One embodiment of the invention relates to a system for operating a plurality of streetlights in response to motion from a vehicle. The system includes a sensor associated with at least one of the streetlights and configured to detect the presence of a moving vehicle and to provide a signal representative of the moving vehicle. The system further includes a radio frequency transceiver associated with each of the streetlights. The system yet further includes processing electronics configured to receive the signal representative of the moving vehicle from the sensor and to cause the radio frequency transceiver to transmit a command to one or more of the plurality of the streetlights to change lighting states along a pathway for the vehicle.

One embodiment of the invention relates to a system for operating a plurality of streetlights in response to motion from a vehicle. The system includes a sensor associated with at least one of the streetlights and configured to detect the presence of a moving vehicle and to provide a signal representative of the moving vehicle. The system further includes a radio frequency transceiver associated with each of the streetlights. The system yet further includes processing electronics configured to receive the signal representative of the moving vehicle from the sensor and to cause the radio frequency transceiver to transmit a command to one or more of the plurality of the streetlights to change lighting states along a pathway for the vehicle.

Provided is a system for reducing power consumption in digitally addressable lighting interfaces (DALI), the system including a processor having at least one pin, a transistor coupled to the processor and a resistive network coupled to the processor and the resistive network.

An illumination device described herein includes at least a phosphor converted LED, which is configured for emitting illumination for the illumination device, a first photodetector and a second photodetector. A spectrum of the illumination emitted from the phosphor converted LED comprises a first portion having a first peak emission wavelength and a second portion having a second peak emission wavelength, which differs from the first peak emission wavelength. The first photodetector has a detection range, which is configured for detecting only the first portion of the spectrum emitted by the phosphor converted LED. The second photodetector has a detection range, which is configured for detecting only the second portion of the spectrum emitted by the phosphor converted LED. Methods are provided herein for calibrating and controlling each portion of the phosphor converted LED spectrum, as if the phosphor converted LED were two separate LEDs.

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 discharge lamp lighting device includes a control unit adapted to control a frequency of the AC electric current supplied to a discharge lamp by a feeding unit, in different manners within a first term and a second term which are alternately repeated, the control unit is adapted to control the frequency of the AC electric current such that, within the first term, the frequency of the AC electric current becomes at least one frequency out of plural set frequencies, and is further adapted to control the frequency of the AC electric current, based on a predetermined frequency and an electric current within the previous first term, such that, within the second term, the frequency of the AC electric current becomes a frequency lower than this predetermined frequency.

A discharge lamp lighting device includes a control unit adapted to control a frequency of the AC electric current supplied to a discharge lamp by a feeding unit, in different manners within a first term and a second term which are alternately repeated, the control unit is adapted to control the frequency of the AC electric current such that, within the first term, the frequency of the AC electric current becomes at least one frequency out of plural set frequencies, and is further adapted to control the frequency of the AC electric current, based on a predetermined frequency and an electric current within the previous first term, such that, within the second term, the frequency of the AC electric current becomes a frequency lower than this predetermined frequency.

A discharge lamp driving device includes a discharge lamp driving section configured to supply a driving current to a discharge lamp including a first electrode and a second electrode and a control section configured to control the discharge lamp driving section. The control section is configured to repeat a unit period. The unit period includes a direct current period including a first direct current period in which a direct current having a first polarity is supplied to the discharge lamp and a second direct current period in which a direct current having a second polarity is supplied to the discharge lamp, and an alternating current period provided between the first direct current period and the second direct current period, an alternating current being supplied to the discharge lamp in the alternating current period. The control section is configured to temporally change length of the direct current period.

A discharge lamp driving device includes a discharge lamp driving section configured to supply a driving current to a discharge lamp including a first electrode and a second electrode and a control section configured to control the discharge lamp driving section. The control section is configured to repeat a unit period. The unit period includes a direct current period including a first direct current period in which a direct current having a first polarity is supplied to the discharge lamp and a second direct current period in which a direct current having a second polarity is supplied to the discharge lamp, and an alternating current period provided between the first direct current period and the second direct current period, an alternating current being supplied to the discharge lamp in the alternating current period. The control section is configured to temporally change length of the direct current period.

In a discharge lamp driving device, a mixed period is provided, in which a first period in which an alternating current is supplied and a second period in which a direct current is supplied are alternately repeated and a third period alternately including a first direct current period and a second direct current period in which a direct current having a polarity opposite to a polarity of the direct current in the first direct current period is supplied. Length of the second direct current period is smaller than 0.5 ms. A total of lengths of the first direct current periods in the third period is larger than length of the second period. The third period is not provided at least when the inter-electrode voltage is smaller than a first predetermined value or when a cumulative lighting time of the discharge lamp is smaller than a second predetermined value.