Tridonicatco Gmbh & Co Kg

Tridonic Bauelemente Gmbh

G&uuml;nter Marent

Stefan Zudrell-Koch

Stefan Koch

An electronic ballast for at least one gas discharge lamp (LA) comprises a rectifier circuit ( ) connectable to an a.c. voltage source (U ), a smoothing circuit ( ), connected to the output of the rectifier circuit ( ), for generating an intermediate circuit voltage (U ), and an inverter ( ) fed with the intermediate circuit voltage (U ), at the output of which inverter a connection for the load circuit ( ) containing the lamp (LA) is connected. The smoothing circuit ( ) is constituted by a switching regulator and the ballast further has a control circuit ( ) which detects the intermediate circuit voltage (U ) and controls a controllable switch (S ) of the switching regulator in dependence upon the value of the intermediate circuit voltage (U ). In order to suppress the occurrence of harmonics and disruptive frequencies the control circuit ( ) further detects an input voltage (U ) of the smoothing circuit ( ) and extends the on-state times for the controllable switch (S ) when the input voltage (U ) approaches its minimal value.

Electronic ballast with intermediate circuit regulation

An electronic ballast for at least one low-pressure discharge lamp contains an inverter which is connected to a direct-voltage source (U ), a load circuit which is connected to the inverter and contains the lamp (LA) and a series resonant circuit, and an evaluating circuit arrangement (M ) which reacts to different operating states of the lamp (LA) and in the case of a defect or removal of the lamp (LA) generates corresponding signals for switching off the inverter. A heating transformer, for heating the coils (W W ), the primary winding (Tp) of which is connected in series with a switch (S ) to the output of the inverter and in any case is connected to the direct-voltage source (U ) if the inverter is switched off on account of the heating-coil defect or the removal of the lamp (LA), with the switch (S ) being clocked in this off-phase.

Growing community of inventors

Dornbirn, Austria

Günter Marent

Growing community of inventors

Dornbirn, Austria

G&uuml;nter Marent

Günter Marent