Abstract:
The present invention discloses a frequency-modulated dimming control system of a discharge lamp. The frequency-modulated dimming control system of a discharge lamp includes including a voltage regulator having a variable output voltage for converting an input voltage into a bus voltage, wherein a level of the bus voltage is a predetermined ratio of the input voltage, for example 10% of the input voltage, and a ballast circuit for driving the discharge lamp by detecting a variation of the bus voltage and then providing a current to the discharge lamp in response to a frequency modulation of the ballast circuit and the variation of the bus voltage so as to control a light intensity of the discharge lamp.
Abstract:
A printing press includes two opposite mounting walls formed with aligned horizontally extending openings in which two sliding seats are mounted slidably and respectively, a printing roller extending horizontally between the mounting walls and having a longitudinal axis and two opposite ends mounted rotatably and respectively to the sliding seats, a printing plate unit mounted securely on the printing roller, a first retaining assembly provided on one of the mounting walls for retaining releasably a first one of the sliding seats in a desired position in the respective opening, and a second retaining assembly provided on the other one of the mounting walls for retaining releasably a second one of the sliding seats in a desired position in the respective opening. The retaining assemblies are actuated simultaneously to cause longitudinal sliding movement of the sliding seats within the openings so as to result in movement of the longitudinal axis of the roller relative to the mounting walls in a direction parallel to the mounting walls. Actuation of the second retaining assembly without actuating the first retaining assembly causes longitudinal sliding movement of the second one of the sliding seats within the respective opening so as to vary an angle formed between the longitudinal axis of the printing roller and one of the mounting walls.
Abstract:
A multi-output electronic ballast is disclosed. The multi-output electronic ballast is used to drive a plurality of lamp assemblies and includes an AC/DC converter, a first inverter, a second inverter, an auxiliary voltage generator, and a control circuit. The AC/DC converter converts an AC input voltage to a high DC voltage. The first inverter converts the high DC input voltage to a first AC voltage selectively. The second inverter converts the high DC voltage to a second AC voltage. The auxiliary voltage generator generates an auxiliary voltage. The control circuit receives the auxiliary voltage generating circuit and outputs a control signal to the first inverter according to the switching operation of a first external switch. When the control signal is transmitted to the first inverter, the first inverter comes into operation and converts the high DC voltage to the first AC voltage.
Abstract:
Provided is a lamp ballast having a filament heating apparatus for gas discharge lamp, including a PFC converter for receiving an AC input voltage and converting the AC input voltage into a DC bus voltage; an inverter connected to an output end of the PFC converter for converting the DC bus voltage into an AC output voltage for driving gas discharge lamps; and a filament heating apparatus connected to the output end of the PFC converter. The filament heating apparatus includes an auxiliary heating circuit for converting the DC bus voltage into a heating power for pre-heating the filaments of the gas discharge lamps; and a control circuit connected to the inverter and the auxiliary heating circuit for generating an auxiliary voltage according to the heating power to activate the PFC converter. After the auxiliary heating circuit has been operating for a predetermined period of time, the auxiliary heating circuit is turned off first and then the inverter is turned on; or otherwise the inverter is turned on first and then the auxiliary heating circuit is turned off.
Abstract:
Provided is a lamp ballast having a filament heating apparatus for gas discharge lamp, including a PFC converter for receiving an AC input voltage and converting the AC input voltage into a DC bus voltage; an inverter connected to an output end of the PFC converter for converting the DC bus voltage into an AC output voltage for driving gas discharge lamps; and a filament heating apparatus connected to the output end of the PFC converter. The filament heating apparatus includes an auxiliary heating circuit for converting the DC bus voltage into a heating power for pre-heating the filaments of the gas discharge lamps; and a control circuit connected to the inverter and the auxiliary heating circuit for generating an auxiliary voltage according to the heating power to activate the PFC converter. After the auxiliary heating circuit has been operating for a predetermined period of time, the auxiliary heating circuit is turned off first and then the inverter is turned on; or otherwise the inverter is turned on first and then the auxiliary heating circuit is turned off.
Abstract:
A multi-output electronic ballast is disclosed. The multi-output electronic ballast is used to drive a plurality of lamp assemblies and includes an AC/DC converter, a first inverter, a second inverter, an auxiliary voltage generator, and a control circuit. The AC/DC converter converts an AC input voltage to a high DC voltage. The first inverter converts the high DC input voltage to a first AC voltage selectively. The second inverter converts the high DC voltage to a second AC voltage. The auxiliary voltage generator generates an auxiliary voltage. The control circuit receives the auxiliary voltage generating circuit and outputs a control signal to the first inverter according to the switching operation of a first external switch. When the control signal is transmitted to the first inverter, the first inverter comes into operation and converts the high DC voltage to the first AC voltage.
Abstract:
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.
Abstract:
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.
Abstract:
The configurations of a device diminishing the eddy current loss for a transformer having a gap are provided in the present invention. The proposed device includes a conductive case having an eddy current diminishing opening opposite to the air-gap and an insulator disposed between the eddy current diminishing opening and the transformer.
Abstract:
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.