Abstract: A light-transmissive discharge vessel (1) encloses a discharge space (10) which contains an ionizable filling comprising an evaporable component. The low-pressure discharge lamp is also provided with coil for maintaining an electric discharge in the discharge space, and with a carrier (3) with a resilient body (30) and an open holder (31). The resilient body (30) is clamped inside a tube (14) which communicates with the discharge space (10). The holder (31) is clamped inside the resilient body (30). In the absence of the holder (31), the resilient body (30) can be inserted in a released state in the tube (14) with play (x).

Abstract: An illumination unit including an electrodeless low-pressure discharge lamp (20) and a supply device (50). The lamp has a discharge vessel (30) which encloses in a gastight manner a discharge space (31) which is provided with an ionizable filling. The lamp (20) further has a coil (40) provided with a winding (42) around a sintered core (41) of polycrystalline ferrite material, which winding (42) is connected to the supply device (50). The coil (40) is capable of inducing a high-frequency magnetic field which maintains a discharge in the discharge space (31). The losses in the core (41), when measured at room temperature in a magnetic field with a frequency of 3 MHz and a magnetic flux density of 10 mT, amount to at most 150 mW/cm.sup.3. This has the advantage that the lamp (20) ignites comparatively quickly and loads the supply device (50) comparatively weakly during ignition. The supply device (50) as a result can have a comparatively long useful life.

Abstract: An electric lamp according to the invention comprises a lamp vessel (10) which is closed in a gastight manner, which has an end portion (11), and which surrounds a light source (12). The lamp vessel supports a cylindrical collar (30) with an axis (31) at its end portion (11). One or several projections (33a, 33b, 33c) of a first coupling member (30) which each grip into a respective recess (41a, 41c) of a second coupling member (40) couple the collar (30) to a mounting member (40) for fastening the lamp to a carrier. At least one of the coupling members (30) is made of an elastic material.

Abstract: An electrodeless low-pressure discharge lamp according to the invention has a lamp vessel (1) which is closed in a gastight manner, which contains an ionizable filling, and which has a cavity (10). In the cavity (10) an elongate coil (2) is positioned with a primary and a secondary winding (21, 22, respectively) of an electrical conductor (20) around a coil former (3) which has a tip (30) which points into the cavity (10). The electrical conductor (20) from which the secondary winding (22) is formed extends from a first end (22a) of the secondary winding (22) facing the tip (30) into a recess (32) of the tip (30) of the coil former (3) and is clamped therein. The first end (22a) of the secondary winding (22) can be easily fastened in this manner.

Abstract: An electrodeless low-pressure discharge lamp according to the invention is provided with a lamp vessel which is closed in a gastight manner and which has an ionizable filling. The lamp vessel has an end portion with a cavity in which an electric coil is accommodated. The cavity further contains a heat conductor which extends to outside the cavity and has a flange there with an axis, a circumference, a surface which faces away from the lamp vessel and a surface which faces the lamp vessel. A mounting member is connected to the lamp vessel and fastened against the flange. The mounting member is provided with at least one hook which points radially inwards and which cooperates with a recess in the surface of the flange which faces away from the lamp vessel. The recess issues into an axial groove at the circumference of the flange extending into the surface facing the lamp vessel. This construction renders possible a quick assembly of the mounting member with the flange.

Abstract: A discharge vessel (10) closed in a gastight manner has a cavity (11) enclosing a discharge space provided with an ionizable filling. A coil (20) with a winding (21) of an electric conductor and an assembly (30) of a heat conductor (31) and one or several elongate cores (32) of soft-magnetic material are accommodated in the cavity. The cores (32) are arranged along a longitudinal axis (33) of the heat conductor (31) in one or several recesses (34) of the heat conductor which issue into a circumferential surface (36) of the assembly (30). The heat conductor (31) occupies at least half the circumference in a cross-section perpendicular to the longitudinal axis (33) of the assembly (30). The construction of the lamp according to the invention renders possible lamp operation at higher lamp powers also without the use of a heat pipe.

Abstract: A lighting unit according to the invention comprises an electrodeless low-pressure discharge lamp and a high-frequency supply. The electrodeless low-pressure discharge lamp is provided with a discharge vessel which is closed in a gastight manner, comprises an ionizable filling, and has an enveloping portion and a recessed portion surrounded by the enveloping portion, which enveloping and recessed portions of the discharge vessel each support a luminescent layer. The electrodeless low-pressure discharge lamp is in addition provided with a coil which is arranged in the recessed portion of the discharge vessel and which is electrically connected to the supply. The conversion efficiency of the luminescent layer on the recessed portion is relatively high compared with that of the luminescent layer on the enveloping portion. This measure renders possible a lower temperature of the core.

Abstract: An electrodeless low-pressure discharge lamp (10) according to the invention is provided with a radiation-transmitting discharge vessel (11) which encloses a discharge space (14) containing an ionizable filling in a gastight manner. The lamp (10) is in addition provided with a first and a second winding (20, 23) for conducting a high-frequency current during operation. The first winding (20) extends along a longitudinal axis (29) in a cavity (28) surrounded by the discharge vessel (11). The second winding (23) is arranged along the longitudinal axis (29) in the extended direction of the first winding (20) outside the cavity (18) surrounded by the discharge vessel (11). During operation, the currents in the first and second windings (20, 23) have the same tangential direction relative to the longitudinal axis (29). The lamp causes comparatively little magnetic interference, while it is avoided that the second winding (23) hampers lamp ignition or causes an unstable lamp operation.

Abstract: An illumination unit comprises an electrodeless low-pressure discharge-lamp and a high-frequency power supply unit. The lamp has a gastight closed discharge vessel with an ionizable fill and a coil with turns of a primary and a secondary winding around a core of soft-magnetic material. The power supply unit has input terminals, a first output terminal, electrically neutral with respect to ground, that is connected to a first end of the primary winding, and a further output terminal that is connected to a second end of the primary winding. During nominal lamp operation the primary winding excites a high-frequency magnetic field that maintains an electrical discharge in the discharge vessel and that induces in the secondary winding a potential drop in the direction of a first, with respect to the electrically neutral end, to a second free end that varies in a sense opposite to the potential drop from the first to the second end in the first winding.

Abstract: The electrodeless low pressure discharge lamp has a lamp vessel (1) which is fused to the flared portion (6) of a flared tube (5) which extends into the lamp vessel. A power coupler (20) is demountably secured to the lamp vessel and comprises a soft magnetic core (21), surrounded by an electric coil (22), and a heat conducting element (23) in the core. This element is a solid rod, the coil (22) is present in a region (8) adjacent the flared portion (6) of the flared tube (5), and an elastic material couples the rod (23) laterally to the core (21). The construction of the lamp avoids the use of an expensive heat pipe as a heat conducting element.

Abstract: An electrodeless low-pressure discharge lamp includes a translucent discharge-vessel of a glass that contains at least 5 weight % sodium, encloses a discharge-space and includes a mercury containing fill. The lamp further includes a device to maintain an electrical discharge in the discharge space and an auxiliary radiation source that emits at least 0.5 mW of visible radiation when activated, to provide a relatively short ignition time.

Abstract: An illumination unit of the invention comprises an electrodeless low-pressure discharge-lamp (10) and a high-frequency power supply (50). The lamp (10) is provided with a gastight closed discharge vessel (20) with an ionizable fill (21). The lamp (10) further is provided with a coil (30) with turns (31,32) of a primary and a secondary winding (33,34). The power supply unit 50 is provided with input terminals (51a,51b) and is further provided with a first output terminal (52a), electrically neutral with respect to mass, that is connected to a first end (36a) of the primary winding (33) and with a further output terminal (52b) that is connected to a second end (36b) of the primary winding (33).

Abstract: A high-pressure sodium vapor discharge lamp having a ceramic discharge vessel, which has over a length L a substantially constant inner diameter and in which electrodes are arranged opposite to each other at a relative distance D. The lamp emits white light during operation and consumes a power of at most 50 watts. The lamp has a high efficiency and good color rendering due to the fact that D/L.ltoreq.0.5.