A dimmable solid state lighting apparatus can include a plurality of light emitting diode (LED) segments including a first LED segment that can have a targeted spectral power distribution for light emitted from the apparatus that is different than spectral power distributions for other LED segments included in the plurality of LED segments. An LED segment selection circuit can be configured to selectively control current through the plurality of LED segments to shift the light emitted by the apparatus to the targeted spectral power distribution responsive to dimming input.

An auxiliary power system for powering an auxiliary circuit is connected to the same power source that powers the lighting element within a luminaire. The auxiliary power system may be connected to the output of the power source in series or in parallel with the lighting element. The power source may be an LED driver and the lighting element may include one or more LEDs or the power source may be an electronic ballast and the lighting element may be one or more fluorescent lamps.

An auxiliary power system for powering an auxiliary circuit is connected to the same power source that powers the lighting element within a luminaire. The auxiliary power system may be connected to the output of the power source in series or in parallel with the lighting element. The power source may be an LED driver and the lighting element may include one or more LEDs or the power source may be an electronic ballast and the lighting element may be one or more fluorescent lamps.

Realizing a constant-current control even in a stable state of a lamp without increasing a rated output of a power supply. In a stable state of the lamp in which a change value of a lamp voltage after a discharge lamp is turned on becomes less than a certain value, when the lamp voltage rises, a discharge lamp lighting control apparatus changes a current command value to perform a constant-current control. This change is a change from a first current command value at the time when the discharge lamp is turned on to a second current command value that is smaller than the former by a predetermined value. Using this second current command value, the constant-current control is performed. Even after that, the second current command value is changed to a smaller value every time the lamp voltage rises, and the constant-current control is performed using the second current command value.

Realizing a constant-current control even in a stable state of a lamp without increasing a rated output of a power supply. In a stable state of the lamp in which a change value of a lamp voltage after a discharge lamp is turned on becomes less than a certain value, when the lamp voltage rises, a discharge lamp lighting control apparatus changes a current command value to perform a constant-current control. This change is a change from a first current command value at the time when the discharge lamp is turned on to a second current command value that is smaller than the former by a predetermined value. Using this second current command value, the constant-current control is performed. Even after that, the second current command value is changed to a smaller value every time the lamp voltage rises, and the constant-current control is performed using the second current command value.

Described herein is a module for controlling a switching converter, which includes at least one inductor element and one switch element and generates an output electric quantity starting from an input electric quantity. The control module generates a command signal for controlling the switching of the switch element and includes an estimator stage, which generates an estimation signal proportional to the input electric quantity, on the basis of the command signal and of an input signal indicating a time interval in which the inductor element is demagnetized. The control module generates the command signal on the basis of the estimation signal.

A projection device for projecting at least one image onto a projection surface is provided. According to the present disclosure, a control device of the projection device is designed, on the basis of an evaluation of at least one measured value of a measuring device of the projection device determined during a drive of a discharge lamp of the projection device with a current waveform to be checked, to check the current waveform in respect of its suitability for minimizing an electrode burn-back of a first electrode and a second electrode, and in the case of a positive check result, to retain the checked current waveform, and in the case of a negative check result, depending on a checked commutation vector characterizing the checked current waveform, to create, by means of a specifiable algorithm, a modified commutation vector that characterizes a modified current waveform.

A projection device for projecting at least one image onto a projection surface is provided. According to the present disclosure, a control device of the projection device is designed, on the basis of an evaluation of at least one measured value of a measuring device of the projection device determined during a drive of a discharge lamp of the projection device with a current waveform to be checked, to check the current waveform in respect of its suitability for minimizing an electrode burn-back of a first electrode and a second electrode, and in the case of a positive check result, to retain the checked current waveform, and in the case of a negative check result, depending on a checked commutation vector characterizing the checked current waveform, to create, by means of a specifiable algorithm, a modified commutation vector that characterizes a modified current waveform.

A discharge lamp driving device includes a discharge lamp driving unit configured to supply a driving current to a discharge lamp, and a control unit configured to control the discharge lamp driving unit. The discharge lamp driving device is configured to provide a first hybrid period and a second hybrid period each alternately including a first AC period in which an AC current is supplied and a first DC period in which a DC current with a first polarity is supplied. The control unit, in the first hybrid period, is configured to change a ratio of length of the first DC period to length of the first AC period to be increased, and in the second hybrid period, is configured to change a ratio of the length of the first AC period to the length of the first DC period to be increased.

A discharge lamp driving device includes a discharge lamp driving unit configured to supply a driving current to a discharge lamp, and a control unit configured to control the discharge lamp driving unit. The discharge lamp driving device is configured to provide a first hybrid period and a second hybrid period each alternately including a first AC period in which an AC current is supplied and a first DC period in which a DC current with a first polarity is supplied. The control unit, in the first hybrid period, is configured to change a ratio of length of the first DC period to length of the first AC period to be increased, and in the second hybrid period, is configured to change a ratio of the length of the first AC period to the length of the first DC period to be increased.