U.S. Philips Corporation

Adrianus M De Bijl

Johannes M Van Meurs

Hubertus M Chermin

Pieter J Bolhuis

Hans Cramwinckel

Jozef C Moerkens

Lambertus J Bouwman

Henri A Melai

Bernardus J Overgoor

Johannes H Op Het Veld

Johannes A De Vogel

A lampholder in accordance with the invention can suitably be used for a low-pressure discharge lamp (a) which operates at a high frequency and which comprises an elongated, tubular discharge vessel (b), said lamp being provided with a pair of electrodes (c, c') for maintaining an electric discharge in the discharge vessel. The lampholder (0) has contacts (1, 1') for connecting a high-frequency power supply (4), said contacts being electrically connected to a first (2) and a second terminal (2') for connecting the lamp. The second terminal is further removed from the contacts than the first terminal. A compensation conductor (6) extending between the first (2) and the second terminal (2') is connected to said first terminal (2). This leads to a reduction of conducted interference.

Lampholder and lighting unit comprising a lampholder

The invention relates to a circuit arrangement for operating a discharge lamp, comprising a DC-AC converter provided with switching elements and a drive circuit for rendering the switching elements alternately conducting. The circuit arrangement is furthermore provided with a control circuit C for controlling the power consumed by the lamp. To this end, the control circuit is coupled to a current sensor. According to the invention, the current sensor is so positioned that the power consumed by the lamp can be controlled independently of the build-up of the drive circuit and that a simple construction of the control circuit C is possible.

Discharge lamp control circuit arrangement

A DC/AC converter for igniting and supplying a gas discharge lamp (1). The converter has two input terminals (C, D) intended to be connected to a DC voltage source, said input terminals (C, D) being connected together by means of a series arrangement including a load circuit comprising at least an induction coil (10) and a parallel arrangement of the lamp and a capacitor (12), as well as a first semiconductor switching element (13). The load circuit is shunted by a circuit comprising a second semiconductor switching element (14). The semiconductor switching elements (13, 14) are rendered alternately conductive and non-conductive by means of control circuits (13a, 14a). A second capacitor (11) is arranged in series with the induction coil (10) and the lamp. The second capacitor is shunted by a third switching element (15) which is non-conductive during the pre-heat period of the lamp electrodes (2, 3) and is conductive at least during ignition of the lamp.

DC/AC converter for igniting and supplying a gas discharge lamp

An electric arrangement for igniting and supplying a gas discharge lamp (1). The arrangement is connected to an alternating voltage source and comprises a rectifier bridge (7) connected to a DC/DC converter provided with a rectifier element (11), a coil (10) and a high-frequency switched semiconductor switching element (12) coupled to a drive circuit. The DC/DC converter is connected to the input terminals (16, 17) of a high-frequency DC/AC converter incorporating the lamp and provided with semiconductor switching elements (21,24). A capacitor (15) is arranged between the input terminals of the DC/AC converter and a sensor (22) for measuring the converter current is arranged between one of the input terminals (17) and a semiconductor switching element (21) of the DC/AC converter. The lamp is connected in series with a frequency-dependent impedance 20. A drive circuit (13) of the semiconductor switching element in the DC/DC converter is coupled to a control circuit (14) and is also coupled to the capacitor (15). The voltage across the capacitor (15) is set to a desired value by adjusting the frequency and the period of conductance of the semiconductor switching element (12). The sensor (22) is coupled to a second control circuit (27) which is connected to the drive circuits (21a, 24a) of the semiconductor switching elements (21, 24) of the DC/AC converter whereby the frequency and/or period of conductance of the switching elements of the DC/AC converter, and hence the power consumption of the lamp, can be regulated.

Circuit for supplying constant power to a gas discharge lamp

A DC/AC converter for igniting and supplying a gas discharge lamp (1) has two input terminals (C, D) intended to be connected to a DC voltage source. These input terminals are connected together by means of a series arrangement of a load circuit comprising at least the discharge lamp (1) and an induction coil (8), as well as a first semiconductor switching element (9). This load circuit being shunted by a circuit comprising a second semiconductor switching element (10). The switching elements (9, 10) are rendered alternately conductive and non conductive at a high frequency. The lamp is shunted by a third semiconductor switching element (12) which is conductive while the lamp electrodes (2, 3) are being pre-heated, whereafter the converter is rendered inoperative for a short period of time in order to ignite the lamp, which time is shorter than the time required to cool the lamp electrodes to below their emission temperature. The converter is thereafter rendered operative again.

A DC/AC converter provided with two transistors (11 and 20) alternately conductive to supply current to an inductively stabilized discharge lamp (16, 15) to be connected to the converter. The lamp is connected in series with a primary winding (12) of a current transformer. A secondary winding (30, 31) of the transformer is connected to a timing circuit (32 to 35; 32' to 35') of a control device of the transistors. The timing circuit is provided with voltage-dependent elements, i.e. Zener diodes (35, 35'). The combination of the current transformer and the Zener diodes causes the frequency of the converter, during starting of the lamp, to be larger than during the operating condition of the lamp. This insures that the lamp electrodes are properly heated before the lamp ignites.

DC/AC Converter with voltage dependent timing circuit for discharge lamps

An electronic device (20-61) for the starting and a.c. operation of a capacitively stabilized discharge lamp (7) includes a controlled semiconductor switching element (22) which, in the operating condition of the lamp, is briefly conductive in each half cycle of the AC supply. The control circuit of the semiconductor switching element (22) includes a second switching element (25) which, during the starting procedure of the lamp, ensures that the semiconductor switching element (22) is made conductive only every alternate half cycle thereby to improve the ignition of the lamp.

Electronic device for the starting and a.c. voltage operation of a gas

The invention relates to an arrangement comprising a gas and/or vapor discharge lamp (5) which includes a discharge tube (5a). An electronic auxiliary device (10-16) is arranged in parallel with the discharge lamp (5). This auxiliary device ensures that in the operating condition the lamp is shunted briefly during each half cycle of the power supply. With an arrangement according to the invention, the lamp (5) is of a type in which the discharge tube (5a) has a temperature of at least 200.degree. C. in the operating condition. The auxiliary device is connected to sensor elements (20; 25-28) which ensure that the lamp (5) is not shunted in the period of time in which the lamp (5) has not yet reached the operating condition. This achieves reliable starting of the lamp.

Arrangement including a gas and/or vapor discharge lamp

The invention relates to an electric arrangement comprising two series-arranged discharge tubes which are provided with preheatable electrodes and which are stabilized by means of a relatively small ballast. The tubes are shunted by a semi-conductor switching element which operates in the operating condition of the tubes. According to the invention a control circuit of the semi-conductor switching element includes a non-linear circuit element which ensures that the discharge tubes do not ignite before the electrodes are in the warm state.

Electric arrangement including at least one gas and/or vapor discharge

A Computer system which includes a central processing unit, a central memory storage unit and a plurality of peripheral devices, the central processing unit having a control unit for dividing single complete input/output instructions for the transfer of data within the system into a sequence of discrete, separately executable, time independent operation instructions under the control of a microprogram. The system further includes peripheral device control units for the control of the independent execution of the discrete divided input/output (I/O) operation instructions. A microprogram command line is connected to the control unit in the central processing unit for controlling the output of the discrete I/O operation instructions along the system bus. An interruption request unit is also included within each of the peripheral device control units for generating an interrupt in the central processing unit after the termination of an operation instruction, both to permit the updated status of instructions to be recorded and to indicate the availability of a specific I/O device for further use. After the control unit in the central processing unit divides single complete input/output instructions into a plurality of separate operation instructions for operation steps which relate to particular functional characteristics of the peripheral devices in the system, the peripheral device control units control the individual execution of each separate operation in a specific sequence but independently of each other in time within that sequence. The individual data operations are transferred over the bus of the system.

Bus-organized computer system with independent execution control

An address conversion device for use with computer systems including a central processing unit and peripheral memory storage devices, such as discs, tapes and bubble memories, which serve for secondary data storage and in which binary data elements are stored in sequential addressable storage sectors. Such storage sectors have precise physical locations on the peripheral storage units. The address conversion device includes a first conversion unit which controls the conversion of user program addresses to logical addresses reflecting the logical structure of the data files stored in the peripheral storage units and a second conversion unit which converts the logical addresses to precise physical addresses of sectors of the secondary storage units in the form of electrical signals, such that the secondary storage units can be addressed as if they were random access units. Replacement of one type of secondary storage unit by another requires only a programmed change of quantitative parameters in the program controlling the address conversion device.

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Eindhoven, Netherlands

Adrianus M De Bijl