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 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 measurement assembly includes a first light emitter set including a plurality of light emitters arranged at equal intervals in a first direction, the light emitters emitting lights with frequencies different from one another; a light receiver disposed on an object under measurement and configured to receive incident lights from the light emitter set; and a position determination unit configured to determine a first current position of the object under measurement according to frequencies of incident lights currently received by the light receiver from the first light emitter set.

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 measurement assembly includes a first light emitter set including a plurality of light emitters arranged at equal intervals in a first direction, the light emitters emitting lights with frequencies different from one another; a light receiver disposed on an object under measurement and configured to receive incident lights from the light emitter set; and a position determination unit configured to determine a first current position of the object under measurement according to frequencies of incident lights currently received by the light receiver from the first light emitter set.