DE20312298U1 - Electronic starter circuit for gas discharge lighting tubes has facility to change parameter operating data using link from external unit to flash memory - Google Patents

Abstract

The system has a starter circuit [100] that is connected to an external communication unit [200]. The tube [117]] is operated by switching transistors [114,115] coupled to a clock frequency generator [125]. This receives commands from a processor [121] using programme data held in ROM memory [122a]. Parameter data is exchanged with the external unit using a flash memory.

Description

Electronic ballast with writable parameter memory and associated communication device

The invention relates to an electronic ballast for operating a gas discharge lamp according to the preamble of claim 1 and an associated communication device.

The use of electronic ballasts (EVGs) when operating gas discharge lamps, particularly low-pressure gas discharge lamps, has the advantage that electrical energy can be saved, and at the same time the lamp efficiency is increased, so the use of such electronic ballasts is widespread. These work with a high-frequency generator to generate currents in the 0 frequency range above 10 kHz in order to achieve the aforementioned advantages when operating such a lamp. The ballast comprises a control device which controls the high-frequency generator in a manner adapted and optimized for the respective lamp. Accordingly, the ballast must be set to the operating parameters of the various operating phases, such as preheating, ignition and normal operation (lamp operation). For this purpose, an electronic ballast often has a memory in which the respective operating parameters are stored.

Electronic ballasts are also known in the field, which are designed to recognise the lamp type connected to the ballast. All lamp types that can be operated with the ballast are stored in the operating data register with the respective operating data, so that after lamp recognition, a lamp can be operated with the operating parameters optimised for it.

Such a ballast or a method for operating it is disclosed, for example, in European patent specification EP 1 125 477.

The invention is based on the object of providing an electronic ballast that offers even greater flexibility for operation with different lamps.

This object is achieved in a surprisingly simple manner by the invention with an electronic ballast having the features of claim 1 or an associated external communication device having the features of claim 6.

The electronic ballast according to the invention has a connection device with which a supply voltage can be applied to the ballast and an inverter connected to the input side of the connection device for generating a high-frequency inverter controlled by a control device for supplying the gas discharge lamp. A choke is connected to the output of the inverter, and the lamp can be connected in series with the choke to limit the lamp current. In order to provide the control device with the appropriate operating parameters for the various operating phases, a memory device is also provided in which operating parameters that can be called up by the control device can be stored. The electronic ballast according to the invention is characterized by a digital data interface that provides a connection to an external communication device, with at least part of the specified memory device being designed as a writable, non-volatile memory. A means is also provided for writing the operating parameters to be transmitted via the data interface into the non-volatile memory. The inventive design of the electronic ballast

The electronic ballast therefore makes it possible for user-specific operating parameters, for example for operating special lamp types or even custom lamp designs, to be written into the operating data memory of the electronic ballast before the lamp is actually operated. Accordingly, the electronic ballast according to the invention is designed in such a way that it can be programmed before it is operated. This means that the ballast according to the invention can be specifically set to the connected or to be connected lamp type before operation with the respective lamp, so that each lamp can be operated with its own, optimized operating parameters, as long as these operating parameters can be implemented by the electronic ballast. This allows a previously unattainable level of flexibility to meet the respective needs of the user, so that, for example, a very large number of lamp types can be set with a single ballast according to the invention. Compared to ballasts that have previously stored the operating data of a number of lamp types, the ballast according to the invention also has the advantage that the memory device for storing the operating data of all lamps does not have to be large, since the user can write the relevant operating parameters into the writable memory, adapted to the respective needs. In many cases it is also possible to store the operating data of just one lamp type, namely the exact lamp type that is to be operated with the ballast according to the invention. In this respect, the otherwise usual lamp detection circuit can also be omitted in many cases without losing the flexibility described.

The invention is based on the idea of providing an electronic ballast with a high degree of adaptability to the respective requirements by giving the user the possibility of storing the operating data required for the operation of the respective lamp in the digital operating data memory of the

EVGs. Such a memory can include, for example, a PROM, an EPROM, or an EEPROM or even a flash memory. While the EEPROM requires a write voltage of 20 V and can be erased and written line by line, a flash memory can be erased or written block by block, whereby the entire control electronics, including the write voltage of 12 V or 5 V, are already provided by the memory chip itself. In principle, all digital interfaces are possible as possible data interfaces with which

&iacgr;&ogr; Data can be transmitted to the electronic ballast, for example a serial, parallel or even an air interface such as an infrared interface or a Bluetooth interface. While a PROM only needs to be written once by the user with the necessary operating data of the lamp, the erasable memories have the additional advantage that a ballast according to the invention equipped with them can be easily adapted to new requirements even when installed, by replacing old operating data with new ones without having to replace hardware.

In order to keep the hardware effort to a minimum, it can be provided that the control device of the ballast, which controls the inverter, for example, is also connected to the data interface via a data path and can therefore further process the received data and/or store it in the writable, non-volatile memory. In this way, another control device for controlling the writing process is saved.

0 The electronic ballast according to the invention can advantageously also have a lamp detection circuit as disclosed, for example, in the above-mentioned European patent. This allows information associated with the detected lamp type to be transmitted via the data interface to the external communication device, in which subsequent information processing takes place.

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In principle, any operating parameters required by the control device for operating the respective lamp connected to the electronic ballast according to the invention can be stored in the writable, non-volatile memory. These operating parameters can of course also include various phases of operation, such as preheating operation, ignition operation and/or lamp operation.

It is particularly advantageous if information relating to the ballast, for example identifying it or specifying operating limits, is stored in a memory of the electronic ballast, with this information being transferable via the data interface. In this way, electronically processable information can be passed on via the ballast and in particular can be received and further processed by a connected external communication device.

0 The object of the invention is further achieved by an external communication device which can be connected via the specified interface to the electronic ballast according to the invention for the time of programming the non-volatile memory in the electronic ballast and before the actual operation of the lamp. For this purpose, the external communication device has a digital data interface designed corresponding to the data interface of the ballast for connection to the electronic ballast. Furthermore, a processor device for controlling the device and an input device for determining operating parameters to be sent to the ballast via the data interface and stored in the writable, non-volatile memory of the ballast are included.

5 The external communication device according to the invention makes it possible to use the information required by the electronic ballast.

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The communication device is also used to program the ECG and adapt it to the respective lamp by transferring the lamp-specific operating parameters and writing them into the non-volatile memory before the ECG is actually operated with a lamp. The ECG and the external communication device are then separated again.

It can be provided that the operating parameters in the device can be selected directly using the input device or indirectly by selecting a lamp type, whereby the operating parameters associated with the selected lamp type can be identified and transmitted to the electronic ballast via the data interface. To facilitate the determination of the operating parameters to be transmitted to the ballast, the external communication device can comprise program means via which this determination process is controlled, in particular in response to inputs using the input device. In particular, the program means can guide the user via menus to select the optimal operating parameters for the respective lamp.

It may be expedient for the external communication device to comprise a memory device in which operating parameters for different lamp types are stored. If, for example, a specific lamp type is selected, the associated operating parameters can be read out from the memory device and transmitted by the communication device to the electronic ballast and stored there in the non-volatile memory.

Advantageously, the external communication device can comprise a means, in particular a program means, for automatically selecting at least one lamp type from a predetermined number 5 of lamp types and a means for determining the data associated with the selected lamp type, which can be transmitted via the data interface to the

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operating parameters to be transmitted to the ballast.

The external communication device can expediently also comprise a means for checking, in response to information transmitted from the ballast via the data interface relating to the ballast and/or to a lamp connected to the ballast, whether selected operating parameters are compatible with the information received from the ballast. This can ensure that the user cannot write operating data into the ballast which cannot be carried out with the electronic ballast.

In order to enable the user of the external communication device according to the invention to operate it easily, a means, in particular a program means, can be provided for selecting lamp types and/or operating parameters in response to information transmitted via the data interface relating to the ballast and/or relating to a lamp connected to the ballast. In this way, work can be taken off the user's hands insofar as only the operating parameters or lamp types that are useful in the respective situation are automatically displayed on a display device, from which the user can then select the one he wants.

The invention is described below with reference to the accompanying figure, which shows an embodiment of an electronic ballast 0 designed according to the invention, which is connected to an external communication device according to the invention.

In Fig. 1 is shown an electronic ballast 100 designed according to the invention, which is connected to an external communication device 200. In this embodiment, the ballast has a mains connection 110, to which a

Rectifier 111 is connected downstream. The direct current is fed to a storage capacitor 113 via a sine wave regulator 112. The direct voltage is chopped in this case by a half bridge, the switches of which are designed as MOSFET transistors 114, 115. A choke coil 116 is arranged at the output of the inverter, with which the lamp 117 is connected in series. The halving capacitors 119, 120 complete the inverter for operating the lamp. An ignition capacitor 118 is connected to the coils 117a, 117b of the lamp 117. A detection device 124 for detecting the current and/or the voltage of the lamp 117 supplies digitized data associated with the detected values to the control device, which comprises a processor 121 as a central component. This 121 controls a clock generator 125, which drives the switching transistors 114, 115 of the half-bridge. The processor has access to a memory device 122, which has a ROM 122a and a writable and erasable flash memory 122b as non-volatile components. It also includes a serial interface 123, via which data can be exchanged with external devices. The processor 121 serves as a processing device, which receives the data supplied from outside and stores it, for example, in the flash memory 122b. This flash memory is connected to a control line (not shown in detail), with which the processor can inform the memory 122b that new data is to be written. As is known to those skilled in the art, the flash memory has the necessary means for writing the data transmitted to it by the processor 121, and these means can be activated by the processor using the control line mentioned. In this case, the flash memory records the data and performs the usual flash control, in which the corresponding cells in the memory cell array are controlled with a short voltage pulse of 5 V with a typical duration of 100 μ3. This writing process, like the erasing process, is well known in the field, which is why it does not need to be discussed further below.

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The following briefly describes the mode of operation of the electronic ballast shown in Fig. 1 with regard to lamp control. It is assumed that the corresponding operating parameters for the lamp used are stored in the ROM 122a or in the flash memory 122b. When the electronic ballast is started, a preheating period begins, during which the coils 117 a, 117 b are heated with a predetermined current over a predetermined time.

The lamp 117 is preheated by a current flowing through the coils. In this case, the processor 121 reads the flash memory 122b for the preheating phase, in which a preheating time of 1 s at a current of 1 A is stored for the lamp type used. The processor now controls the clock generator 125 so that the two predetermined values are maintained. The clock frequency is selected to be high enough that the heating current can flow through the ignition transistor 118. The current is measured by the detection device 124 and regulated by the processor to the target current, here 1 A. After one second, the preheating time is over and the ignition phase can begin.

The parameters relevant for the ignition phase are the output voltage with which the ignition attempts are started, an upper threshold value at which the ignition phase is interrupted if the lamp has not ignited before this threshold value is reached, and the voltage steps by which the applied ignition voltage is increased. These parameters are again read out from the flash memory 122b and then the transistors 114, 115 are controlled. Starting from the base voltage, here 300 V, the ignition voltage is applied for a period of 100 ms and the detection device 124 checks whether a lamp current is flowing, i.e. whether the lamp has ignited. If this is not the case after the specified period, the voltage is increased by a step of 70 V and applied to the lamp again for the specified period of 100 ms. If the

Control device even after reaching the threshold voltage, here 800 V, if the lamp has not yet ignited, an error message is triggered by controlling an LED.

However, if the lamp is ignited, it is controlled for lamp operation, in this case for a power of 40 W at an operating current of 300 mA. These parameters were also read from the flash memory 122b by the processor 121 before they were set and regulated.

The described mode of operation regarding the control of the lamp 117 is identical to that of a conventional electronic ballast in which the operating data are stored in an operating data memory.

As already explained, the electronic ballast according to the invention shown in Fig. 1 has a serial interface 123 via which data can be exchanged with an external communication device 200, see Fig. 1.

This communication device 200 has a display device 214 in the form of a screen and an input device 212 in the form of a keyboard. A central processor 211 has access to a memory 213. The data received via the data interface 210 are processed by the processor 211 or the processor can send selected data to the ballast via the serial interface 210. In the present case, the two serial data interfaces are designed as USB interfaces, so the bus controllers (not shown) recognize the connection of the other device. A unique identifier relating to the ballast is stored in the ROM 122a of the electronic ballast, which is read out by the processor 121 and transmitted to the communication device 200 via the serial interfaces 123, 210. Its processor 211 records the identifier and recognizes which electronic ballast is connected. A database is stored in the memory 213 with

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possible lamp types and their associated operating parameters. In the same memory 213, an assignment of various electronic ballasts and their possible operating data is stored in a second database, so that this information records which operating parameters the connected electronic ballast can support. In response to this information, the processor 211 selects from the lamp type to operating parameter database those which are supported by the connected electronic ballast (EB). These are then displayed on the screen 214. The user can now select the corresponding lamp type via the keyboard 212 and start the transmission of the associated operating parameters to the ECG. The transmitted data is recorded by the processor 121, transmitted to the flash memory 122b and at the same time the write control of the flash memory is triggered. The transmitted data is then written to the flash memory 122b in the conventional manner and is available for the subsequent operation of the ECG with the selected lamp.

After programming the ECG 100, the connection to the external communication device 200 is released again and the ECG can be operated with the connected lamp using the programmed operating parameters.

In another program-supported mode, the user can select the individual operating parameters directly on the external communication device and then transmit them to the ECG and write them into the flash memory.

In an automatic mode, the property of the electronic ballast shown in Fig. 1 is used to detect the lamp type connected to the electronic ballast in accordance with the European patent specified above. This information is sent by the control device 121 via the interfaces 123 and 210 to the communication device.

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device and recorded by its processor. The latter reads the operating parameters assigned to the lamp type from its memory and transmits them to the electronic ballast, in which the data are written into the flash memory 122b as described.

LlPPERT, STACHOW, SCHMIDT & PARTNER Ju/ha

Patent Attorneys European Patent Attorneys European Trademark Attorneys

P.O. Box 30 02 08, D-51412 Bergisch Gladbach 5 August 2003

Telephone +49 (0) 22 04.92 33-0
Fax +49 (0) 22 04.6 26 06

Electronic ballast with writable parameter memory and associated communication device

List of reference symbols

100 Ballast

110 power connections

111 Rectifier 112 Sine wave regulator

113 Storage capacitor

114 Transistor

115 Transistor

116 Throttle
0 117 Lamp

117a,

117b spiral

118 Ignition capacitor

119 Halving capacitor 120 Halving capacitor

121 Processor

122 Storage device 122a ROM

122b Flash memory 123 serial interface

124 Recording device

125 Clock generator

200 Communication device 210 Serial interface 211 Processor

212 Input device

213 Storage

214 Display device

Claims (9)

1. Electronic ballast for operating a gas discharge lamp comprising: - a connection device for applying a supply voltage to the ballast; - an inverter connected to the input side of the connection device for generating a high-frequency alternating voltage to supply the gas discharge lamp, which is - is controlled by a control device; - a choke connected to the output of the inverter, whereby the lamp can be connected in series to the choke, and - a storage device in which operating parameters that can be called up by the control device can be stored, characterized by a digital data interface ( 123 ) which provides a connection to an external communication device ( 200 ), wherein at least part of the memory device is designed as a writable, non-volatile memory ( 122 b), and a means for writing the operating parameters to be transmitted via the data interface into the non-volatile memory, so that the ballast can be programmed before operation. 2. Electronic ballast according to claim 1, characterized in that the data interface ( 123 ) is connected to the control device ( 121 ) for controlling the inverter. 3. Electronic ballast according to claim 1 or 2, characterized in that the control device ( 121 ) is designed to detect the lamp type connected to the ballast, wherein information associated with the detected lamp type can be transmitted to the external communication device via the data interface. 4. Electronic ballast according to claim 1, 2 or 3, characterized in that operating parameters relating to the preheating operation, the ignition operation and/or the lamp operation are stored in the writable, non-volatile memory ( 122 b). 5. Electronic ballast according to claim 1, 2, 3 or 4, characterized in that information concerning the ballast is stored in a memory ( 122a ), which information can be transmitted via the data interface ( 123 ). 6. External communication device ( 200 ) for an electronic ballast ( 100 ) according to one of claims 1 to 5 for programming the same before its operation with - a digital data interface ( 210 ) for connection to an electronic ballast ( 100 ), - a processor device ( 211 ) for controlling the device, - Means, in particular an input device ( 212 ), for determining operating parameters to be sent to the ballast via the data interface ( 210 ) and stored in the writable, non-volatile memory. 7. External communication device according to claim 6, characterized by a means for selecting at least one lamp type from a predetermined number of lamp types and a means for determining the operating parameters associated with the selected lamp type to be transmitted to the ballast via the data interface. 8. External communication device according to claim 6 or 7, characterized by a means for checking, in response to information transmitted from the ballast via the data interface concerning the ballast and/or concerning a lamp connected to the ballast, whether selected operating parameters are compatible with the transmitted information. 9. External communication device according to claim 6, 7 or 8, characterized by a means for selecting lamp types and/or operating parameters in response to information transmitted via the data interface concerning the ballast and/or concerning a lamp connected to the ballast and a means for displaying the selected lamp types and/or operating parameters on a display device.