Abstract: This invention discloses an alternative communication and control path that can by-pass a primary communication and control line in the control luminaires of an illumination network luminaires. By creating the alternative back-up path, it is possible to still communicate and control network elements in cases when the primary communication and control path is unavailable or when direct control of individual or a plurality of luminaries is desired. In one aspect of the invention, this alternative path may provide for a direct interface for demand response utility programs for specialized control of the luminaires of the illumination network.

Abstract: A light source sequentially emits lights generated by at least three light emitting elements each emitting a different primary color to generate an image. Each light emitting element has a duty cycle in a lighting period, which may be an image frame period. A sequence scheme is provided for alternatingly driving different ones of the light emitting elements. The light emitting elements are driven in accordance with the sequence scheme at least two times in the lighting period, while maintaining the duty cycle for each light emitting element. In the sequence scheme, at least one light emitting element having the highest temperature sensitivity of all light emitting elements is driven more times than another one.

Abstract: This invention discloses an alternative communication and control path that can by-pass a primary communication and control line in the control luminaires of an illumination network luminaires. By creating the alternative back-up path, it is possible to still communicate and control network elements in cases when the primary communication and control path is unavailable or when direct control of individual or a plurality of luminaries is desired. In one aspect of the invention, this alternative path may provide for a direct interface for demand response utility programs for specialized control of the luminaires of the illumination network.

Abstract: A light source sequentially emits lights generated by at least three light emitting elements each emitting a different primary color to generate an image. Each light emitting element has a duty cycle in a lighting period, which may be an image frame period. A sequence scheme is provided for alternatingly driving different ones of the light emitting elements. The light emitting elements are driven in accordance with the sequence scheme at least two times in the lighting period, while maintaining the duty cycle for each light emitting element. In the sequence scheme, at least one light emitting element having the highest temperature sensitivity of all light emitting elements is driven more times than another one.

Abstract: A method of electronic ballast protection including providing an electronic ballast having an AC/DC converter 104 with an electronic ballast input and a mains voltage connection 103 connectable to a mains voltage 102, an inverter 120 operably connected to the AC/DC converter 104 and having an electronic ballast output 125 connectable to a lamp 124, a control circuit 116 controlling the inverter 120, and a low voltage power supply 114 providing low voltage power to the control circuit 116; supplying power to the low voltage power supply 114 from the electronic ballast input when the mains voltage connection 103 is wired to mains voltage 102; and disconnecting the power to the low voltage power supply 114 when the electronic ballast output 125 is wired to the mains voltage 102.

Abstract: A gas discharge lamp is driven using a high frequency lamp current. A lamp driving circuit comprises a high frequency bridge circuit for supplying said lamp current. To prevent the lamp from extinguishing, when the lamp voltage is lower than a predetermined lamp operation voltage, a resonant circuit is provided in the lamp driving circuit between the lamp and the high frequency bridge circuit. The frequency of the bridge circuit is selected such that the resonant circuit may resonate to sweep up the voltage supplied to the gas discharge lamp to a voltage higher than said lamp operation voltage.

Abstract: A method of electronic ballast protection including providing an electronic ballast having an AC/DC converter 104 with an electronic ballast input and a mains voltage connection 103 connectable to a mains voltage 102, an inverter 120 operably connected to the AC/DC converter 104 and having an electronic ballast output 125 connectable to a lamp 124, a control circuit 116 controlling the inverter 120, and a low voltage power supply 114 providing low voltage power to the control circuit 116; supplying power to the low voltage power supply 114 from the electronic ballast input when the mains voltage connection 103 is wired to mains voltage 102; and disconnecting the power to the low voltage power supply 114 when the electronic ballast output 125 is wired to the mains voltage 102.

Abstract: A method for dimming a gas discharge lamp, such as an HID lamp including an MH lamp, includes operating the lamp at nominal power with commutating DC current having a current magnitude IL=?Inom, ? being equal to 1 or less than 1. The current magnitude IL is reduced, but the lamp still is operated at commutating DC current, until ? reaches a predetermined value ?. Then, the lamp is operated at DC current, and the current magnitude is reduced further, thus achieving a lower dimming level.

Abstract: A switch mode power supply for igniting and operating a high-pressure gas discharge lamp includes an ignition sub-circuit which is coupled via a transformer to the circuit. The ignition sub-circuit has at least an ignition capacitor, and a switching element for discharging the capacitor at a desired moment in time having a control electrode. The control electrode of the switching element is connected to the commutator of the lamp circuit via a control sub-circuit having substantially passive elements.

Abstract: The invention relates to a circuit for operating a high-pressure discharge lamp, which circuit is provided with means for operating the connected lamp in a dimmed state by means of a dimming signal Ds. The circuit is provided with: input terminals for connecting the circuit to a power supply source, output terminals for connecting the lamp to be operated, a switch-mode power supply (smps) having a converter provided with a semiconductor switch for generating a converter output voltage across buffer capacitor means, and a control circuit for generating a control signal in dependence on the dimming signal Ds for controlling the semiconductor switch. According to the invention, the circuit is further provided with means for generating a converter output voltage-related signal Lvs for monitoring stable lamp operation by limiting the dimmed state by means of the control circuit.

Abstract: A circuit for operating a high-pressure discharge lamp with successive current periods, which circuit is provided with means for operating the connected lamp by means of a dimming signal Ds from a first state to a second state, which circuit is further provided with: input terminals for connecting the circuit to a power supply source, output terminals for connecting the lamp to be operated, a switch-mode power supply (smps) having a converter with a semiconductor switch for generating a converter output voltage across buffer capacitor means having a capacitance, and a control circuit for generating a control signal which is intended to control the switch and depends on the dimming signal. The circuit is provided with means for adjusting the capacitance of the buffer capacitor means.

Abstract: A switching device intended for igniting and operating a high-pressure discharge lamp, provided with a switch-mode power supply (smps) for supplying a controlled current to the lamp, and with a pre-conditioner for feeding the smps. The pre-conditioner is provided with a storage capacitor. The switching device also includes an ignition circuit including a pulse capacitor and a switch for generating ignition-voltage pulses for igniting the lamp. The pulse capacitor, having a capacity of CF, is energized from the storage capacitor via an ohmic resistor.

Abstract: The invention relates to a circuit for operating a high-pressure discharge lamp, which circuit is provided with means for operating the connected lamp in a dimmed state by means of a dimming signal Ds.

Abstract: The invention relates to a circuit for operating a high-pressure discharge lamp with successive current periods, which circuit is provided with means for operating the connected lamp by means of a dimming signal Ds from a first state to a second state, which circuit is further provided with:

Abstract: The invention relates to a switching device intended for igniting and operating a high-pressure discharge lamp, provided with a switch-mode power supply (smps) for supplying a controlled current to the lamp, and with a pre-conditioner for feeding the smps. Said pre-conditioner is provided with a storage capacitor. The switching device also comprises an ignition circuit including a pulse capacitor and a switch for generating ignition-voltage pulses for igniting the lamp. The pulse capacitor having a capacity of CF is energized from the storage capacitor via an ohmic resistor with a value of R Ohm. According to the invention, the product RC is at most 1031 2.