WO2010000349A1 - Detecting the type of a gas discharge lamp connected to an operational device - Google Patents

Abstract

The invention relates to detecting a lamp type and setting of operating parameters for operating luminous elements depending on the type of luminous element detected, comprising the following steps: Constant regulating of the power fed to the luminous element, - detecting the voltage drop across the burning luminous element at constant power or the current flowing through the luminous element, and - selecting at least one operating parameter as a function of the voltage drop.

Description

 Detection of the type of a gas discharge lamp connected to an operating device

The invention relates generally to the field of control gear for lighting and more precisely to control gear to which permissible different types of lamps are connected, wherein the operating device then in the same burning process or for a subsequent burning - without human involvement - automatically operating parameters to match the actually present Lamp type is set. This process is called "lamp type detection" in the following.

From EP-A-0 413 991 it is known to determine the ignition voltage of the connected gas discharge lamp and to close the lamp type on the basis of the determined ignition voltage. However, the determination of the ignition voltage depends inter alia on the manufacturer, the degree of aging, the gas filling and the heating of the lamp, so that overall fluctuations in the range between 10% and 20% can result in determining the ignition voltage.

From EP 702508A1 it is known to specify different lamp current setpoints after the gas discharge lamp has been put into operation and to set the lamp current according to these set values. For each lamp current setpoint, the corresponding actual value of the operating variable of the gas discharge lamp to be monitored is determined. The individual actual values of the operating variables thus obtained are combined with each other, so that subsequently, on the basis of the actual values, they depend on the given values Lamp current setpoints on the lamp type of the connected gas discharge lamp can be closed. For this purpose, for example, the evaluation of different predetermined characteristics of the individual lamp types is conceivable. For example, the current / voltage characteristics of different lamp types can be known. As described above, different current setpoints are set and the lamp voltage is determined as a function of the set current setpoint values. Based on the determined current / voltage value pairs and the various existing current / voltage characteristics, it is possible to deduce the lamp type of the connected gas discharge lamp. In particular, it is provided to determine the lamp voltage (Uist) or the helical resistance (Rist) of the gas discharge lamp as the operating variable for the lamp type detection.

If the lamp type of the connected gas discharge lamp has been detected, then this is preferably in one

Memory stored in the form of various operating parameters or in the form of the corresponding lamp characteristic, so that the lamp type does not need to be constantly checked and determined, as long as the corresponding gas discharge lamp has not been replaced. Replacing the lamp can be determined by detecting a possible interruption of the heating circuit.

From DE 198 50 441 Al a ballast for operating a lamp provided with a fluorescent lamp is known, wherein the operating data of certain recognizable with this method lamp types, at least their nominal lamp voltage and the lamp current, are stored in a register, the fluorescent lamp within a starting phase is operated for a predetermined time with a dimming current of known current strength, after the start phase, the present lamp voltage of the fluorescent lamp is measured, then in the register that lamp voltage is called which comes closest to the measured lamp voltage of the fluorescent lamp, and then the to the operation of the Fluorescent lamp required operating data are assigned to the measured lamp voltage per register.

In the case of a lamp type detection based on helical parameters (for example, their ohmic resistance), there is the disadvantage that this does not always result in a clear lamp identification. The reason for this is that with a uniform lamp type, on the one hand, the ohmic resistance of a filament can fluctuate, for example, by up to 25% and, at the same time, the filament resistance of different lamp types can be approximately of this order of magnitude. In addition, basically different types of lamps can have the same coil resistance.

With regard to the mentioned DE 198 50 441 A1 and EP 702508 A1, it should be noted that the methods used there have several disadvantages. The disadvantage of a lamp type detection based on the setting of a current is that a large part of the possible lamp types can not be identified or distinguished by this method. Due to the lamp characteristics, an approximately equal lamp burning voltage can result for different lamp types with an impressed current as a function of the ambient temperature, which can not be distinguished under consideration of the manufacturer tolerances. If the environment or Lamp temperature is not known, this method is suitable only for a very limited temperature range.

To give the user the widest possible

Allow ambient temperature range, without losing one

To perform temperature measurement, therefore, the inventive method is proposed.

This object is solved by the features of the independent claims. The dependent claims further form the central idea of the invention in a particularly advantageous manner.

A first aspect of the invention relates to a method for lamp type detection and setting of operating parameters for the operation of light sources as a function of the recognized type of light source, the method comprising the following steps: constant control of the power supplied to the light source,

Detecting the voltage drop occurring at constant power across the burning lamp or the current flowing through the lamp, and selecting at least one operating parameter depending on the voltage drop or the lamp current.

The light sources can be supplied with an AC voltage starting from an inverter supplied with a constant DC voltage.

The constant regulation of the luminous flux can be achieved by taking into account the current through a potential lower Switch of two series-connected switches of the inverter done.

As the inverter, a half-bridge circuit with two series-connected and alternately clocked switches can be used.

As light source one or more gas discharge lamps can be used.

The Lampentyperkennung can be done without measuring the current through the bulb.

The above-explained lamp type detection may be preceded by a lamp type pre-classification, in which the connected light source is pre-classified, for example, based on heating coil parameters of a gas discharge lamp.

The voltage drop at the light source can be detected by means of a voltage divider led to ground from the higher side of the light source.

Based on the voltage drop can be detected by a control unit, whether one or more lamps are connected in series connected to the operating device.

For lamp type detection, the current through the luminous means can be detected at a constant regulated power and a control unit can detect from the current through the luminous means whether one or more lamps connected in parallel are supplied by the operating device. The lighting means can be supplied from an inverter controlled by the control unit, which is supplied with a constant or constant regulated DC voltage, the control unit using the duty factor and / or the frequency of the inverter as the control variable for the power variable.

The invention also relates to an integrated control circuit, in particular ASIC, in support of a method of the type described above. The control circuit may be implemented digitally, wherein preferably all feedback or measurement signals are A / D converted before being further processed.

Furthermore, the invention relates to a control device for lighting means having such a control circuit, as well as to a lamp with such a control gear.

1 shows a schematic circuit diagram of a circuit according to the invention for operating a lamp Ri with lamp type detection, and

FIG. 2 shows signals as they appear on the circuit of FIG.

FIG. 1 shows a circuit for operating light-emitting means, wherein the light-emitting means are represented schematically by an ohmic resistor Ri.

Starting from a mains voltage, a rectifier GR is supplied, so that the rectified mains voltage of a Smoothing circuit PFC can be supplied. A preferably integrated and / or digital control circuit, for example an ASIC, a microcontroller or a hybrid solution thereof, which bears the reference character "C", can, for example, clock a switch of the smoothing circuit PFC and remove one or more measuring signals from the region of the PFC charges an energy storage element Kl, for example, a capacitor such as an electrolytic capacitor, so that this energy storage element Kl a stabilized DC voltage sets U _z. with this voltage U _2, often also called bus voltage or intermediate-circuit voltage, is an inverter with switches Sl and S2, which are connected in series, the switches S1 and S2 thus form a half-bridge inverter, or, of course, a full-bridge inverter may alternatively be provided.

At the midpoint of the two switches Sl, S2 attacks a load circuit, which has the lighting means Ri. More precisely, the load circuit has a series resonant circuit with a coil L and a capacitor Cl and an AC coupling capacitor C2, from which again the light sources R ₁ provided in parallel with the resonance capacitor C _{1 are} connected. With Wl and W2 schematically designed as heating coils electrodes of the lamps are shown, as they are typical for example for gas discharge lamps. Schematically, these coils W1 and W2 are shown in more detail as a combination of an ohmic resistance and an inductance LH. For heating, a heating circuit is provided, which is provided in parallel to the lower-potential switch S2 of the inverter WR and which has a capacitor C3, a Primärheizkreiswicklung LH 'and a switch S3, which can also be clocked by the control unit C. Transformatorisch so the heat output from the primary winding LH 'on the heating coils LH, Wl, W2 transferred.

In series with the potential-lower switch S2 of the inverter WR, a measuring resistor (shunt) SH is connected, at which a signal can be tapped, which reproduces the current through the potential-lower switch S2 of the inverter (if it is closed). More specifically, this signal I _H is used to charge a capacitor C4, which serves as an example of an implementation of an integration of the current I _H. The charging voltage of the capacitor C4 is supplied to the control unit C as a signal representing the load circuit provided power P _A. On the basis of the known (measured) value of the intermediate circuit voltage U _z together with the current value P _H integrated over several switching periods of the inverter WR, the control unit C can determine the actual power supplied to the load circuit.

According to the invention, a power control is now performed, in which this actual power value is compared with a desired power value, which is specified internally or externally. This target power value can be specified externally, for example to achieve dimming. The control variable for the power control is the switching frequency and / or the duty cycle of the switches Sl, S2 of the inverter WR, in particular in Interaction with the resonance curve of the series resonant circuit L, Cl.

According to the invention, an ohmic voltage divider R1, R2 can be provided parallel to the light-emitting means Ri, at which a signal Ui can be tapped and supplied to the control unit C, whereby this signal Ui can determine the voltage drop across the light-emitting means.

Alternatively or additionally, a further measuring resistor R3 may be provided, at which a signal Ii can be tapped off and supplied to the control unit C, this signal Ii reproducing the current through the lighting means Ri.

If the lighting means consist of a series connection of a plurality of light sources, the voltage divider Rl, R2 is designed such that the signal representing the light source voltage Ui reproduces the entire voltage attack via all series-connected bulbs.

If a plurality of lighting means Ri are connected in parallel, the measuring resistor (shunt) R3 is arranged such that the luminous flux signal Il reproduces the total current through all the luminous means Ri connected in parallel.

According to the invention, therefore, a multi-lamp device is provided which performs a lamp power control during the lamp type detection. This is done as explained above preferably characterized in that at constant regulated DC link voltage, the current at the shunt in series with the lower-potential switch of the Inverter (in the present case half-bridge circuit) is measured. From the product of the intermediate circuit voltage with this current (and further multiplied by a calibration factor, which is at symmetrical timing of the inverter = 2) can thus be determined, the lamp power.

The regulation of the lamp power can thus on the

Control variable 'frequency' or 'duty cycle' of the inverter and additionally or alternatively done via the regulation of the DC link voltage.

For the actual lamp type detection so the lamp current measurement is not used. Rather, at the specified target power, the lamp voltage setting at the lamp is measured and, starting therefrom, for example by comparison with a look-up table, a lamp type detection is carried out in such a way that operating parameters (for example for preheating, ignition operation and / or combustion operation) adapted for the 'recognized' lamp type, that is, depending on the self-adjusting lamp voltage, are selected. This is done by the preferably integrated control unit C.

The lamp type detection according to the invention, ie with the parameter lamp voltage at constant regulated and predetermined lamp power can also be used as one of several stages, in particular the second stage of a multi-stage lamp type detection method. For example, the first stage may be a helix parameter detection that performs some kind of preselection of the candidate lamp types. The fact that the voltage divider Rl, R2 is guided by the 'hot filament' to ground for Brennspannungserfassung, can be based on the Brennspannungsmessung also (ie beyond the lamp type detection) recognize whether one or more lamps are connected in series.

Instead of the relatively easy to detect lamp burning voltage can - again at a given and constantly controlled lamp power - and the lamp current can be measured and thus a Lampentyperkennung with kontant regulated lamp luminous power based on the measured lamp current.

In addition, it can be determined via the lamp current measurement based on the total current, whether one or more lamps are connected in parallel, which are powered by a common inverter from.

Thus, while in a series connection of two lamps, the burning voltage will double, the measured total current doubles in the parallel connection of two similar lamps.

According to the invention, of course, a lamp voltage measurement can be combined with the lamp current measurement, as I said always with constant regulated lamp power. In Figure 2, the course of the

Inverter shunt signal I _H and see the laterally averaged (or integrated) power signal P _A , which adjusts as a voltage across the capacitor C4.

Claims

Claims : 1. A method for lamp type detection and setting of operating parameters for the operation of lamps depending on the detected type of lamp, comprising the following steps: Constant regulation of the power supplied to the lamp, - Detection of adjusting itself at a constant power over the burning light source Voltage drop or the current flowing through the bulb, and - Choice of at least one operating parameter depending on the voltage drop or lamp current. 2. The method of claim 1, wherein the lighting means are supplied from an inverter supplied with a constant DC voltage with an AC voltage. 3. The method of claim 2, wherein the constant regulation of the lamp power takes place, including the current through a potential-lower switch of two series-connected switches of the inverter. 4. The method of claim 2 or 3, wherein as the inverter, a half-bridge circuit with two series-connected and alternately clocked switches is used. 5. The method according to claim any one of the preceding claims, wherein one or more gas discharge lamps are used as the light source. 6. The method according to any one of the preceding claims, wherein the current is not used by the lamp for Lampentyperkennung. 7. The method according to any one of the preceding claims, wherein the Lampentyperkennung is preceded by a lamp type Vorklassifizierung, in which the connected lamp is, for example, pre-classified by Heizwendeparametern a gas discharge lamp. 8. The method according to any one of the preceding claims, wherein the voltage drop across the lamp is detected by means of a guided from the higher side of the lamp to ground voltage divider. 9. The method of claim 8, wherein the basis of the voltage drop is detected whether one or more lamps are connected in series connected to the operating device. 10. The method of claim 1, wherein the current is detected by the light source for lamp type detection at a constant regulated power and is detected by the current through the light source, whether one or several lamps connected in parallel are supplied by the operating device. 11. The method according to any one of the preceding claims, wherein the lighting means starting from a Inverter supplied with constant or constant regulated DC voltage, and the duty cycle and / or the frequency of the inverter is used as a control variable for the power variable. 12. Integrated control circuit, in particular ASIC, which is designed to support a method according to one of the preceding claims. 13. Integrated control circuit according to claim 12, which is designed as a digital circuit. 14. operating device for lighting means, comprising a control circuit according to claim 12 or 13. 15. luminaire, comprising a luminous means and a control device according to claim 14.