EP1425943B1 - Method and device for operating a fluorescent tube in an energy saving manner - Google Patents

Abstract

The invention relates to an energy-saving operating method and an apparatus for energy-saving operation of a fluorescent tube, especially a T5 fluorescent tube. In a first operating mode, heat current is applied to an incandescent filament at one end of the fluorescent tube. Moreover, in the first operating mode, another heat current is applied to another incandescent filament at an end of the fluorescent tube opposite to said one end. The other incandescent filament is connected to energy-saving circuitry. In a second operating mode, the application of the heat current to the incandescent filament and of the other heat current and the other incandescent filament is interrupted. Monitoring means are provided, which are comprised by electronic circuitry, to monitor an operating parameter of the other incandescent filament in the first and second operating modes. The electronic circuitry controls a time period of application of the other heat current to the other incandescent filament in dependence on a time period of application of the heat current to the incandescent filament, in response to the operating parameter being monitored.

Description

The invention relates to a method and a device for energy-saving operation of a fluorescent tube, in particular a T5 fluorescent tube.

Today T5 fluorescent tubes are often operated in T8 fluorescent tube sockets, so that existing lamp sockets for the older T8 fluorescent tubes for the modern T5 fluorescent tubes are used. In this case, a first adapter adapter is arranged at a first end of the T5 fluorescent tube and a second adapter adapter at a second end of the T5 fluorescent tube in order to compensate for a difference in length of the T5 fluorescent tubes which are shorter in comparison to the T8 fluorescent tubes. At the second adapter adapter, an electronic ballast (EVG) is arranged to operate the fluorescent tube energy-saving. For this purpose, the ECG generates a high-frequency voltage and controls the switching on and off of a heating current for preheating arranged at the two ends of the T5 fluorescent tube filaments before the ignition of the T5 fluorescent tube and in dimming mode. For optimized operation of the T5 fluorescent tube, it is necessary that the filaments on both sides of the T5 fluorescent tube are simultaneously supplied with a heating current. An electronic circuitry disposed on the second adapter interface controls the heating power supply of the filament to the first end of the T5 fluorescent tube. At the second end, this task takes over the TOE.

From the international patent application WO-A-02/067290 (published on 29/08/2002 ) is known for the synchronized switching on and off of the heating current on both sides of the T5 fluorescent tube from the ECG to the electronic circuitry, a signal optically, especially in the infrared spectral range, or to transmit by means of an additional signal line. The disadvantage of optical signal transmission is that the light path can be disturbed, for example, by dust or particles. The use of an additional line requires that it be routed, which causes additional costs and thus also disadvantageous.

From the WO-A-00/21342 a circuit arrangement for energy-efficient operation of a fluorescent tube is known, which has a ballast (throttle) and an electronic circuit arrangement. However, the ballast and the electronic circuitry are connected together. Furthermore, from the EP-A-391,360 a single ballast for a direct-heated discharge lamp is known, which is connected to two filaments. Of the DE-A-4 303 595 a circuit arrangement for operating a fluorescent lamp is known which has electrodes. Each electrode is connected to both an electronic ballast and a resonant circuit.

The object of the invention is to provide an improved method and an improved apparatus for energy-efficient operation of a fluorescent tube, in particular a T5 fluorescent tube, that (that) allows independent of unfavorable environmental influences control of the heating current to the incandescent filament of the fluorescent tube.

This object is achieved by a method according to the independent claims 1 and devices according to independent claim 5.

The invention comprises as essential thought a monitoring of an operating parameter of the filament at one end of the fluorescent tube, which is formed with respect to another of the fluorescent tube. At the other end of the fluorescent tube, an energy saving device (ECG) is arranged. The monitoring of the operating parameter is carried out with the aid of monitoring means of an electronic circuit arrangement, the electronic circuit arrangement controlling the switching off / on of the heating current for the incandescent filament at one end as a function of the monitored operating parameter. Between the electronic circuit arrangement and the energy saving device no signals are exchanged by means of an optical transmission path or a signal line, as provided in the prior art. In this way it is prevented that conditions in the operation of the fluorescent tube, which may hinder the signal transmission between the energy-saving device and the electronic circuitry, influence the automatic control of the application of the filament to the one end with heating current. This makes it possible that the fluorescent tubes can be reliably operated energy-saving even under operating conditions, for example, arise when moisture or dirt lead to deposits on the fluorescent tube or the associated components, which hinders an optical signal transmission. The application possibilities of the energy saving devices are thus extended.

With the help of monitoring the operating parameter of the incandescent filament, which is not coupled to the energy saving device, the times of switching on / off of the heating currents to the filament and the duration of exposure of the filament to the heating current with the Heizstrombeaufschlagung the filament, which at the Energy-saving device is coupled, synchronized. As a result, the application of the two filaments to the respective heating current can either be shifted in time relative to one another or executed at the same time, which applies both to the switching on and the switching off of the heating current.

As an operating parameter, which is monitored by means of monitoring means of the electronic circuit arrangement, in particular a frequency-dependent burning voltage at the further filament is suitable, which is not coupled to the ECG.

Conveniently, the frequency-dependent burning voltage can be used to induce in a resonant circuit a frequency-dependent voltage, which is used as an indicator of the need for switching on / off of the heating current for the filament. When the fluorescent tube is operated in a dimming operation, the frequency of the burning voltage changes at the filament not coupled to the ECG. This frequency change and the resulting induced voltage in the resonant circuit is used as a control signal for a change in the application of the filament to the heating current. The separately formed electronic ballast of the ECG, which is coupled to the filament, is designed so that the control of the heating current to the filament takes place automatically in dependence on the monitored operating parameters.

The method and apparatus, in which an operating parameter of the incandescent filament is used as a starting point for controlling the Heizstrombeaufschlagung the filament can be used appropriately for energy-saving operation of a T5 fluorescent tube. When T5 fluorescent tubes are used in a lampholder originally intended for another model of fluorescent tube, such as a T8 bulb, the ballast and / or electronic circuitry can be incorporated into adapters used to hold the T5 bulb in place serve the conventional version.

Figur 1

eine Anordnung zum energiesparenden Betreiben einer T5-Leuchtstoffröhre in zwei T8-Leuchtstoffröhrenfassungen; (gehört nicht zur Erfindung; dient dem Verständnis),

Figur 2

eine elektronische Schaltungsanordnung zum Steuern des Heizstroms einer Glühwendel an dem vom EVG abgewandten Ende einer T5-Leuchtstoffröhre bei der Anordnung nach Figur 1; (gehört nicht zur Erfindung; dient dem Verstandnis),

Figur 3

eine weitere Anordnung zum energiesparenden Betreiben einer T5-Leuchtstoffröhre in zwei T8-Leuchtstoffröhrenfassungen; und

Figur 4

eine elektronische Schaltungsanordnung zum Steuern des Heizstroms einer Glühwendel an dem vom EVG abgewandten Ende einer T5-Leuchtstoffröhre bei der weiteren Anordnung nach Figur 3.

The invention will be explained below with reference to an embodiment with reference to a drawing. Hereby show:

FIG. 1

an arrangement for power-saving operation of a T5 fluorescent tube in two T8 fluorescent tube holders; (does not belong to the invention, serves the understanding),

FIG. 2

an electronic circuit arrangement for controlling the heating current of a filament at the end remote from the ECG of a T5 fluorescent tube in the arrangement according to FIG. 1 ; (does not belong to the invention, serves the understanding),

FIG. 3

another arrangement for energy-saving operation of a T5 fluorescent tube in two T8 fluorescent tube holders; and

FIG. 4

an electronic circuit arrangement for controlling the heating current of a filament at the end remote from the ECG of a T5 fluorescent tube in the further arrangement according to FIG. 3 ,

FIG. 1 shows an arrangement for operating a modern T5 fluorescent tube 1 in a first T8-Leuchtwwstrrhrenfassung 2 and a second T8 fluorescent tube socket 3. Die First and second T8 fluorescent tube holder 2, 3 each have two receptacles 4, 5 and 6, 7. Between a first end 8 of the T5 fluorescent tube 1 and the first T8 fluorescent tube holder 2, a first intermediate adapter 9 is arranged. Between a second end 10 of the T5 fluorescent tube 1 and the second T8 fluorescent tube holder 3, a second intermediate adapter 11 is arranged. Terminal pins 12 and 13 of the first intermediate adapter 9 are electrically connected to the receptacles 4 and 5 of the first T8 fluorescent tube holder 2. Accordingly, pins 14 and 15 of the second intermediate adapter 11 are electrically connected to the receptacles 6 and 7 of the second T8 fluorescent tube holder 3. At the second intermediate adapter 11, an electronic ballast 16 is arranged. Two connecting cables 17 and 18 connect a first connector 19 and a second connector 20 of the electronic ballast 16 with the pins 14 and 15 of the second intermediate adapter 11. In this way, the electronic ballast 16 is supplied with electrical voltage. The electronic ballast 16 includes a plurality of electronic components 21, 22 and 23, the concrete execution of which can be selected by a person skilled in the art depending on the application for the energy-saving operation of the fluorescent tube for a known as such electronic ballast. The electronic ballast 16 generates a high frequency signal, which is forwarded via a third connector 24 and a fourth connector 25 by means of two leads 26 and 27 to receiving sockets 28 and 29 of the second adapter adapter 11. Via contact pins 30 and 31 of the second end 10 of the T5 fluorescent tube 1, which are arranged in the receiving sockets 28 and 29, a first filament 32 is electrically connected to the high-frequency signal. A second filament 33 at the first end 8 of the T5 fluorescent tube 1 is connected via contact pins 34 and 35 and corresponding receptacles 36 and 37 of the first adapter adapter 9 with an electronic circuit 38. The electronic circuitry 38 is also connected to the connection pins 12 and 13 of the first T8 fluorescent tube socket 2. For a warm start of the T5 fluorescent tube 1 and for a smooth dimming operation of the T5 fluorescent tube 1, it is necessary that the first filament 32 and the second filament 33 are heated. In undimmed continuous operation, however, it is necessary that the first filament 32 and the second filament 33 are not heated. In order to achieve a simultaneous heating of the first filaments 32 and the second filament 33, a signal is transmitted to a light-sensitive diode 40, for example by means of an infrared light emitting diode 39, by means of which the electronic circuit 38 is caused to heat the second filament 33 or to set the heating mode ,

FIG. 2 shows an embodiment for the electronic circuitry 38. Same features are denoted by the same reference numerals as in FIG FIG. 1 Mistake. At connecting pins 12 and 13, a system voltage applied to the receptacles 4 and 5 of the T8 fluorescent tube holder 2, the electronic circuitry 38 is supplied (see. FIG. 1 ). This is usually 220V AC power supply.

The second filament 33, which is conductively connected to the terminals 36 and 37, is supplied via two counter-wound half coils 41 and 42 heating current. Due to the opposite winding directions of the half coils 41 and 42 of the heating current of the filament 33 (in FIG. 2 not shown) in a second coil 43 no voltage induced. Only the high-frequency lamp filament current flowing through one of the two half-coils induces a voltage in the second coil 43. The high-frequency lamp current flows only via one of the two terminals 12 or 13 from / to. The voltage induced in the second coil 43 is rectified by means of a diode 44. The induced rectified voltage charges a charging capacitor 45. A resistor 46 and a capacitor 47 constitute a sieve member.

A voltage difference occurring between point 48 and point 49 of the circuit is represented by a voltage across a resistor 50 and a photosensitive photodiode 51 (identical to the photosensitive diode 40 in FIG Figur1 ), and depends on the incidence of light on the photodiode 51. The voltage difference between the points 48 and 49 is identical to the voltage difference between a gate and a source of a field effect transistor 52. The field effect transistor 52 is a self-locking end channel field effect transistor, which is mounted thermally conductively. This turns on fully at a voltage difference of about +5 V between gate and source. In the through-connected state, the second incandescent filament 33 (in FIG FIG. 2 not shown) between the terminals 36 and 37 shorted. Zener diodes 54 and 55 and a resistor 56 serve as a voltage limiter. A resistor 57 serves to establish an operating point of the field effect transistor 52. A light-emitting diode 58 with a series resistor 59 provides optical information as to whether the circuit is operating correctly. A fuse 60 arranged near the field effect transistor 52 interrupts the current supply in the event of overheating of the field effect transistor 52, so that a thermal fuse is provided.

FIG. 3 shows a further arrangement for energy-saving operation of a T5 fluorescent tube, in contrast to the arrangement according to FIG. 1 between the arranged on the first adapter adapter 9 electronic circuitry 38 and arranged on the second adapter adapter 11 electronic ballast 16 no optical signal transmission path is formed. The task of the electronic circuit 38 in the first adapter adapter 9 to supply the second heating coil 33 of the T5 fluorescent tube 1 in case of need with a heating current is met by an electronic circuit arrangement, for which in FIG. 4 an embodiment is shown.

FIG. 4 shows an embodiment of the for use in the arrangement according to FIG. 3 provided electronic circuitry 38 in detail. Same reference numerals in the FIGS. 4 and 2 denote the same characteristics. According to FIG. 4 a capacitor 61 is arranged parallel to the second coil 43. As a result, a parallel resonant circuit is formed, which is tuned so that between a point 62 and a point 63, a maximum voltage amplitude occurs at the high frequency of the lamp current at which the T5 fluorescent tube 1 generates a maximum amount of light. In dimming mode, the frequency for operating the t5 fluorescent tube is further increased. In such a case, the voltage amplitude occurring between the points 62 and 63 decreases. This voltage amplitude affects the voltage difference between the gate and source of the field effect transistor 52. The parallel resonant circuit formed by the second coil 43 and the capacitor 61 thus replaces the function of the photosensitive photodiode 51 of the circuit FIG. 2 , In addition, the electronic circuitry of the FIG. 4 Diodes 64 and 65, which prevent flow back. Otherwise, the operation of the electronic circuitry of the FIG. 4 identical to the above FIG. 2 described electronic circuitry.

When the fluorescent tube is switched on, no high-frequency signal is present at the inputs of the T8 fluorescent tube socket. A low frequency current (50 Hz mains current) flows through the half coils 41 and 42 and the second filament 33, which is connected to the terminals 36 and 37. After the T5 fluorescent tube has ignited, a high-frequency current flows through one of the two half-coils 41, 42. As a result, a voltage is induced in the parallel resonant circuit formed by the coil 43 and the capacitor 61. The charging capacitor 45 is charged, and the voltage applied to the charging capacitor 45 Voltage is smoothed by means of the resistor 46 and the capacitor 47. The capacitor 47 also serves for time delay.

The voltage induced in the parallel resonance circuit causes a positive voltage difference between the gate and the source of the field effect transistor 52. As a result, the field effect transistor 52 is turned on and closes via the bridge rectifier 53, the second filament 33 (in FIG. 4 not shown) between the terminals 36 and 37 short. In the switched-through state of the field effect transistor 52, therefore, no heating current flows through the second filament 33 connected to the terminals 36 and 37.

In dimming mode, the frequency with which the T5 fluorescent tube is operated is increased. This reduces the voltage induced in the resonant circuit. A decrease in the induced voltage at the same time causes a reduction in the voltage difference between the gate and the source of the field effect transistor 52. If the voltage difference between the gate and source decreases, the field effect transistor 52 begins to block. In this case, the second filament 33 (in FIG FIG. 4 not shown) is no longer short-circuited via the bridge rectifier 53, so that again a heating current through the connected to the terminals 36 and 37 second filament 33 can flow. The branch with the field effect transistor can be assigned a resistance value which is of the order of the resistance value of the incandescent filament. Thus, part of the current flows through the FET and part through the filament. The heating current flowing through the second incandescent filament 33 is thus inversely proportional to the current flowing through the field effect transistor 52.

Claims (7)

1. Method for energy-saving operation of a fluorescent tube (1), in particular of a T5 fluorescent tube, wherein the method comprises the following steps:

   - Supplying an incandescent helical filament (32) at one end of the fluorescent tube (1) with a filament current in a first mode of operation, wherein the incandescent helical filament (32) is connected to an electronic energy-saving circuit arrangement (16);

   - Supplying a further incandescent helical filament (33) at an end of the fluorescent tube (1) opposite said end with a further filament current, wherein the further incandescent helical filament (33) is connected to an electronic circuit arrangement (38) which is separate from the electronic energy-saving circuit arrangement (16); wherein the further incandescent helical filament (33) can be supplied with filament current at a different time to the incandescent helical filament (32) or simultaneously, and

   - Interrupting the supply of the incandescent helical filament (32) and of the further incandescent helical filament (33) with the filament current or the further filament current in a second mode of operation;

   wherein, with the help of monitoring means which are encompassed by the electronic circuit arrangement (38), an operating parameter of the further incandescent helical filament (33), which indicates the presence of a current, is monitored in the first and the second mode of operation, in order, with the help of the electronic circuit arrangement (38), as a function of the monitored operating parameter, to control a period of time for supplying the further incandescent helical filament (33) with the further filament current as a function of a period of time for supplying the incandescent helical filament (32) with the filament current.
2. Method according to Claim 1, characterised in that a frequency-dependent burning voltage at the further incandescent helical filament (33) is monitored as an operating parameter of the further incandescent helical filament (33).
3. Method according to Claim 2, characterised in that a frequency-dependent voltage induced in a resonant circuit (43, 61) is used for monitoring of the frequency of the burning voltage.
4. Method according to one of the preceding claims, characterised in that the fluorescent tube (1) is operated in a dimming mode in the first mode of operation.
5. Device for energy-saving operation of a fluorescent tube (1), in particular of a T5 fluorescent tube, with:

   - an electronic energy-saving circuit arrangement (16) which can be coupled to the incandescent helical filament (32) for control of a supply of an incandescent helical filament (32) at one end of the fluorescent tube (1) with a filament current; and

   - an electronic circuit arrangement (38) which is separate from the electronic energy-saving circuit arrangement (16) and which can be coupled to the further incandescent helical filament (33) for control of a supply of a further incandescent helical filament (33) at an end of the fluorescent tube (1) opposite to said end with a further filament current; wherein the further incandescent helical filament (33) can be supplied with filament current at a different time to the incandescent helical filament (32) or simultaneously, and

   wherein the electronic circuit arrangement (38) has monitoring means in order to monitor an operating parameter of the further incandescent helical filament (33), which indicates the presence of a current, so that, with the help of the electronic circuit arrangement (38), as a function of the monitored operating parameter, an activation/deactivation of the supply of the further incandescent helical filament (33) with the further filament current can be controlled as a function of an activation/de-activation of the supply of the incandescent helical filament (32) with the filament current.
6. Device according to Claim 5, characterised in that the monitoring means have means for monitoring a frequency of a burning voltage which is present at the further incandescent helical filament (33).
7. Device according to Claim 6, characterised in that the means for monitoring the frequency of the burning voltage which is present at the further incandescent helical filament have a resonant circuit (43, 16).

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