Abstract: The invention relates to an apparatus for operating at least one light-emitting diode (LD) comprising an electronic transformer (10), the output of the electronic transformer (10) having a high-frequency rectifier (12) connected to it whose output is connected to at least one light-emitting diode (LD), the high-frequency rectifier (12) and the at least one light-emitting diode (LD) being combined to form a separate physical unit (14).

Abstract: To provide enhanced starting voltages for fluorescent lamps operating, for xample, from 110 V power networks through a rectifier, and in which a high-frequency oscillatory circuit is used which includes a ring core transformer (TR1, TR2, TR3) operated under saturation conditions, and controlling switching transistors (T1, T2), which have emitter-resistors (R4, R5) connected thereto to stabilize the operation of the circuit and of the transistors, at least one diode (FIG. 4: D4, D5) is connected in parallel to at least one of the emitter resistors; for some circuits (FIGS. 2-4) a diode, or two diodes (D6, D7, D8, D9) can form the emitter-resistors or resistors.

Abstract: At least two discharge units (2, 3; 14, 15, 16; 21, 22, 23, 27, 28, 29) are ocated adjacent each other, each of the discharge units preferably including a unitary U-shaped tube having two longitudinal leg portions (2a, 2b; 3a, 3b) extending parallel to each other, and a cross portion (4, 5) connecting the leg portions at the base of the U. The free ends of the U are pinch-sealed and air-tight, and the two discharge units are so positioned relative to each other that the longitudinal leg portions extend parallel to each other, selectively, in a single plane, in parallel planes, or angled with respect to each other; the cross elements are located at adjacent end portions of the respective units.