An embodiment provides a lamp apparatus, including: at least one filament; an amount of amalgam; a heat-sink assembly connected to the lamp apparatus; and at least one control circuit comprising a heating element and a temperature measurement element connected to the at least one filament, wherein the control circuit varies the electrical power delivered to the heating element, thereby controlling an internal temperature of the lamp apparatus relative to a temperature set point. Other aspects are described and claimed.

A light emission control device controls a first switching element of a light source circuit including a first resistor, a light emitting element, and the first switching element coupled in series between a first power supply node and a second power supply node set to a lower potential than the first power supply node. The light emission control device includes a second detection circuit that compares a first potential difference between both ends of the first resistor with a determination value, a light emission control circuit that outputs a first control signal that controls on/off of the first switching element, and a logic determination circuit that determines whether or not the first switching element is short-circuited. The light emission control circuit sets the first control signal to a first drive stoppage state that inactivates the first control signal, and when the second detection circuit has detected that the first potential difference is larger than the determination value, the logic determination circuit outputs an error signal.

A dimmable ballast circuit for a compact fluorescent lamp controls the intensity of a lamp tube in response to a phase-control voltage received from a dimmer switch. The ballast circuit comprises a phase-control-to-DC converter circuit that receives the phase-control voltage, which is characterized by a duty cycle defining a target intensity of the lamp tube, and generates a DC voltage representative of the duty cycle of the phase-control voltage. Changes in the duty cycle of the phase-control voltage that are below a threshold amount are filtered out by the converter circuit, while intentional changes in the duty cycle of the phase-control voltage are reflected in changes in the target intensity level and thereby the intensity level of the lamp tube.

A dimmable ballast circuit for a compact fluorescent lamp controls the intensity of a lamp tube in response to a phase-control voltage received from a dimmer switch. The ballast circuit comprises a phase-control-to-DC converter circuit that receives the phase-control voltage, which is characterized by a duty cycle defining a target intensity of the lamp tube, and generates a DC voltage representative of the duty cycle of the phase-control voltage. Changes in the duty cycle of the phase-control voltage that are below a threshold amount are filtered out by the converter circuit, while intentional changes in the duty cycle of the phase-control voltage are reflected in changes in the target intensity level and thereby the intensity level of the lamp tube.

A light emission control device controls a first switching element of a light source circuit including a first resistor, a light emitting element, and the first switching element coupled in series between a first power supply node and a second power supply node set to a lower potential than the first power supply node. The light emission control device includes a second detection circuit that compares a first potential difference between both ends of the first resistor with a determination value, a light emission control circuit that outputs a first control signal that controls on/off of the first switching element, and a logic determination circuit that determines whether or not the first switching element is short-circuited. The light emission control circuit sets the first control signal to a first drive stoppage state that inactivates the first control signal, and when the second detection circuit has detected that the first potential difference is larger than the determination value, the logic determination circuit outputs an error signal.

A dimmable ballast circuit for a compact fluorescent lamp controls the intensity of a lamp tube in response to a phase-control voltage received from a dimmer switch. The ballast circuit comprises a phase-control-to-DC converter circuit that receives the phase-control voltage, which is characterized by a duty cycle defining a target intensity of the lamp tube, and generates a DC voltage representative of the duty cycle of the phase-control voltage. Changes in the duty cycle of the phase-control voltage that are below a threshold amount are filtered out by the converter circuit, while intentional changes in the duty cycle of the phase-control voltage are reflected in changes in the target intensity level and thereby the intensity level of the lamp tube.

A dimmable ballast circuit for a compact fluorescent lamp controls the intensity of a lamp tube in response to a phase-control voltage received from a dimmer switch. The ballast circuit comprises a phase-control-to-DC converter circuit that receives the phase-control voltage, which is characterized by a duty cycle defining a target intensity of the lamp tube, and generates a DC voltage representative of the duty cycle of the phase-control voltage. Changes in the duty cycle of the phase-control voltage that are below a threshold amount are filtered out by the converter circuit, while intentional changes in the duty cycle of the phase-control voltage are reflected in changes in the target intensity level and thereby the intensity level of the lamp tube.

A lamp system, and a method of operating the lamp system, are provided. The lamp system includes a gas discharge lamp, an electronic ballast and a control unit. A performance influencing control variable of the lamp system is used. The method allows operation with a high emission performance independent of the design thereof and of any potential changes caused by lamp aging and without any knowledge of the optimal operating temperature. According to the invention a light intensity control is provided, in which an actual value of a light intensity emitted by the gas discharge lamp is measured using a light sensor and the emitted light intensity is used as an actuating variable.

A lamp system, and a method of operating the lamp system, are provided. The lamp system includes a gas discharge lamp, an electronic ballast and a control unit. A performance influencing control variable of the lamp system is used. The method allows operation with a high emission performance independent of the design thereof and of any potential changes caused by lamp aging and without any knowledge of the optimal operating temperature. According to the invention a light intensity control is provided, in which an actual value of a light intensity emitted by the gas discharge lamp is measured using a light sensor and the emitted light intensity is used as an actuating variable.

A lamp system, and a method of operating the lamp system, are provided. The lamp system includes a gas discharge lamp, an electronic ballast and a control unit. A performance influencing control variable of the lamp system is used. The method allows operation with a high emission performance independent of the design thereof and of any potential changes caused by lamp aging and without any knowledge of the optimal operating temperature. According to the invention a light intensity control is provided, in which an actual value of a light intensity emitted by the gas discharge lamp is measured using a light sensor and the emitted light intensity is used as an actuating variable.