摘要:
A ballast comprising a first input terminal, a second input terminal, a switch circuit, and a plurality of lamp sets is provided. The switch circuit comprises a first switch and a second switch connected with the first one. The switches are connected with the first and second input terminals respectively. The lamp sets are connected in parallel with each other and have an arrangement sequence. Each of the lamp sets is coupled to the first and second switches and comprises a first lamp having a first filament. The filaments are connected in series according to the arrangement order so that at least one junction is formed in the at least one connection point. The first one of the first filaments is coupled to the first switch. The last one of the first filaments is coupled to the second switch. Thereby, the ballast can be implemented by less internal connection terminals and leads.
摘要:
A current-preheat electronic ballast includes an AC-to-DC converter, a controlling unit, an auxiliary voltage generator, and an inverter. The inverter is connected with the DC bus for converting a high DC voltage into an AC output voltage and generating a resonant current and a lamp filament current to a lamp group. The inverter includes a resonant circuit and a resonant capacitor adjusting circuit. The resonant circuit provides electric energy required to preheat the lamp group. The resonant capacitor adjusting circuit judges whether the inverter is enabled according to the detecting element. After the inverter has been enabled for a delayed time, two high-voltage switching terminals of the resonant capacitor adjusting circuit are correspondingly conducted or shut off, so that an equivalent resonant capacitance value of the resonant circuit is changed and a voltage drop across two ends of a lamp filament of the lamp group is changed.
摘要:
The configurations of a two way wiring device are provided in the present invention. The proposed device includes a case having a first side, a second side opposite to the first side, a third side formed between the first side and the second side and an open bottom passing therethrough a first conducting wire, wherein the third side includes a first side segment, a second side segment and a middle segment located between the first and the second side segments, and a conducting wire guiding pathway formed on the case and the first conducting wire passing the pathway and wired out of the case through one of the first side segment and the second side segment.
摘要:
The present invention provides an illumination device, an illumination system, and a lamp. The illumination system includes the illumination device and a light modulation module. The illumination device includes a light emitting diode (LED) array, an alternating current (AC) current source, and an output power control module. The AC current source is electrically coupled to the LED array. The output power control module is electrically coupled to the LED array and the AC current source. The LED array, the AC current source, and the output power control module together form a closed-loop control loop. The light modulation module is electrically coupled to the closed-loop control loop for modulating illumination brightness of the LED.
摘要:
An electronic ballast for a light emitting load is provided, and includes a transformer module, a resonance module, a high-frequency push-pull inverter and a driving controller module. The high-frequency push-pull inverter includes a first switch component and a second switch component. The driving controller module is used for generating and providing an asymmetric driving waveform to the first switch component and the second switch component. The asymmetric driving waveform includes a first discharging waveform portion for discharging and turning off the first switch component, and also a second discharging waveform portion for discharging and turning off the second switch component. The first and second discharging waveform portions are different in current amplitudes and time spans.
摘要:
The present invention relates to a method adopting square voltage waveform for driving a flat lamp used as the light source of a flat panel display or a common light fixture, the method comprising steps of: using a power unit to convert direct current into voltage of square waveform; using a voltage booster to raise the crest of the square voltage waveform to a specific trigger voltage capable of turning on the flat lamp; and providing a pulse-type current while enabling the pulse-type current to be just larger enough to break the dielectric barrier of the flat lamp.
摘要:
A lighting device is provided, having at least one light emitting diode module, a power factor correction circuit, a non-regulated isolation DC to DC converter and at least one regulated non-isolation DC to DC converter. The power factor correction circuit performs a power factor correction on an AC power source and outputs a corrected DC voltage. The non-regulated isolation DC to DC converter generates an output voltage in a predetermined voltage range according to the corrected DC voltage, wherein the non-regulated isolation DC to DC converter is an open-loop controlled buck DC to DC converter. The regulated non-isolation DC to DC converter generates a fixed current or a fixed voltage according to the output voltage output from the non-regulated isolation DC to DC converter, thereby driving the light emitting diode module.
摘要:
A current-preheat electronic ballast includes an AC-to-DC converter, a controlling unit, an auxiliary voltage generator, and an inverter. The inverter is connected with the DC bus for converting a high DC voltage into an AC output voltage and generating a resonant current and a lamp filament current to a lamp group. The inverter includes a resonant circuit and a resonant capacitor adjusting circuit. The resonant circuit provides electric energy required to preheat the lamp group. The resonant capacitor adjusting circuit judges whether the inverter is enabled according to the detecting element. After the inverter has been enabled for a delayed time, two high-voltage switching terminals of the resonant capacitor adjusting circuit are correspondingly conducted or shut off, so that an equivalent resonant capacitance value of the resonant circuit is changed and a voltage drop across two ends of a lamp filament of the lamp group is changed.
摘要:
The configurations of an end of lamp life protection circuit for a ballast and a method thereof are provided in the present invention. The proposed circuit includes a voltage-dividing circuit receiving an input voltage and outputting a first and a second divided voltages and a switch apparatus raising the first divided voltage when the second divided voltage is less than a first pre-determined threshold value and turning off the ballast when the first divided voltage is higher than a second pre-determined threshold value.
摘要:
An electronic ballast includes an inductor, an output transformer, at least two switching elements, a control circuit, a clamping circuit, and at least two return circuits. The inductor is electrically coupled to a DC power supply. The control circuit is electrically connected to the inductor, the output transformer and the switching elements for controlling on/off statuses of the switching elements. The clamping circuit is electrically connected to the inductor, and limits a node voltage among the inductor, the control circuit, and the clamping circuit below a threshold value and generates an output current on condition that the node voltage is larger than the threshold value. Each of the return circuits is electrically connected to the clamping circuit and coupled to both terminals of one of the switching elements for transmitting the output current to the output transformer, thereby permitting a reverse voltage of the switching elements within a maximum allowable range of the switching elements.