Abstract: The present invention relates to a driving circuit (100) connected to a conventional phase-cut dimmer. A LED light source (30) is driven by a switched mode power supply (26), which is powered by the mains voltage through a phase-cut dimmer (10) and a rectifier (22). The current through the LED light source (30) is reduced according to the voltage level of the average rectified voltage Vin detected by a voltage sensor (24) and the on time limitation of the switched mode power supply (26). The current amplitude will be increasingly reduced towards the low voltage levels of Vin, namely towards the low dimmer knob levels. Thereby, the invention allows a LED light source driving circuit (100) connected to a conventional phase-cut dimmer to readily make the dimming curve of the LED light source (30) non-linear for being more compatible with the human eye sensitivity.

Abstract: A switch module is designed to facilitate user definition of a group of switch modules that control the same lamp. A lamp unit (12) containing the lamp responds selectively to messages from the switch modules (10, 10?) when the messages comprise ID information matching with ID information stored in the lamp unit (12). A group is formed by detecting user control operation of sensors (100) in the switch modules (10, 10?), transmitting messages from the switch modules (10, 10?) in response and determining from the messages whether the switch modules (10?) have both been operated within a time interval with a duration of less than a predetermined threshold. If so, the ID information value in memories (104) of the switch module (10) and/or the further switch module (10?) are set to matching ID values, for use in the messages to control the lamp unit.

Abstract: A lamp is provided that is controlled by messages transmitted via a network. The lamp has an internal memory that stores an address and an internal control circuit that responds to received messages that refer to this address. The address is updated when the lamp is installation in a power supply socket, using for example an address from the first message that is transmitted after installation. The lamp contains a detector that detects disconnection of the lamp from the power supply socket, for example by monitoring a resistance value between two parts of one of the power supply terminals of the lamp. In response to this detection the control circuit of the lamp sets information that enables an update of the address in the memory. When it is detected that the lamp is again connected to a power supply socket the address is updated on condition that the update is enabled.

Abstract: A method is disclosed of controlling a LED, comprising driving the LED with a DC current for a first time, interrupting the DC current for a second time such that the first time and the second time sum to a period, determining at least one characteristic of the LED while the DC current is interrupted, and controlling the DC current during a subsequent period in dependence on the at least one characteristic. The invention thus benefits from the simplicity of DC operation. By operating at the LED in a DC mode, rather than say in a PWM mode, the requirement to be able to adjust the duty cycle is avoided. By including interruptions to the DC current, it is possible to utilize the LED itself to act as a sensor in order to determine a characteristic of the LED. The need for additional sensors is thereby avoided.

Abstract: A circuit for connecting to a dimmer, the circuit configured to receive an input signal from the dimmer. The circuit comprises a first load and a switch. The switch is operable to automatically engage the first load at a predetermined time from a zero-crossing of the input signal and automatically disengage the first load at other times.

Abstract: A method of controlling an electronic ballast for a lighting circuit, the ballast including a bleeder, for use with dimmer circuits, by, in response to a mains supply being connected to the lighting circuit, determining whether a dimmer circuit is present in the lighting circuit; and in response to determining a dimmer circuit is not present, disconnecting the bleeder from the lighting circuit at least until the mains supply is disconnected. The method may be used during start, and the determination of whether a dimmer circuit is present is stored at least until the mains supply is disconnected. Determination of either a leading or trailing edge phase cut dimmer may be made by looking for deviation from the expected sine-wave voltage, either directly through temporal or voltage deviation, or indirectly by examining the second differential of the voltage with respect to time.

Abstract: A surge protection circuit is disclosed for an electrical Load which may be for instance an LED load which is directly connected to a supply such as mains supply, and comprises a plurality of switches which are distributed across a plurality of semiconductor die. A surge detector detects the start of a spike in the supply, which results from, for example the commencement or interruption of a nearby inductive load, and opens all the switches. By distributing the switches across multiple die the peak voltage across each is reduced relative to using a single die; thereby each die can stay within the absolute maximum voltage capacity. Each die may have its own surge detector; alternatively, a single surge detector may be used which communicates with the switches on each of the die. In an extension the bridge rectifier may be integrated into the circuit distributed across the die. In this embodiment additional inter-die clamping diodes are required to prevent unsafe floating of the edge connections of each die.

Abstract: A controller and a method for controlling lamp drivers such as e.g. LED drivers for lamps having a fast response behavior such as e.g. LED lamps are proposed. They enable to substantially reduce or prevent a visible luminance flicker at such lamps when dimming the lamps with a conventional dimmer such as e.g. a phase cut dimmer. This can be achieved by switching off the lamp driver prematurely in such a way that a time jitter of a dimmer switching does not influence an on-time of the lamp driver. No bulky or expensive filters or capacitors are needed. Thus, a space-switch saving and/or inexpensive construction is enabled.

Abstract: A switch module is designed to facilitate user definition of a group of switch modules that control the same lamp. A lamp unit (12) containing the lamp responds selectively to messages from the switch modules (10, 10?) when the messages comprise ID information matching with ID information stored in the lamp unit (12). A group is formed by detecting user control operation of sensors (100) in the switch modules (10, 10?), transmitting messages from the switch modules (10, 10?) in response and determining from the messages whether the switch modules (10?) have both been operated within a time interval with a duration of less than a predetermined threshold. If so, the ID information value in memories (104) of the switch module (10) and/or the further switch module (10?) are set to matching ID values, for use in the messages to control the lamp unit.

Abstract: A method of controlling an electronic ballast for a lighting circuit, the ballast including a bleeder, for use with dimmer circuits, by, in response to a mains supply being connected to the lighting circuit, determining whether a dimmer circuit is present in the lighting circuit; and in response to determining a dimmer circuit is not present, disconnecting the bleeder from the lighting circuit at least until the mains supply is disconnected. The method may be used during, and the determination of whether a dimmer circuit is present is stored at least until the mains supply is disconnected. Determination of either a leading or trailing edge phase cut dimmer may be made by looking for deviation from the expected sine-wave voltage, either directly through temporal or voltage deviation, or indirectly by examining the second differential of the voltage with respect to time.

Abstract: A lamp is provided that is controlled by messages transmitted via a network. The lamp has an internal memory that stores an address and an internal control circuit that responds to received messages that refer to this address. The address is updated when the lamp is installation in a power supply socket, using for example an address from the first message that is transmitted after installation. The lamp contains a detector that detects disconnection of the lamp from the power supply socket, for example by monitoring a resistance value between two parts of one of the power supply terminals of the lamp. In response to this detection the control circuit of the lamp sets information that enables an update of the address in the memory. When it is detected that the lamp is again connected to a power supply socket the address is updated on condition that the update is enabled.

Abstract: A circuit for connecting to a dimmer, the circuit configured to receive an input signal from the dimmer. The circuit comprises a first load and a switch. The switch is operable to automatically engage the first load at a predetermined time from a zero-crossing of the input signal and automatically disengage the first load at other times.

Abstract: A method is disclosed of controlling a LED, comprising driving the LED with a DC current for a first time, interrupting the DC current for a second time such that the first time and the second time sum to a period, determining at least one characteristic of the LED whilst the DC current is interrupted, and controlling the DC current during a subsequent period in dependence on the at least one characteristic. The invention thus benefits from the simplicity of DC operation. By operating at the LED in a DC mode, rather than say in a PWM mode, the requirement to be able to adjust the duty cycle is avoided. By including interruptions to the DC current, it is possible to utilise the LED itself to act as a sensor in order to determine a characteristic of the LED. The need for additional sensors is thereby avoided.

Abstract: A surge protection circuit is disclosed for an electrical Load which may be for instance an LED load which is directly connected to a supply such as mains supply, and comprises a plurality of switches which are distributed across a plurality of semiconductor die. A surge detector detects the start of a spike in the supply, which results from, for example the commencement or interruption of a nearby inductive load, and opens all the switches. By distributing the switches across multiple die the peak voltage across each is reduced relative to using a single die; thereby each die can stay within the absolute maximum voltage capacity. Each die may have its own surge detector; alternatively, a single surge detector may be used which communicates with the switches on each of the die. In an extension the bridge rectifier may be integrated into the circuit distributed across the die. In this embodiment additional inter-die clamping diodes are required to prevent unsafe floating of the edge connections of each die.

Abstract: The present invention relates to a driving circuit (100) connected to a conventional phase-cut dimmer. A LED light source (30) is driven by a switched mode power supply (26), which is powered by the mains voltage through a phase-cut dimmer (10) and a rectifier (22). The current through the LED light source (30) is reduced according to the voltage level of the average rectified voltage Vin detected by a voltage sensor (24) and the on time limitation of the switched mode power supply (26). The current amplitude will be increasingly reduced towards the low voltage levels of Vin, namely towards the low dimmer knob levels. Thereby, the invention allows a LED light source driving circuit (100) connected to a conventional phase-cut dimmer to readily make the dimming curve of the LED light source (30) non-linear for being more compatible with the human eye sensitivity.

Abstract: A controller and a method for controlling lamp drivers such as e.g. LED drivers for lamps having a fast response behavior such as e.g. LED lamps are proposed. They enable to substantially reduce or prevent a visible luminance flicker at such lamps when dimming the lamps with a conventional dimmer such as e.g. a phase cut dimmer. This can be achieved by switching off the lamp driver prematurely in such a way that a time jitter of a dimmer switching does not influence an on-time of the lamp driver. No bulky or expensive filters or capacitors are needed. Thus, a space-switch saving and/or inexpensive construction is enabled.