Tridonic Gmbh Co. Kg

Tridonic UK Ltd.

Jamie Kelly

Deepak Makwana

Günter Marent

Paul Dalby

Wayne Bell

Shukla Jagjitpati

Kevin McDermott

Chong Ng

Günther Marent

The invention is related to a driving circuit that provides an operating current for at least one lighting means. The driving circuit comprises an isolated switched converter having a switch () controlled by a control circuit (), wherein a primary side choke () is charged when the switch () is in its conducting state and the primary side choke () is discharged when the control circuit () controls the switch () in its non-conducting state. The circuit comprises first determining means () for monitoring the current through the primary side choke (), and second determining means () for determining a switch-off time, wherein the second determining means () comprises an auxiliary winding () coupled to a secondary side choke () and the second determining means () is configured to monitor the voltage across the auxiliary winding () for determining a switch-off time.

Driving circuit and method for a provision of an operating current for at least one lighting means

A driver circuit () for a light source () comprises an input configured for coupling to a power line (). A control device () is configured to control at least one controllable switch () to control an output current or output voltage of the driver circuit (). The control device () is configured to modulate a signal onto the power line () by setting a switching frequency of the at least one controllable switch () in dependence on data to be transmitted by the driver circuit () over the power line ().

Driver circuit for a light source and method of transmitting data over a power line

The invention relates to an operating device () for lighting means (), having a circuit () for dividing a rectified alternating voltage to direct voltages of lower levels, wherein the circuit () comprises a PFC block comprising a plurality of half bridge converters () that are arranged such that the sum of the input voltage drops across the half bridge converters () corresponds to the value of the rectified alternating voltage, wherein the circuit () is the first active stage in a power supply for the lighting means ().

PFC with stacked half-bridges on DC side of rectifier

A converter for supplying current to a light emitting means (), the converter () comprising: an input () configured to receive a direct current supply voltage;at least a first controllable switch () electrically connected between the input () and an inductor (), and a second controllable switch () electrically connected between the input () and the inductor (); a first diode () and a second diode () connected in series; a first capacitance () connected in parallel with the first diode () and a second capacitance () connected in parallel with the second diode (); the inductor () having a terminal coupled to the at least one controllable switch (-) and another terminal coupled to an anode of the first diode () and a cathode of the second diode (); and a control device () to control the first controllable switch () and the second controllable switch (), wherein the control device () is configured to adjust a switching frequency of the first controllable switch () and of the second controllable switch () to set an output current of the converter ().

Converter and method of operating a converter for supplying current to a light emitting means

A power factor correction circuit includes an inductor L1, a diode D1, a switch Q3 and a controller. An input voltage Vis applied to the inductor L1 which is cyclically discharged through the diode D1 by the operation of the switch Q3. The switch Q3 is controlled by the controllerwhich varies the on period of the switch Q3, during which the inductor is charged, for adjusting an output voltage Vtowards a target value V. The method includes obtaining an indication of the inductor L1 reaching a discharged state in response to the switch being in an off state. The controllermonitors at least one of the switch on period Tand the switch off period Tto identify when the input voltage Vis an alternating voltage AC input, and when it is likely to be a non-alternating voltage DC input. When a non alternating voltage is detected, steps may be taken to reduce interference.

Power factor correction

A power factor correction circuit includes an inductor L, a diode D, a switch Qand a controller. An input voltage Vis applied to the inductor Lwhich is cyclically discharged through the diode Dby the operation of the switch Q. The method of operation includes: operating a controllerto obtain an indication of the voltage across the switch Q, monitoring the indication of the voltage across the switch Qto determine when the inductor Lreaches a discharged state in response to the switch being in an off state, and the switch Qbeing controlled by the controllerto vary the on period of the switch Q, during which the inductor is charged, for adjusting an output voltage Vtowards a target value V. The controllermonitors at least one of the indication of the voltage across the switch Qand the ratio of the switch on period Tto the switch off period Tfor detecting that the input voltage Vhas a low value.

A method and circuit for correcting a power factor in an alternating current/direct current power transformer. The circuit has an inductor fed by a rectified AC voltage, and a switch by which the inductor can be charged and discharged by closing and opening the switch, and further has a diode by which the discharge current of the inductor is fed to the output of the circuit. During the discharge phase, a voltage corresponding to the output voltage is measured, and the measured values are stored. It is further determined when the discharge current reaches or crosses the zero line at the end of a discharge phase. Switch-on and switch-off signals for actuating the switch are generated by analyzing the information determined. The switch should not be switched on again until a particular minimum switch-off time has been reached.

Method and circuit for power factor correction

The application relates to a circuit for operating a light-emitting means, having a half-bridge or full-bridge circuit for providing a supply voltage for the at least one light-emitting means, and a control circuit for the closed-loop control of the operation of the light-emitting means and/or fault identification. A measurement signal which represents the current through the bridge circuit and/or a measurement signal which represents the lamp current and a measurement signal which represents the voltage across the at least one light-emitting means are supplied to the control circuit at the same input.

Growing community of inventors

Tyne and Wear, United Kingdom

Jamie Kelly