Abstract: In a lighting device, sets of LEDs are employed using the natural characteristics of the LEDs to resemble incandescent lamp behavior when dimmed, thereby obviating the need for sophisticated controls. A first set of at least one LED produces light with a first color temperature, and a second set of at least one LED produces light with a second color temperature. The first set and the second set are connected in series, or the first set and the second set are connected in parallel, possibly with a resistive element in series with the first or the second set. The first set and the second set differ in temperature behavior, or have different dynamic electrical resistance. In various embodiments, the sum of the currents provided to the first and second sets may be substantially equal to a magnitude of an input current.

Abstract: In a lighting device, sets of LEDs are employed using the natural characteristics of the LEDs to resemble incandescent lamp behavior when dimmed, thereby Obviating the need for sophisticated controls. A first set of at least one LED produces light with a first color temperature, and a second set of at least one LED produces light with a second color temperature. The first set and the second set are connected in series, or the first set and the second set are connected in parallel, possibly with a resistive element in series with the first or the second set. The first set and the second set differ in temperature behavior, or have different dynamic electrical resistance. In various embodiments, the sum of the currents provided to the first and second sets may be substantially equal to a magnitude of an input current.

Abstract: In a lighting device, sets of LEDs are employed using the natural characteristics of the LEDs to resemble incandescent lamp behavior when dimmed, thereby obviating the need for sophisticated controls. A first set of at least one LED produces light with a first color temperature, and a second set of at least one LED produces light with a second color temperature. The first set and the second set are connected in series, or the first set and the second set are connected in parallel, possibly with a resistive element in series with the first or the second set. The first set and the second set differ in temperature behavior, or have different dynamic electrical resistance. The light device produces light with a color point parallel and close to a blackbody curve.

Abstract: In a lighting device, sets of LEDs are employed using the natural characteristics of the LEDs to resemble incandescent lamp behavior when dimmed, thereby obviating the need for sophisticated controls. A first set of at least one LED produces light with a first color temperature, and a second set of at least one LED produces light with a second color temperature. The first set and the second set are connected in series, or the first set and the second set are connected in parallel, possibly with a resistive element in series with the first or the second set. The first set and the second set differ in temperature behavior, or have different dynamic electrical resistance. The light device produces light with a color point parallel and close to a blackbody curve.

Abstract: Usually when switched secondary control is used to regulate output voltages in a flyback converter, high peak currents through the secondary switch occur during startup. Traditional soft-start methods cannot be applied to limit these peak currents. With the inventive control circuit and method, current limiting during startup is achieved by measuring the magnetic flux in the fly-back transformer, and by advancing the time instant at which current flow through the secondary switch (11) starts with respect to the end of the flyback stroke in dependence of the magnetic flux in the transformer.

Abstract: The present invention relates to a multiple output flyback converter having a switch regulated output circuit (5). To avoid a second communication interval, due an output voltage in this secondary controlled output that is lower what is implied by its number of winding turns, the inductance of this circuit is increased. This can preferably be done by increasing the leakage inductance of the winding (6) in the regulated circuit.

Abstract: A voltage integrator, comprising a resistor (4) and a capacitor (5) connected in series between an input voltage (V) and ground, wherein the resistance (R) of said resistor and the capacitance (C) of said capacitor are adapted such that a voltage (Vc) across said capacitor approximates the integral of said input voltage (V). Means are provided for preventing said capacitor voltage (Vc) from falling below a lower limit, preferably zero, thereby ensuring automatic initialization of the integrator after each integration cycle.