Power supply and inverter used therefor
First Claim
1. A power supply for a system with a lamp, comprising:
- a rectifier/filter, having an input terminal for connecting to an external alternating current (AC) power source so as to convert the input AC voltage into a direct current (DC) voltage, and an output terminal for outputting the DC voltage;
a DC-DC converter, connected to the output terminal of said rectifier/filter for reducing the DC voltage to a rated DC voltage output to power the system except for the lamp;
a DC-AC inverter, connected to the output terminal of said rectifier/filter for converting the DC voltage into an AC voltage output to power the lamp; and
wherein said DC-AC inverter further comprises;
two switches, having a common output terminal and respectively having a control input terminal;
a driving circuit, electrically coupled to the respective control input terminals of the two switches, for alternatively turning on the two switches;
a transformer, having a primary side electrically coupled to the common output terminal of the two switches and a secondary side electrically coupled to the lamp;
a sampling circuit, electrically coupled to the lamp, for detecting the current value through the lamp and outputting a feedback signal;
a modulation control circuit, electrically coupled to the sampling circuit and the driving circuit, for controlling the driving circuit according to the feedback signal;
a voltage detection circuit with an input terminal, for outputting a control signal according to the voltage amplitude at the input terminal; and
an impedance adjustment circuit, electrically coupled to the voltage detection circuit and the transformer, for adjusting the equivalent impedance value of the impedance adjustment circuit according to the control signal.
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Accused Products
Abstract
This invention relates to a power supply that integrates a rectifier/filter'"'"'s circuitry and a converter'"'"'s circuitry with an inverter to reduce space occupied and increase power efficiency. The power supply includes: a rectifier/filter, a DC-DC converter and a DC-AC inverter. The rectifier/filter, connected to an alternating current (AC) input terminal, converts the input AC into a direct current (DC). The DC-DC converter and the DC-AC inverter are parallel to each other with one end concurrently connected to the rectifier/filter'"'"'s output and the other end respectively outputting the desired powers. As such, DC-DC converter reduces the converted DC voltage to lower DC voltages to power all circuits except for the lamp and DC-AC inverter converts the converted DC voltage into higher AC voltage output to drive the lamp.
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Citations
26 Claims
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1. A power supply for a system with a lamp, comprising:
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a rectifier/filter, having an input terminal for connecting to an external alternating current (AC) power source so as to convert the input AC voltage into a direct current (DC) voltage, and an output terminal for outputting the DC voltage;
a DC-DC converter, connected to the output terminal of said rectifier/filter for reducing the DC voltage to a rated DC voltage output to power the system except for the lamp;
a DC-AC inverter, connected to the output terminal of said rectifier/filter for converting the DC voltage into an AC voltage output to power the lamp; and
wherein said DC-AC inverter further comprises;
two switches, having a common output terminal and respectively having a control input terminal;
a driving circuit, electrically coupled to the respective control input terminals of the two switches, for alternatively turning on the two switches;
a transformer, having a primary side electrically coupled to the common output terminal of the two switches and a secondary side electrically coupled to the lamp;
a sampling circuit, electrically coupled to the lamp, for detecting the current value through the lamp and outputting a feedback signal;
a modulation control circuit, electrically coupled to the sampling circuit and the driving circuit, for controlling the driving circuit according to the feedback signal;
a voltage detection circuit with an input terminal, for outputting a control signal according to the voltage amplitude at the input terminal; and
an impedance adjustment circuit, electrically coupled to the voltage detection circuit and the transformer, for adjusting the equivalent impedance value of the impedance adjustment circuit according to the control signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An inverter for driving a discharge lamp, comprising:
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two switches having two separately respective control input terminals and a common output terminal;
a driving circuit, electrically coupled to the two control input terminals of the switches, for alternatively turning on the two switches;
a transformer, having a primary side electrically coupled to the common output terminal of the switches and a secondary side electrically coupled to the lamp;
a sampling circuit;
electrically coupled to the lamp, for detecting the current value through the lamp and outputting a feedback signal;
a modulation control circuit, electrically coupled to the sampling circuit and the driving circuit, for controlling the driving circuit according to the feedback signal;
a voltage detection circuit with an input terminal, for outputting a control signal according to the voltage amplitude of the input terminal; and
an impedance adjustment circuit, electrically coupled to the voltage detection circuit and the transformer, for adjusting the equivalent impedance value of the impedance adjustment circuit according to the control signal.- View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. An inverter, for converting an input voltage to drive a discharge lamp, comprising:
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two switch transistors, respectively having a control input terminal and having a common output terminal;
a driving circuit, electrically coupled to the respective control input terminals of the two switch transistors, for alternatively turning on the two switch transistors;
a transformer, having a primary side electrically coupled to the common output terminal of the two switch transistors and a secondary side electrically coupled to the lamp;
a sampling circuit, electrically coupled to the lamp, for detecting the current value through the lamp and outputting a feedback signal;
a modulation control circuit, electrically coupled to the sampling circuit and the driving circuit, for controlling the driving circuit according to the feedback signal to regulate the brightness of the lamp;
a voltage detection circuit having a comparator, the comparator having an input terminal electrically coupled to the input voltage of the inverter and another input terminal electrically coupled to a predetermined reference voltage so as to output a control signal according to the comparison result of the input voltage and the predetermined reference voltage; and
an impedance adjustment circuit, having one side electrically coupled to the transformer and the other side electrically coupled to the voltage detection circuit via a control input terminal of a control switch, for adjusting the equivalent impedance of the impedance adjustment circuit by controlling the on/off status of the control switch according to the control signal. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26)
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Specification