Patent TW-201031271-A (TW)
Title: Method and circuit arrangement for supplying power to operate at least one gas discharge lamp
Inventor: BRAUN ALOIS
IPC: H05B41/28
Filed: 2009-10-20
Abstract: A method is provided for supplying a power to operate at least one gas discharge lamp (5) according to a dim signal (DIM), which is input into a power factor correction circuit (10) having a switch element (12), that is activated in accordance with a switch time (TON), wherein the power factor correction circuit (10) outputs an intermediate circuit voltage (UZK), that is then input into an inverter (20) to provide the lamp power. In an operation course when the dim signal (DIM) contains neither a leading edge nor a falling edge the power factor correction circuit (10) and the inverter (20) are operated independently by a control circuit for each one. In an operation course when the dim signal (DIM) contains a leading edge or a falling edge the two independent control circuits are coupled with each other through an overbuilt third control circuit, so that the lamp power (Pa) of the inverter (20) can be set make the switch time (TON) of the switch element in the power factor correction circuit (10) equal to a pre-determined time (T1). The present invention also provides a circuit device having: an input terminal for inputting a dim signal (DIM), an output terminal for providing a lamp power (Pa) to operate at least one gas discharge lamp (5), a power factor correction circuit (10) connecting to the input terminal with a controllable timing switch element (12) having a control input terminal, in order to stabilize a uniform current through the circuit device, a inverter (20) connecting to the output terminal for providing the lamp power (Pa), an intermediate circuit voltage (UZK), which is applied to the output end of the power factor correction circuit (10) and to the input end of the inverter (20), and a control unit (40) having a control output terminal for providing a control signal for the power factor correction circuit (10) and a control signal for the inverter (20) at the control output terminal, wherein the circuit device has a first storage element (421) connecting with the control unit for storing a first value representing the magnitude of a first switch time (T1) of the switch element (12), has a detection unit (11) connecting with the input terminal, which is designed to determine, whether the dim signal (DIM) contains a leading edge or a falling edge, in case of detected full wave (neither leading edge nor falling edge), stores the first value, which represents the magnitude of the first switch time (T1) of the switch element, into the first storage element (421), controls the inverter (20), so that a lamp power (Pa) is provided at the output terminal, which is equal to a characteristic power of the gas discharge lamp, and in case of a detected leading edge or a falling edge, reads out the first value for the first switch time (T1) from the storage element and set the lamp power (Pa) through controlling the inverter, so that the switch element (12) of the power factor correction circuit (10) is repeatedly closed for the duration of the switch time (T1).