Abstract:
Disclosed are a driving system for a semiconductor light source and a semiconductor lighting device. The driving system includes a transformer, the transformer comprising a first coil (201) and a second coil (202) coupled to each other, the second coil (202) being used for receiving an input voltage; a switching means which is connected in series to the second coil (202) of the transformer and used for controlling energy-storing and energy-releasing of the second coil (202); and an outputting means which is connected in parallel to the second coil (202) of the transformer and used for supplying power to the semiconductor light source, wherein an induced signal is generated on the first coil (201) of the transformer due to a coupling effect between the first coil and the second coil (202) and is used for controlling the turn-on or turn-off of the switching means.
Abstract:
A pulse-excited mercury-free lamp system, and method of sustaining the emission of light emission from such a lamp, is provided. The system includes a light-transmissive envelope having an inner surface and a phosphor layer coated thereon. A discharge-sustaining gaseous mixture of a noble gas, at a low pressure, and a metal halide, is retained inside the light-transmissive envelope. An electrical system provides a plurality of pulses to the discharge-sustaining gaseous mixture, resulting in a discharge, which causes the lamp system to emit light. The emission of light is maintained by turning the discharge on during a pulse width of each pulse in the plurality of pulses and by turning the discharge off during a remainder of each period in the plurality of pulses. Particularly in systems where the metal halide is indium-based, this maintains an efficient emission of light without the use of mercury.
Abstract:
A universal load control module may include a power supply that operates over a wide voltage range, a microcontroller, and one or more functional control blocks. A functional control block may include a dimmer circuit for controlling a lighting load that provides reverse phase cut mode dimming, forward phase cut mode dimming, and hybrid phase cut mode dimming, as well as thermal protection. One or more universal control modules may be housed in a cabinet that include a cabinet control module. The cabinet may include additional thermal protection measures.
Abstract:
A circuit arrangement for operating a high pressure discharge lamp includes a bridge circuit with at least two switches, a control device controlling the switches. The bridge circuit is a half-bridge circuit having exactly two switches. The control device switches on and off in an alternating manner, the first switch and the second switch of the bridge circuit having a first frequency. When the first switch is switched off for controlling the other switch with a rectangular signal of a second frequency which is greater than the first frequency and a predeterminable connection duration. The circuit also includes a tension measuring device measuring an actual value of tension over the high pressure discharge lamp. A reference device provides at least one upper threshold value for the voltage via the high pressure discharge lamp. A comparison device compares the actual voltage over the high pressure discharge lamp with the threshold value.
Abstract:
A shut-down circuit configured for use with an electronic ballast coupled to a lamp in a control path includes a device for sensing the electrical energy associated with the control path, and a sensing circuit for shutting down the ballast in the event that the energy does not conform to a predetermined condition. The sensed energy may be current indicative of lamp installation or short circuit, or voltage indicative of arcing or open circuit. The device for sensing the electrical energy associated with the control path may be an isolation transformer, or alternative devices such as optical isolators may be employed. The circuitry may further include electronic componentry to disable the sensing circuit during initial energization of the lamp. In one disclosed example, the sensing circuit includes a node that should be at or near a predetermined electrical potential when the lamp is operating properly, and a switch such as a Schmitt trigger coupled to the node that turns on or off to shut down the ballast if the node is not at or near the predetermined electrical potential. In an implementation used to detect voltage fluctuations indicative of arcing, the circuitry may include a high-pass filter or differentiator and detector to detect high-frequency noise. Alternatively, a phase-locked loop may be coupled to a low-pass filter to detect high-frequency noise indicative of arcing. In another alternative implementation, a microprocessor performing a digital signal processing algorithm may determine the presence of an abnormal condition.
Abstract:
A transistor driver includes a sender module configured to generate a power input signal. A converter module includes a transformer including a first side and a second side. The first side of the transformer is configured to receive the power input signal. A rectifier is connected to the second side of the transformer. The converter module is configured to generate an output signal at an output of the rectifier. A first receiver module is connected to each of the second side of the transformer and the output of the rectifier. The first receiver module is configured to transition a first transistor between an ON state and an OFF state based on a first signal received from the second side of the transformer.
Abstract:
A cold cathode fluorescent lamp controller exhibiting a multi-function terminal and operative alternately in a strike mode and a run mode, the controller comprising: a phase locked loop arranged for synchronization of an oscillator, associated with the controller, with an external signal, the phase locked loop comprising a capacitor coupled to the multi-function terminal; and a soft start circuit arranged to limit drive current immediately after reset of the controller responsive to a signal at the multi-function terminal. In one embodiment the controller further comprises an error detection circuit arranged to output an error signal on the multi-function terminal. In one embodiment the controller further comprises a frequency sweeping circuit operative to sweep the frequency of a drive signal during the strike mode of the controller, the frequency of the drive signal being swept by the frequency sweeping circuit responsive to a signal at the multi-function terminal.
Abstract:
A DC/AC converter circuit structure for driving a plurality of cold cathode fluorescent lamps is described. A common-mode choke is used between the cold cathode fluorescent lamps. The common-mode choke balances the currents respectively flowing through the cold cathode fluorescent lamps.
Abstract:
A transistor driver includes a sender module configured to generate a power input signal. A converter module includes a transformer including a first side and a second side. The first side of the transformer is configured to receive the power input signal. A rectifier is connected to the second side of the transformer. The converter module is configured to generate an output signal at an output of the rectifier. A first receiver module is connected to each of the second side of the transformer and the output of the rectifier. The first receiver module is configured to transition a first transistor between an ON state and an OFF state based on a first signal received from the second side of the transformer.
Abstract:
A circuit arrangement for operating a high pressure discharge lamp includes a bridge circuit with at least two switches, a control device controlling the switches. The bridge circuit is a half-bridge circuit having exactly two switches. The control device switches on and off in an alternating manner, the first switch and the second switch of the bridge circuit having a first frequency. When the first switch is switched off for controlling the other switch with a rectangular signal of a second frequency which is greater than the first frequency and a predeterminable connection duration. The circuit also includes a tension measuring device measuring an actual value of tension over the high pressure discharge lamp. A reference device provides at least one upper threshold value for the voltage via the high pressure discharge lamp. A comparison device compares the actual voltage over the high pressure discharge lamp with the threshold value.