limit number is exceeded. This avoids that arrived at the end of life lamps that are prone to permanent re-extinction, are constantly re-ignited, which would cause unpleasant Blink effects.

FIG. 2 illustrates a modified embodiment of the circuit according to FIG. 1, wherein the same reference numerals are used for identical circuit parts, making use of the previous description. The embodiment of Figure 2 differs from that of Figure 1 by the arrangement of the control circuit 12 'in a lamp current-carrying path. The control circuit 12 'includes a switch 15', which is normally closed, while the switch 15 of Figure 1 is normally open. To interrupt the ignition operation of the gas discharge lamp 1, the switch 15 is opened. Otherwise, the circuit 16 'coincides with the circuit 16 Figures 1 and 4 match. Likewise, the functional description applies accordingly.

Figure 3 illustrates an embodiment of the circuit for the gas discharge lamp 1, which does not require Zündimpulstransformator. For this purpose, the ballast 2 is provided with a tap. This tap is connected via a capacitor 28, a triac 29 and an optional current limiting resistor 31 or alternatively a throttle to the reference potential N. The control electrode of the triac 19 is connected via a diac 32 to a voltage divider consisting of two resistors 33, 34, which taps off the lamp voltage. The resistor 34 is a phase shifter capacitor 35 connected in parallel.

The switch 15 serves to inhibit driving pulses of the Diacs 29 to prevent the generation of high voltage pulses. If it is open high voltage pulses are generated until the gas discharge lamp 1 ignites. If, on the other hand, it is closed, the generation of the ignition pulses is omitted. The circuit 16 opens and closes the switch 15 according to the diagrams 5 and 6 and the associated description.

Figure 3a illustrates a modified embodiment of the circuit for the gas discharge lamp 1, which does not require Zündimpulstransformator. Again, the ballast 2 is provided with a tap, which is connected via a capacitor 28, a triac 29 and an optional current limiting resistor 31 or alternatively a throttle to the reference potential N. The control circuit 16 described above is not used here to control a switch 15, the ignition pulses of the triac 29 shorts, but it controls the triac 29 directly. Should the generation of Lampenzündimpulsen it is connected to the phase shifter network consisting of the resistors 33, 34 and the capacitor 35 to generate the ignition pulses for the triac 29, if necessary. The detection of hot start situations is carried out as in the circuit of Figure 4 with the corresponding circuit parts are not specified here individually.

FIG. 5 illustrates the function of the microcontroller 17 as a block diagram. Its input 36 leads to a time filter 37, which examines incoming pulses to see if they arrive at a time interval greater than a minimum time. The time filter 37 serves to distinguish successive extinguishing of the high-pressure gas discharge lamp, which may occur as a repeated flash during the ignition thereof, from unintentional extinction, which may occur during quiet burning of the high-pressure gas discharge lamp 1 as a result of mains disturbances. The time filter 37 may be set to, for example, 1, 3 or 5 seconds. The specified by him minimum time, however, is significantly less than the blinking times occurring at the end of life of the high-pressure gas discharge lamp 1.

Parallel to the time filter 37, a cold-start detection device 38 is connected to the input 36, which serves to distinguish a cold start from a warm start. It compares, for example, the time ratio of the arrival of the operating voltage of the microcontroller 17 with the arrival of a signal at the input 36. If this signal arrives rather than the operating capacitor voltage delayed by the buffer capacitor 23, the cold-start detection device outputs 38 at its output 39 from a reset signal. This is routed to one of two alternative reset inputs 41, 42 of a count block 43. The count block 43 has a count input 44 which is connected to the output of the time filter 37. Its own output 45 leads to an input of an OR gate 46, whose output 47 forms the output of the microcontroller 17 and controls the gate of the thyristor 15. The other input of the OR gate 46 leads blocking pulses, which may originate from other unillustrated blocks of the microcontroller 17, for example, to interrupt the ignition operation.

The pulses conducted to the counting input 44 also pass to a timer circuit 48 which sets a critical burning time. The critical burning time may be set to, for example, one or two hours. The output of the timer circuit 48 is connected to the reset input 42. If the counter block 43 receives a signal at its reset input 41 or at its reset input 42, it is reset to its original value. At its output 45 it outputs a signal when it has received at its input 44 a predetermined number of counts without having been reset in the meantime.

The detection of the end of life of the high-pressure gas discharge lamp 1 and the suppression of power failures in the context of this recognition process works as follows:

In FIG. 6, the burning (B) or non-burning (N) of the gas discharge lamp 1 is illustrated as a time diagram. At time t0, the gas discharge lamp 1 is turned on cold. The count block 43 is thereby reset to its basic value, for example 3, as a result of an output signal of the cold-start detection device 38. Now go out at a time t1, the gas discharge lamp 1, for example, as a result of a network failure and this is timely, ie before the expiration of the critical burning time Z, the case of the count block 43 is decremented. He assumes the value 2. If, at a time t2, the gas discharge lamp 2 again disappears as a result of a system fault, again before the critical burning time Z has elapsed, the counting block 43 is again decremented. He then has the value 1. If then no extinguishment of the gas discharge lamp 1 more, the critical burning time Z expires and triggered by the last count timer circuit 48 then provides at its output at a time t3 a reset signal for the count block 43. He now has again the value 3. The gas discharge lamp 1 burns undisturbed. Alternatively, instead of completely resetting the counting block 43, counting in the opposite direction (incrementing) may also take place. It is also possible in such a case to increment by several steps x (n: = n + x)). The step number x may be a given constant or a variable determined from the history.

In the lower half of the diagram of FIG. 6, three successive deleting events at the times t4, t5 and t6 are illustrated, wherein none of the time intervals is longer than the critical burning time Z. Therefore, the erase event occurring at the time t6 sets the count block 43 to zero, whereby the signal appearing at the output of the count block 43 is output to the outside via the OR gate 46 as a signal for the switch 15 to close it and to further ignite the gas discharge lamp 1 prevention. If the counter has expired so far it can not be reset by the signal of the timer circuit 48. Its reset input 42 is so far underprivileged. He is when he is critical Count value has reached zero, only on a reset signal at the reset input 41 resettable.

An ignition method and an ignition device are proposed, in which the intervals between deletion events of a high-pressure gas discharge lamp 1 are monitored. The monitoring of burning or erasing is done by monitoring the burning voltage. Only a certain number of short-term successive deletion events are permitted. If the maximum number of deletion events is reached or exceeded consecutively in the short term, the ignitor or the gas discharge lamp is shut down. If this maximum number is not reached, an event counter is reset to its initial value or it is counted by one or more steps in the opposite direction (n + 1 or n + x).

Claims (12)

1. Ignition device (3) for high-pressure gas discharge lamps (1), in particular with electromagnetic ballast (2),
   with a controllable high-voltage generator (11), which is connected to the gas discharge lamp (1) to feed ignition pulses to this,
   with a control circuit (12), which is connected to the high-voltage generator (11) to control this and which can be operated in at least two different modes of operation,
   characterised by
   a cold-start recognition system (38) for distinguishing a cold start from a warm start, which is connected to the control circuit (12) or is a part thereof,
   a reset extinction counter (24), which is part of the control circuit (12) or is connected to this to count extinctions and/or ignitions of the gas discharge lamp (1) and to prevent further ignition attempts until the next cold start when a counter limit is reached,
   a timer (48), which defines the critical burning time, is triggered by an ignition of the gas discharge lamp (1) and is connected to the extinction counter (43) in order to reset this on expiry of its trigger time,
   whereby an in practice very secure differentiation is made between lamp extinctions occurring at the end of the service life and lamp extinctions occurring as a result of mains disturbances.
2. Ignition device according to Claim 1, characterised in that the extinction counter (43) has a filter circuit (37) connected in front of it to count extinction events following one another in short intervals or simply to count lamp ignitions.
3. Ignition device according to Claim 2, characterised in that the filter circuit (37) fades out extinction events or lamp ignitions, which occur at a time interval relative to one another such as that to be expected in an ignition process of an intact gas discharge lamp (1).
4. Ignition process for high-pressure gas discharge lamps (1) by means of an ignition device (3), characterised in that when the gas discharge lamp (1) is in operation the ignition device (3) monitors the number of re-ignition processes occurring in a given time window in order effect an in practice very secure differentiation between lamp extinctions occurring at the end of the service life and lamp extinctions occurring as a result of mains disturbances through monitoring of the adherence to a critical burning time or of this not being fallen short of multiple times in succession,
   wherein for this a critical burning time is defined and it is monitored: a) whether the high-pressure gas discharge lamp burns longer than this time, or b) whether it switches off within the critical burning time, wherein this is recorded and the recordings are counted to determine a counter value,
   wherein the high-pressure gas discharge lamp:

   in case a) is classed as operative and is operated further, and

   in case b) is classed as worn and is shut down when the counter value exceeds a given or alternatively also a pre-definable value,

   wherein additionally the high-pressure gas discharge lamp is blocked for further ignition attempts when a maximum number of re-ignition processes is exceeded.
5. Ignition process according to Claim 4, in which:

   when the gas discharge lamp (1) is in operation, the ignition device (3) counts the number of re-ignition processes with a counter (43), wherein counting only proceeds by adding one when a time shorter than a minimum time has elapsed since the last re-ignition process,

   the counter (43) counts in the opposite direction in single or multiple stages or is reset when a burning time that is longer than a critical burning time has been reached since the last re-ignition process, and

   the ignition device is blocked for further ignition attempts when the counter reaches a given or pre-definable counter value.
6. Ignition process according to Claim 5, characterised in that the minimum time is equal to the critical burning time.
7. Ignition process according to Claim 5, characterised in that the re-ignition process is only counted when the time interval from the last re-ignition process is greater than a lowest time.
8. Ignition process according to Claim 7, characterised in that the lowest time is substantially lower than both the minimum time and the critical burning time.
9. Ignition process according to Claim 5, characterised in that the high-voltage pulses supplied by the ignition device (11) are supplied in a time cycled manner.
10. Ignition process according to Claim 4, characterised in that in the case of a re-ignition process the control circuit (12) records the re-ignition time which has passed from the start of re-ignition to actual ignition, and takes into consideration a waiting time in the next re-ignition process.
11. Ignition process according to Claim 10, characterised in that the waiting time is determined on the basis of the re-ignition time.
12. Ignition process according to Claim 14?, characterised in that in a re-ignition process the control circuit (12) records the number of ignition attempts, which are undertaken from the start of re-ignition to actual ignition, and takes into consideration a waiting time in the next re-ignition process, which is determined on the basis of the number of previous ignition attempts.

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