Tridonic Gmbh Co. Kg

Stefan Stark

Deepak Makwana

Harald Netzer

Lukas Saccavini

Ludwig Erasmus De Clercq

Hans Auer

Jagjitpati Shukla

Clemens Kucera

Fabio Romano

Andreas Schmölzer

Sascha Gstir

Lukas Hauer

Benjamin Lanza

The invention relates to a method () for operating an isolated primary side switched converter () for providing a voltage supply to an LED load (), wherein the converter comprises a galvanic isolation stage (), the method comprising the steps of:

Primary side switched converter for providing a voltage supply to an LED load

The invention relates to an isolated resonant primary side switched converter (), comprising a galvanic isolation stage (), an auxiliary winding (L-) on the primary side () of the isolation stage () which is magnetically coupled to at least one secondary side winding (L-, L-) of the isolation stage (), wherein the auxiliary winding (L-) is configured to detect a feedback signal as to a secondary side voltage, and a control unit () configured to sample the feedback signal, in each or every nswitching cycle, during a sampling period in which a current is flowing on the secondary side () of the isolation stage (), and to process the sampled signal for a feedback control of the secondary side voltage by controlling the switching operation of a primary side switch (M, M).

Isolated primary side switched converter

The invention relates to an isolated converter () for providing a current supply to an LED load, comprising: a galvanic isolation stage (); a sensing circuit () on a primary side of the isolation stage (), which is magnetically coupled to a secondary side of the isolation stage (); wherein the sensing circuit () is configured to receive a feedback signal that is proportional to a secondary side current; and a control unit () configured to determine an output current of the converter () based on the feedback signal; wherein at least one electrical characteristic of the sensing circuit () and/or the control unit () is adjustable to convert the feedback signal from a first ratio to a second ratio to the secondary side current.

Isolated converter with improved current sensing

The invention relates to an LLC stage for an LED driver (), comprising a half bridge or full-bridge circuit () comprising two switches (M, M), connected in series, a control circuitry (), such as e.g. a microcontroller or ASIC, for controlling switching operations of the switches (M, M), wherein the control circuitry () for switches is arranged to monitor the middle point voltage between the two switches (M, M) and enables the switch on of one of the switches (M, M) only if the middle point voltage meets defined criteria. The control circuitry () is designed to issue an error signal, if a dead time, during which both switches are non-conducting and resulting from the monitoring of the midpoint voltage, is greater than a preset threshold value.

LLC stage for LED drivers

The invention relates to a synchronous flyback converter () having terminals for supplying an LED load. The synchronous flyback converter () comprises a sensing winding (L) coupled to a primary winding (L) of a transformer T of the flyback converter (), a control unit () controlling a primary side switch (S) in series to the primary winding (L) of the flyback converter () using a feedback signal for a closed loop control of a secondary side voltage of the flyback converter () by controlling the frequency and/or duty cycle of the switching of the primary side switch (S), wherein the feedback signal is derived from a sensing voltage across the sensing winding (L) sampled once during a switch-on time of a secondary side switch (S) of the flyback converter ().

Synchronous flyback converter for driving LED loads

The invention relates to an LED-driver, comprising an actively switched PFC circuitry and a bus interface for a wire-bound bus, wherein a voltage supply for the bus interface for powering the bus is tapped off the output voltage of the active PFC circuitry, further comprising a control circuitry for a feedback control of an output voltage of the actively switched PFC by controlling a switch of the PFC, wherein the time constant of the feedback control of the control circuitry is faster during time periods in which the bus interface is transmitting or receiving signals, compared to time periods without activity.

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Muntlix, Austria

Stefan Stark