Electronic ballast for instant-start lamps
First Claim
1. An arrangement comprising:
- a source operative to provide a DC supply voltage;
circuit assembly connected with the DC supply voltage and operative to provide a squarewave output voltage at a pair of output terminals;
the circuit assembly having a first control input and being operative, on receipt of a first control signal at the first control input, to control the peak magnitude of the squarewave output voltage;
the circuit assembly being further characterized by including an inverter circuit and a control circuit in interconnected combination;
the circuit assembly being further characterized by not including a relay with a relay coil; and
gas discharge lamp disconnectably connected in circuit with the output terminals.
3 Assignments
0 Petitions
Accused Products
Abstract
In an electronic ballast, a full-bridge inverter is powered from a DC voltage and provides a square-wave-like inverter output voltage. This inverter output voltage, which has a peak amplitude equal to the magnitude of the DC voltage, is applied to an instant-start fluorescent lamp via a current-limiting inductor connected in series with a DC blocking capacitor. The DC voltage is obtained by way of a pre-converter with a control input operative to permit control of the magnitude of the DC voltage. Prior to the flow of lamp current, the magnitude of the DC voltage is controlled by negative feedback to the control input so as to remain at a certain maximum level. About 100 milli-seconds after initial flow of lamp current, one half of the full-bridge inverter is disabled, thereby reducing the amplitude of the inverter output voltage by half. Additionally, by negative feedback derived from the lamp current itself, the magnitude of the DC voltage is reduced so as to bring the magnitude of the lamp current down to a pre-established desired level.
84 Citations
28 Claims
-
1. An arrangement comprising:
-
a source operative to provide a DC supply voltage; circuit assembly connected with the DC supply voltage and operative to provide a squarewave output voltage at a pair of output terminals;
the circuit assembly having a first control input and being operative, on receipt of a first control signal at the first control input, to control the peak magnitude of the squarewave output voltage;
the circuit assembly being further characterized by including an inverter circuit and a control circuit in interconnected combination;
the circuit assembly being further characterized by not including a relay with a relay coil; andgas discharge lamp disconnectably connected in circuit with the output terminals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. An arrangement comprising:
-
a power line source operative to provide an ordinary electric utility power line voltage at a pair of power line terminals; a power conditioning circuit connected with the power line terminals and operative to provide a DC supply voltage at a pair of DC terminals;
the magnitude of the DC supply voltage starting to increase at a first point in time, thereby to reach a first pre-determined magnitude after a first brief duration;
the first brief duration being longer than a complete cycle of the power line voltage;an inverter circuit connected with the DC terminals and operative, but only after the magnitude of the DC supply voltage has reached said first pre-determined magnitude, to provide an AC output voltage at a pair of inverter output terminals; a gas discharge lamp having lamp terminals; and sub-structure operable to provide connection between the lamp terminals and the inverter output terminals; the arrangement being further characterized by not including a relay with a relay coil. - View Dependent Claims (11, 12, 13)
-
-
14. An arrangement comprising:
-
a power line source operative to provide an ordinary electric utility power line voltage at a pair of power line terminals;
the power line voltage having a fundamental period;a power conditioning circuit connected with the power line terminals and operative to provide a DC supply voltage at a pair of DC terminals;
the power conditioning circuit being characterized by including an intermittently conducting transistor and an energy-storing inductor;
the magnitude of the DC voltage starting to increase at a first point in time and reaching a first pre-determined magnitude after a first brief duration;
the first brief duration being longer than half the duration of said fundamental period;an inverter circuit connected with the DC terminals and operative, but only after the magnitude of the DC supply voltage has reached said first pre-determined magnitude, to provide an AC output voltage at a pair of inverter output terminals; a gas discharge lamp having lamp terminals; and sub-structure operable to provide connection between the lamp terminals and the inverter output terminals; the arrangement being further characterized by not including a relay with a relay coil.
-
-
15. An arrangement comprising:
-
a series-combination of a gas discharge lamp and a predominantly inductive current-limiting means;
the series-combination having a pair of input terminals; anda voltage source having a pair of output terminals connected with the input terminals of the series-combination;
the voltage source being characterized by;
(i) at a given point in time, providing at the output terminals an AC voltage having a first pre-determined magnitude; and
(ii) at a subsequent pre-determined point in time, causing the magnitude of the AC voltage to decrease to a second pre-determined magnitude;the arrangement being further characterized by not including a relay with a relay coil. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
-
-
23. An arrangement comprising:
-
a power line source operative to provide an ordinary electric utility power line voltage between a first and a second power line terminal; a power conditioning circuit connected with the power line terminals and operative to provide a DC supply voltage between a first and a second DC terminal;
there being an electrically conductive path between the first DC terminal and the first power line terminal;an inverter circuit connected with the DC terminals and operative to provide an AC output voltage between a first and a second AC output terminal;
a first AC voltage existing between the first DC terminal and the first AC output terminal;
a second AC voltage existing between the first DC terminal and the second AC terminal;
the magnitude of the first AC voltage being at least one quarter the magnitude of the second AC voltage;
the phasing of the first AC voltage being opposite that of the second AC voltage;a gas discharge lamp having lamp terminals; and sub-structure operable to provide connection between the lamp terminals and the inverter output terminals; the arrangement being further characterized by not including a relay and a relay coil. - View Dependent Claims (24, 25, 26, 27, 28)
-
Specification