Discharge Lamp Lighting Device, and Lighting Equipment and Lighting System Using the Device
First Claim
1. A discharge lamp lighting device comprising:
- a DC power source circuit;
a smoothing capacitor connected to an output end of the DC power source circuit;
an inverter main circuit adapted to convert a DC power output from the smoothing capacitor, to an AC power, and supply the AC power to a discharge lamp;
a main control circuit adapted to control the inverter main circuit so as to control the AC power to be supplied to the discharge lamp;
a timer circuit adapted to count a predetermined time;
a power supply suppression section adapted to suppress power supply to the smoothing capacitor during a period where the timer circuit counts the predetermined time;
a voltage/voltage drop detection section adapted to detect a voltage or a voltage drop of the smoothing capacitor at least during a period where the power supply to the smoothing capacitor is suppressed;
a first comparator adapted to compare between a detection value of the voltage or the voltage drop of the smoothing capacitor and a first threshold value, and output a result of the comparison; and
an auxiliary control circuit adapted to perform a control operation depending on the output of the first comparator.
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Accused Products
Abstract
A level shift IC (3b) of a power supply/shutoff section (3) is operable, when a shutoff signal (Sa) is input from a timer circuit (8) for a time T during an ON state of a discharge lamp (7), to turn off a MOSFET (3a) so as to shut off power supply to a smoothing capacitor (4). When a detection signal (Sb) of a capacitor voltage is lowered to a value less than a reference voltage Vr1 during input of the shutoff signal (Sa), an output of a comparator (10) is changed from an H level to an L level in an inverted manner. In conjunction with this change, respective outputs of an auxiliary control circuit (12) and a NOT element (12a, 12b) are changed from an L level to an H level in an inverted manner. As a result, a current flows from the NOT element (12a) to an LED (13b) through a resistor (13a) to turn on the LED (13b). Thus, a life end of the smoothing capacitor 4 is annunciated, and a main control circuit (6) is operable to suppress an output of an inverter main circuit (5).
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Citations
13 Claims
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1. A discharge lamp lighting device comprising:
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a DC power source circuit;
a smoothing capacitor connected to an output end of the DC power source circuit;
an inverter main circuit adapted to convert a DC power output from the smoothing capacitor, to an AC power, and supply the AC power to a discharge lamp;
a main control circuit adapted to control the inverter main circuit so as to control the AC power to be supplied to the discharge lamp;
a timer circuit adapted to count a predetermined time;
a power supply suppression section adapted to suppress power supply to the smoothing capacitor during a period where the timer circuit counts the predetermined time;
a voltage/voltage drop detection section adapted to detect a voltage or a voltage drop of the smoothing capacitor at least during a period where the power supply to the smoothing capacitor is suppressed;
a first comparator adapted to compare between a detection value of the voltage or the voltage drop of the smoothing capacitor and a first threshold value, and output a result of the comparison; and
an auxiliary control circuit adapted to perform a control operation depending on the output of the first comparator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification