A multi-channel dual-mode digital control LED driving circuit and an LED lamp. The driving circuit comprises a current sampling module (10), a comparison and detection module (30), a digital control module (40) and a constant current control module (20). By means of feeding back an adjustment current for the load (70) by the digital control module (40), and feeding back and adjusting a current of the load (70) in real time by the constant current control module (20), the driving circuit adjusts the load (70) in real time, so that dual-mode cooperation working is realized, and thus a response speed is greatly improved, the accuracy of an output voltage and the current of the load (70) is improved, and at the same time, the system stability is enhanced and wide universality is achieved.

A multi-channel dual-mode digital control LED driving circuit and an LED lamp. The driving circuit comprises a current sampling module (10), a comparison and detection module (30), a digital control module (40) and a constant current control module (20). By means of feeding back an adjustment current for the load (70) by the digital control module (40), and feeding back and adjusting a current of the load (70) in real time by the constant current control module (20), the driving circuit adjusts the load (70) in real time, so that dual-mode cooperation working is realized, and thus a response speed is greatly improved, the accuracy of an output voltage and the current of the load (70) is improved, and at the same time, the system stability is enhanced and wide universality is achieved.

Various embodiments provide a projection arrangement. The projection arrangement may include a discharge lamp; and a ballast for the discharge lamp. The ballast is designed to provide, during operation of the projection arrangement, a lamp current in the form of alternating current and having an average frequency and a preset waveform, which has a preset commutation scheme, to the discharge lamp. The preset commutation scheme is preset by a preset time sequence of commutations of the lamp current. The ballast is designed to provide the lamp current in such a way that the preset commutation scheme of the lamp current is deviated from repeatedly with at least one preset intervening time period by at least one DC phase with a preset time duration.

A light source device includes a light source unit having a dielectric barrier discharge lamp and a lighting circuit. The lighting circuit includes a transformer; a switching element; a controller for the switching element; a detector that detects current flowing through or voltage on a primary or a secondary side of the transformer; and a determination unit. The controller is configured to enable performing a steady-state operation of controlling ON/OFF of the switching element at a steady-state operation frequency (f1) to steadily light the dielectric barrier discharge lamp; and a determination operation of controlling ON/OFF of the switching element at a determination operation frequency (f2) higher than the steady-state operation frequency (f1), and the determination unit determines whether or not to stop the lighting operation based on the current or the voltage detected by the detector when the controller controls the switching element at the determination operation frequency (f2).

A light source device includes a light source unit having a dielectric barrier discharge lamp and a lighting circuit. The lighting circuit includes a transformer; a switching element; a controller for the switching element; a detector that detects current flowing through or voltage on a primary or a secondary side of the transformer; and a determination unit. The controller is configured to enable performing a steady-state operation of controlling ON/OFF of the switching element at a steady-state operation frequency (f1) to steadily light the dielectric barrier discharge lamp; and a determination operation of controlling ON/OFF of the switching element at a determination operation frequency (f2) higher than the steady-state operation frequency (f1), and the determination unit determines whether or not to stop the lighting operation based on the current or the voltage detected by the detector when the controller controls the switching element at the determination operation frequency (f2).

A two-wire load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

Disclosed are systems and methods for adjusting environmental conditions based on automatically and manually generated requests. A commissioned unit comprising at least one IP luminaire (140, 150), transmits a signal comprising one or more identification codes. The signal may be, for example, a coded light signal. An environment control device (160) receives the signal, detects user input indicating one or more preferred environmental conditions, and transmits an environment control request comprising the one or more preferred environmental conditions. An environment manager module (110) receives the environment control request, generates an environment control command using the control request, and transmits the environment control command to one or more commissioned units to alter environmental conditions in a space in accordance with the user input.

A zero-crossing detection method, and devices incorporating the method, enable a selectively enabled bias to pull-up a zero-crossing signal, thereby enabling monitoring of the zero-crossing of both half-cycles of the alternating current (AC). This improves synchronization of the device in noisy environments and enables the detection of dimming problems during either half-cycle. Aspects can detect improper dimmer firing events on either polarity of the power cycle and restore normal dimmer operations when needed.

A control method of an electronic ballast of a gas discharge lamp (HID), to generate a PWM1 signal for controlling on/off of a left upper arm switch, a PWM2 signal for controlling on/off of a right upper arm switch, a PWM3 signal for controlling on/off of a left lower arm switch, and a PWM4 signal for controlling on/off of a right lower arm switch, the PWM1 signal and the PWM3 signal are low frequency signals and have an identical frequency and an opposite phase, the PWM2 signal and the PWM4 signal are high frequency signals. Duty ratios of PWM signals for controlling arms of a semiconductor full bridge circuit are changed according to a power consumption of the gas discharge lamp (HID) to control the power consumption of the gas discharge lamp (HID).

A control method of an electronic ballast of a gas discharge lamp (HID), to generate a PWM1 signal for controlling on/off of a left upper arm switch, a PWM2 signal for controlling on/off of a right upper arm switch, a PWM3 signal for controlling on/off of a left lower arm switch, and a PWM4 signal for controlling on/off of a right lower arm switch, the PWM1 signal and the PWM3 signal are low frequency signals and have an identical frequency and an opposite phase, the PWM2 signal and the PWM4 signal are high frequency signals. Duty ratios of PWM signals for controlling arms of a semiconductor full bridge circuit are changed according to a power consumption of the gas discharge lamp (HID) to control the power consumption of the gas discharge lamp (HID).