Drivers (1-7) comprise respective switching circuits (1, 2) for guiding respective current signals during respective time-intervals for the sequential driving of light emitting circuits (91, 92). The respective time-intervals are defined by the fact that amplitudes of a mains signal are in respective ranges during the respective time-intervals. More specifically, there is a bypass switching circuit (5) for guiding a bypass current signal which bypasses all light emitting circuit (91, 92) during an initial time-interval. An adaptation circuit (6, 7) adapts amplitudes of the respective current signals during the respective time-intervals, to reduce a total harmonic distortion. Said adapting may comprise an adaptation in response to information derived from the amplitude of the mains signal, and may comprise shaping the amplitudes of the current signals in response to information derived from the amplitude of the mains signal. Preferably, the shaped amplitudes of the respective current signals will be substantially identical to shapes of the amplitude of the mains signal in the respective ranges. The adaptation circuit (6, 7) may comprise a current source (6) and a definition circuit (7).

A light-emitting diode driving module includes an LED driving circuit to activate light-emitting diodes driven by a rectified voltage, and to adjust driving current conducted through driving nodes to the light-emitting diodes depending on a voltage of a driving current setting node; and a driving current controller to control the voltage of the driving current setting node by outputting a driving current control signal. The driving current controller includes a control signal output circuit connected to a dimming node to receive a dimming signal when the rectified voltage is modulated, and to adjust the driving current control signal depending on the dimming signal; a mode detector to detect whether the rectified voltage is modulated by receiving a source voltage depending on the rectified voltage, and to enable a selection signal depending on a detection result; and a power compensator to adjust the driving current control signal when the selection signal is enabled.

A control algorithm for operating a fluid disinfecting system by UV radiation, wherein the UV radiation is generated by at least one UV lamp including a pair of heating cathodes having a discharge voltage (U.sub.D), the UV lamp is operated by an electronic ballast unit equipped with the control algorithm for adjusting the UV power of the UV lamp by pulse-width-modulation to reduce UV power. The control algorithm decreases the current to a level (I.sub.kmin), increases the voltage amplitude (U) above the discharge voltage (U.sub.D) until a desired UV power level is reached. The pulse width (PW) is decreased with increasing voltage amplitude (U) until PW.sub.min is reached. The decrease in current and the increase in voltage generate an ineffective current-voltage-ratio in which excess current heats the cathode. An electronic ballast equipped with the algorithm and systems equipped with such ballasts are also disclosed.

A multi-channel dual-mode digital control LED driving circuit and an LED lamp. The driving circuit comprises a current sampling module (10), a comparison and detection module (30), a digital control module (40) and a constant current control module (20). By means of feeding back an adjustment current for the load (70) by the digital control module (40), and feeding back and adjusting a current of the load (70) in real time by the constant current control module (20), the driving circuit adjusts the load (70) in real time, so that dual-mode cooperation working is realized, and thus a response speed is greatly improved, the accuracy of an output voltage and the current of the load (70) is improved, and at the same time, the system stability is enhanced and wide universality is achieved.

A light-emitting diode driving module includes an LED driving circuit to activate light-emitting diodes driven by a rectified voltage, and to adjust driving current conducted through driving nodes to the light-emitting diodes depending on a voltage of a driving current setting node; and a driving current controller to control the voltage of the driving current setting node by outputting a driving current control signal. The driving current controller includes a control signal output circuit connected to a dimming node to receive a dimming signal when the rectified voltage is modulated, and to adjust the driving current control signal depending on the dimming signal; a mode detector to detect whether the rectified voltage is modulated by receiving a source voltage depending on the rectified voltage, and to enable a selection signal depending on a detection result; and a power compensator to adjust the driving current control signal when the selection signal is enabled.

Drivers (1-7) comprise respective switching circuits (1, 2) for guiding respective current signals during respective time-intervals for the sequential driving of light emitting circuits (91, 92). The respective time-intervals are defined by the fact that amplitudes of a mains signal are in respective ranges during the respective time-intervals. More specifically, there is a bypass switching circuit (5) for guiding a bypass current signal which bypasses all light emitting circuit (91, 92) during an initial time-interval. An adaptation circuit (6, 7) adapts amplitudes of the respective current signals during the respective time-intervals, to reduce a total harmonic distortion. Said adapting may comprise an adaptation in response to information derived from the amplitude of the mains signal, and may comprise shaping the amplitudes of the current signals in response to information derived from the amplitude of the mains signal. Preferably, the shaped amplitudes of the respective current signals will be substantially identical to shapes of the amplitude of the mains signal in the respective ranges. The adaptation circuit (6, 7) may comprise a current source (6) and a definition circuit (7).

A control algorithm for operating a fluid disinfecting system by UV radiation, wherein the UV radiation is generated by at least one UV lamp including a pair of heating cathodes having a discharge voltage (U.sub.D), the UV lamp is operated by an electronic ballast unit equipped with the control algorithm for adjusting the UV power of the UV lamp by pulse-width-modulation to reduce UV power. The control algorithm decreases the current to a level (I.sub.kmin), increases the voltage amplitude (U) above the discharge voltage (U.sub.D) until a desired UV power level is reached. The pulse width (PW) is decreased with increasing voltage amplitude (U) until PW.sub.min is reached. The decrease in current and the increase in voltage generate an ineffective current-voltage-ratio in which excess current heats the cathode. An electronic ballast equipped with the algorithm and systems equipped with such ballasts are also disclosed.

A processor controlled induction RF fluorescent lamp, where the control processor runs a load control algorithm at least for switching the electrical load for connection to an external dimming device, the lamp comprising a vitreous envelope filled with an ionizable gas mixture; a power coupler comprising at least one winding of an electrical conductor; and an electronic ballast providing appropriate voltage and current to the power coupler.

An electronic device adapted for adjusting a light effect of a CCFL is provided. The electronic device is electronically connected to the CCFL. The electronic device comprises a PWM controller configured to receive at least a digital signal and to output a specific-frequency reference signal according to the digital signal, a driver electronically connected to the PWM controller and configured to output a first voltage signal according to the specific-frequency reference signal, and a transformer electronically connected to the driver and the CCFL. The transformer amplifies the first voltage signal to generate a second voltage signal and sends the second voltage signal to the CCFL. A light effect is generated by the CCFL according to the second voltage signal.

A discharge lamp driving device includes: a discharge lamp driving unit which supplies drive power to a discharge lamp; and a control unit which controls the discharge lamp driving unit according to a waveform of the drive power. The waveform has n launching periods and a low-power mode lighting period. The n launching periods include a first launching period in which the drive power increases toward refresh power that is equal to or above drive power in a low-power mode and equal to or below rated power, and (n1) launching periods in which the drive power is maintained at the refresh power. The control unit, in an x-th launching period, supplies the discharge lamp with a drive current having a drive frequency equal to or below a drive frequency of a drive current supplied to the discharge lamp in an (x1)th launching period.