摘要:
In various embodiments, a device for dimming a light source is provided. The device may include a two-wire power supply line having interposed therein a switch for controlling transfer of the power supply towards the light source; a capacitance located downstream of the switch being traversed by a charge current as the switch is switched on; and a pre-charge stage interposed between the switch and the capacitance; the pre-charge stage being configured to limit to a given value the charge current.
摘要:
A method of compensating the degradation of the luminous intensity due to aging in a light source by controlling a power supply signal of said light source. The method may include: detecting the temperature of said light source; determining a parameter representative of the aging of said light source as a function of said temperature; and varying said power supply signal as a function of said parameter representative of the aging of the light source.
摘要:
In various embodiments, a device for dimming a light source is provided. The device may include a two-wire power supply line having interposed therein a switch for controlling transfer of said power supply towards said light source; a capacitance located downstream of said switch being traversed by a charge current as said switch is switched on; and a pre-charge stage interposed between said switch and said capacitance; said pre-charge stage being configured to limit to a given value said charge current.
摘要:
A circuit arrangement for driving electrical loads such as High Flux (HF) LEDs used as lighting sources. The circuit arrangement includes: a switched power source (10) providing a voltage signal switched with a switching frequency (Fsw) and having a given amplitude (Vout), and a plurality of cells (20) connected to the switched power source (10), wherein the LED cells (20) each include an LC decoupling impedance (50) for defining the intensity of the current flowing into the LED cell (30) from the switched power source (10). The LC decoupling impedance (50) includes LC components defining a resonance frequency (Fres) such that the switching frequency (Fsw) of the switched power source (10) is about one half the resonance frequency (Fres) of the LC decoupling impedance (50), whereby the average intensity of the current flowing into the cell is kept constant irrespective of the load on the LED cell (20).
摘要:
A driving arrangement for feeding a current generated by a high frequency generator (10) coupled with a magnetic element (11) to a plurality of LED cells (33) each including at least one LED. The arrangement includes a respective plurality of LED channels (1, 2, 3, 4; 1′, 2′, 3′, 4′) arranged in a parallel configuration and one or more coupled inductors (L12, L23, L34) the couple in pairs the channels of the plurality of LED channels (1, 2, 3, 4; 1′, 2′, 3′, 4′).
摘要:
A drive arrangement for light sources may include: a connection line to feed a light source, a switch element coupled to said line to apply on/off signals to said line, and a controller to control operation of said switch, said controller being sensitive to at least one of a dimming signal representative of a desired dimming level for said light source and an information-carrying digital signal, wherein said controller is configured to control operation of said switch to: a) PWM modulate an on/off signal applied to said line as a function of said dimming signal, whereby the average current conveyed towards said light source and determined by said PWM modulated on/off signal controls the brightness of said light source, b) transmit said information-carrying digital signal as an on/off information signal applied to said line, whereby the information carried by said information-carrying digital signal is transmitted over said line.
摘要:
A driver arrangement for LEDs may include a PWM controller to deliver a feed voltage between an output line and a ground output line, said controller having a pin, a current regulator to regulate the feed current, a switch to connect said pin to a scaled-down version of the voltage on the first output line, and a control line to receive a signal to produce dimming, said control line coupled to said regulator and said switch to couple said regulator to a reference voltage and control switching, whereby: in one of the levels of a PWM control signal, said regulator interrupts said feed current, the voltage on said ground output line is floating, and in the other levels, said regulator is coupled to said reference voltage, said switch disconnects said pin from said voltage on the output line and the voltage on said ground output line is regulated.
摘要:
A driving arrangement for feeding a current generated by a high frequency generator (10) coupled with a magnetic element (11) to a plurality of LED cells (33) each including at least one LED. The arrangement includes a respective plurality of LED channels (1, 2, 3, 4; 1′, 2′, 3′, 4′) arranged in a parallel configuration and one or more coupled inductors (L12, L23, L34) the couple in pairs the channels of the plurality of LED channels (1, 2, 3, 4; 1′, 2′, 3′, 4′).
摘要:
A circuit for driving LEDs includes: —a transformer with a secondary winding for driving the LEDs and a primary winding, —a half-bridge arrangement fed with an input voltage and coupled to the transformer, —a resonant circuit between the half-bridge arrangement and the primary winding of the transformer, the resonant circuit having a given resonance frequency, and—a controller configured for switching the half-bridge arrangement with a switching frequency variable between first and second values. The second value is closer than the first value to the resonance frequency of the resonant circuit created between the half-bridge arrangement and the primary winding of the transformer. This boosts the voltage fed towards the LEDs via the transformer. The LEDs are preferably included in the form of series of LEDs connected to the secondary winding of the transformer via a rectifier placed outside the housing of the power-supply.
摘要:
A drive arrangement for light sources may include: a connection line to feed a light source, a switch element coupled to said line to apply on/off signals to said line, and a controller to control operation of said switch, said controller being sensitive to at least one of a dimming signal representative of a desired dimming level for said light source and an information-carrying digital signal, wherein said controller is configured to control operation of said switch to: a) PWM modulate an on/off signal applied to said line as a function of said dimming signal, whereby the average current conveyed towards said light source and determined by said PWM modulated on/off signal controls the brightness of said light source, b) transmit said information-carrying digital signal as an on/off information signal applied to said line, whereby the information carried by said information-carrying digital signal is transmitted over said line.