Patent US6781326B2 successfully refreshed from Google Patents.
US6781326B2
Expired / Lapsed
US
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Ballast with lamp sensor and method therefor
Assignee: Q Technology Inc
•
Filing: 2001-12-17
•
Granted: 2004-08-24
•
Expires: 2021-12-17
Abstract
Abstract A ballast circuit is provided having an input, an output for coupling to an electric discharge lamp and an oscillation circuit for illuminating the lamp. A circuit may be included for sensing when a voltage on an input to the oscillation circuit exceeds desired levels. The ballast circuit may be shut down, limited or otherwise controlled to reduce the possibility of ballast failure.
Inventors
- 👤 Tom Stack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:02
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/282; H05B41/285; H05B41/2851; H05B41/2853; H05B41/2855
Claims Analysis
Total Claims: 50
Claim 1
Independent Claim
163 words
A ballast circuit comprising: a DC input circuit having a high voltage line and a base line; a lamp drive circuit coupled between the high voltage line and the base line; an output circuit coupled to the lamp drive circuit for producing a lamp drive current used for driving an electric discharge lamp, the output circuit includes an inverter comprising first and second field effect transistors in a push-pull configuration including a feedback device for causing the inverter to generate an oscillating lamp drive current; and a ballast protection circuit for protecting the lamp drive circuit, comprising: a detection circuit coupled between the high voltage line and the base line configured to detect when a voltage on the high voltage line exceeds a threshold, and a shutoff device coupled to the detection circuit and to the lamp drive circuit for preventing the lamp drive circuit from producing the lamp drive current when the detected voltage on the high voltage line exceeds the threshold.
Claim 2
Dependent Claim
163 words
A ballast circuit comprising: a DC input circuit having a high voltage line and a base line; a lamp drive circuit coupled between the high voltage line and the base line; an output circuit coupled to the lamp drive circuit for producing a lamp drive current used for driving an electric discharge lamp, the output circuit includes an inverter comprising first and second field effect transistors in a push-pull configuration including a feedback device for causing the inverter to generate an oscillating lamp drive current; and a ballast protection circuit for protecting the lamp drive circuit, comprising: a detection circuit coupled between the high voltage line and the base line configured to detect when a voltage on the high voltage line exceeds a threshold, and a shutoff device coupled to the detection circuit and to the lamp drive circuit for preventing the lamp drive circuit from producing the lamp drive current when the detected voltage on the high voltage line exceeds the threshold.
Claim 3
Dependent Claim
25 words
The ballast circuit of claim 1 wherein the shutoff device is one of a silicon control rectifier, a MOSFET, a bipolar transistor and an opto-isolator.
Claim 4
Dependent Claim
23 words
The ballast circuit of claim 1 wherein at least one of the ballast protection circuit and the shutoff device includes a delay circuit.
Claim 5
Dependent Claim
17 words
The ballast circuit of claim 3 wherein the delay circuit includes a capacitor coupled to a resistor.
Claim 6
Dependent Claim
30 words
The ballast circuit of claim 1 wherein the shutoff device includes a device having a controllable conduction path coupled to the gate and source of the first field effect transistor.
Claim 7
Dependent Claim
22 words
The ballast circuit of claim 5 wherein the shutoff device is one of a silicon controlled rectifier, bipolar transistor and a MOSFET.
Claim 8
Dependent Claim
39 words
The ballast circuit of claim 1 further including an inverter starter circuit for producing a starting pulse that is applied to the gate of the first transistor for causing the inverter to start producing the oscillating lamp drive current.
Claim 9
Dependent Claim
31 words
The ballast circuit of claim 1 wherein the ballast circuit further includes a full wave rectifier coupled to the DC input circuit at the high voltage line and the base line.
Claim 10
Dependent Claim
15 words
The ballast circuit of claim 1 wherein the lamp drive circuit includes an inverter circuit.
Claim 11
Dependent Claim
18 words
The ballast circuit of claim 9 wherein the inverter circuit includes transistors arranged in a push pull configuration.
Claim 12
Dependent Claim
13 words
The ballast circuit of claim 1 wherein the shut-off device includes an SCR.
Claim 13
Dependent Claim
40 words
The ballast circuit of claim 1 wherein the detection circuit is configured to detect when a voltage on the high voltage line exceeds a value equal to approximately twice the voltage on the high voltage line under normal operating conditions.
Claim 14
Dependent Claim
20 words
The ballast circuit of claim 1 wherein the detection circuit is configured to detect a voltage greater than 200 volts.
Claim 15
Dependent Claim
20 words
The ballast circuit of claim 1 wherein the detection circuit is configured to detect a voltage greater than 212 volts.
Claim 16
Dependent Claim
30 words
The ballast circuit of claim 1 wherein the shut-off device includes a component selected from a group of a silicon control rectifier, a bi-polar transistor, an opto-isolator and a MOSFET.
Claim 17
Independent Claim
101 words
A method of protecting a ballast circuit having an inverter included in an output circuit from generating a lamp drive current that is excessive, comprising: sensing an input voltage that varies as a function of an input to the ballast; and preventing the inverter from generating a lamp drive current if the sensed voltage exceeds a predetermined voltage by preventing a transistor in the inverter from conducting current wherein the output circuit includes the inverter comprising first and second field effect transistors in a push-pull configuration including a feedback device for causing the inverter to generate an oscillating lamp drive current.
Claim 18
Independent Claim
101 words
A method of protecting a ballast circuit having an inverter included in an output circuit from generating a lamp drive current that is excessive, comprising: sensing an input voltage that varies as a function of an input to the ballast; and preventing the inverter from generating a lamp drive current if the sensed voltage exceeds a predetermined voltage by preventing a transistor in the inverter from conducting current wherein the output circuit includes the inverter comprising first and second field effect transistors in a push-pull configuration including a feedback device for causing the inverter to generate an oscillating lamp drive current.
Claim 19
Dependent Claim
40 words
The method of claim 16 further including a step of delaying the step of preventing for a predetermined time so that the starting of an electric discharge lamp does not prevent the ballast circuit from generating the lamp drive current.
Claim 20
Dependent Claim
44 words
The method of claim 16 wherein the step of preventing the inverter from generating the lamp drive current includes a step of shunting a gate voltage of the lamp drive current generating field effect transistor in order to prevent the operating of the transistor.
Claim 21
Dependent Claim
36 words
The method of claim 18 , wherein the step of shunting the gate voltage of the field effect transistor includes using one of a silicon controlled rectifier, bipolar transistor, MOSFET and opto-isolator to perform the shunting.
Claim 22
Dependent Claim
112 words
A ballast circuit comprising: an input circuit for receiving current from a current source; an inverter for producing an alternating current for a load; an output circuit for supplying power to an electric discharge lamp; and a ballast protection circuit configured between the input and the output circuits for protecting the ballast circuit from providing excessive power at the output circuit, the protection circuit including a lamp current sensing circuit for sensing a voltage in the load circuit, and a response circuit coupled to the current sensing circuit to prevent the inverter from oscillating and thus reduce the power to the output circuit when the sensed load current reaches a given level.
Claim 23
Dependent Claim
112 words
A ballast circuit comprising: an input circuit for receiving current from a current source; an inverter for producing an alternating current for a load; an output circuit for supplying power to an electric discharge lamp; and a ballast protection circuit configured between the input and the output circuits for protecting the ballast circuit from providing excessive power at the output circuit, the protection circuit including a lamp current sensing circuit for sensing a voltage in the load circuit, and a response circuit coupled to the current sensing circuit to prevent the inverter from oscillating and thus reduce the power to the output circuit when the sensed load current reaches a given level.
Claim 24
Dependent Claim
116 words
A ballast circuit comprising: an input circuit for receiving power from a power source; an output circuit for supplying drive current to an electric discharge lamp; an oscillation circuit between the input circuit and the output circuit for creating an oscillating current for the output circuit to drive the electric discharge lamp; and a ballast protection circuit coupled to the input circuit for protecting the ballast circuit from excessive drive current being developed in the output circuit, the protection circuit including at least one diode and a trigger circuit coupled to the at least one diode for reducing the drive current in the output circuit when a voltage in the input circuit reaches a given level.
Claim 25
Dependent Claim
116 words
A ballast circuit comprising: an input circuit for receiving power from a power source; an output circuit for supplying drive current to an electric discharge lamp; an oscillation circuit between the input circuit and the output circuit for creating an oscillating current for the output circuit to drive the electric discharge lamp; and a ballast protection circuit coupled to the input circuit for protecting the ballast circuit from excessive drive current being developed in the output circuit, the protection circuit including at least one diode and a trigger circuit coupled to the at least one diode for reducing the drive current in the output circuit when a voltage in the input circuit reaches a given level.
Claim 26
Dependent Claim
31 words
The ballast circuit of claim 21 wherein the oscillation circuit includes at least one transistor and wherein the trigger circuit is coupled to a gate of the at least one transistor.
Claim 27
Dependent Claim
24 words
The ballast circuit of claim 22 wherein the trigger circuit is coupled between the diode and the gate of the at least one transistor.
Claim 28
Dependent Claim
23 words
The ballast circuit of claim 23 wherein the ballast protection circuit includes at least a plurality of diodes coupled to the input circuit.
Claim 29
Dependent Claim
28 words
The ballast circuit of claim 23 wherein the trigger circuit includes a current conduction device coupled between the diode and the gate of the at least one transistor.
Claim 30
Dependent Claim
14 words
The ballast circuit of claim 25 wherein the trigger circuit includes a delay circuit.
Claim 31
Dependent Claim
14 words
The ballast circuit of claim 25 wherein the current conduction device is an SCR.
Claim 32
Dependent Claim
15 words
The ballast circuit of claim 27 wherein the oscillation circuit includes a pair of MOSFETs.
Claim 33
Dependent Claim
40 words
The ballast circuit of claim 28 wherein the SCR is coupled to a gate of one MOSFET and wherein the at least one diode is a plurality of diodes coupled between the input circuit and a gate of the SCR.
Claim 34
Dependent Claim
103 words
A ballast circuit comprising: a DC input circuit; a lamp drive circuit coupled to the DC input circuit; an output circuit coupled to the lamp drive circuit for producing the lamp drive current used for driving an electric discharge lamp; and a ballast protection circuit for protecting the lamp drive circuit, including a detection circuit coupled to the DC input circuit and configured to detect when a voltage from the DC input circuit exceeds a threshold, and a shutoff device coupled to the detection circuit and to the lamp drive circuit for preventing the lamp drive circuit from producing a lamp drive current.
Claim 35
Dependent Claim
103 words
A ballast circuit comprising: a DC input circuit; a lamp drive circuit coupled to the DC input circuit; an output circuit coupled to the lamp drive circuit for producing the lamp drive current used for driving an electric discharge lamp; and a ballast protection circuit for protecting the lamp drive circuit, including a detection circuit coupled to the DC input circuit and configured to detect when a voltage from the DC input circuit exceeds a threshold, and a shutoff device coupled to the detection circuit and to the lamp drive circuit for preventing the lamp drive circuit from producing a lamp drive current.
Claim 36
Dependent Claim
147 words
A ballast circuit comprising: a DC input circuit having a high voltage line and a base line; a lamp drive circuit coupled between the high voltage line and the base line, the lamp drive circuit includes an inverter circuit, the inverter circuit includes a pair of MOSFETs; an output circuit coupled to the lamp drive circuit for producing a lamp drive current used for driving an electric discharge lamp; and a ballast protection circuit for protecting the lamp drive circuit, comprising: a detection circuit coupled between the high voltage line and the base line configured to detect when a voltage on the high voltage line exceeds a threshold, and a shutoff device coupled to the detection circuit and to the lamp drive circuit for preventing the lamp drive circuit from producing the lamp drive current when the detected voltage on the high voltage line exceeds the threshold.
Claim 37
Dependent Claim
147 words
A ballast circuit comprising: a DC input circuit having a high voltage line and a base line; a lamp drive circuit coupled between the high voltage line and the base line, the lamp drive circuit includes an inverter circuit, the inverter circuit includes a pair of MOSFETs; an output circuit coupled to the lamp drive circuit for producing a lamp drive current used for driving an electric discharge lamp; and a ballast protection circuit for protecting the lamp drive circuit, comprising: a detection circuit coupled between the high voltage line and the base line configured to detect when a voltage on the high voltage line exceeds a threshold, and a shutoff device coupled to the detection circuit and to the lamp drive circuit for preventing the lamp drive circuit from producing the lamp drive current when the detected voltage on the high voltage line exceeds the threshold.
Claim 38
Dependent Claim
137 words
A ballast circuit comprising: a DC input circuit having a high voltage line and a base line; a lamp drive circuit coupled between the high voltage line and the base line; an output circuit coupled to the lamp drive circuit for producing a lamp drive current used for driving an electric discharge lamp; and a ballast protection circuit for protecting the lamp drive circuit, comprising: a detection circuit coupled between the high voltage line and the base line configured to detect when a voltage on the high voltage line exceeds a threshold, and a shutoff device coupled to the detection circuit and to the lamp drive circuit for preventing the lamp drive circuit from producing the lamp drive current when the detected voltage on the high voltage line exceeds the threshold, the shutoff device includes an SCR.
Claim 39
Dependent Claim
137 words
A ballast circuit comprising: a DC input circuit having a high voltage line and a base line; a lamp drive circuit coupled between the high voltage line and the base line; an output circuit coupled to the lamp drive circuit for producing a lamp drive current used for driving an electric discharge lamp; and a ballast protection circuit for protecting the lamp drive circuit, comprising: a detection circuit coupled between the high voltage line and the base line configured to detect when a voltage on the high voltage line exceeds a threshold, and a shutoff device coupled to the detection circuit and to the lamp drive circuit for preventing the lamp drive circuit from producing the lamp drive current when the detected voltage on the high voltage line exceeds the threshold, the shutoff device includes an SCR.
Claim 40
Dependent Claim
35 words
The ballast circuit of claim 32 further comprising a transistor in the lamp drive circuit having a gate and wherein the SCR is coupled to the gate of the transistor in the lamp drive circuit.
Claim 41
Dependent Claim
164 words
A ballast circuit comprising: a DC input circuit having a high voltage line and a base line; a lamp drive circuit coupled between the high voltage line and the base line; an output circuit coupled to the lamp drive circuit for producing a lamp drive current used for driving an electric discharge lamp; and a ballast protection circuit for protecting the lamp drive circuit, comprising: a detection circuit coupled between the high voltage line and the base line configured to detect when a voltage on the high voltage line exceeds a threshold, the detection circuit is configured to detect when a voltage on the high voltage line exceeds a value equal to approximately twice the voltage on the high voltage line under normal operating conditions, and a shutoff device coupled to the detection circuit and to the lamp drive circuit for preventing the lamp drive circuit from producing the lamp drive current when the detected voltage on the high voltage line exceeds the threshold.
Claim 42
Dependent Claim
164 words
A ballast circuit comprising: a DC input circuit having a high voltage line and a base line; a lamp drive circuit coupled between the high voltage line and the base line; an output circuit coupled to the lamp drive circuit for producing a lamp drive current used for driving an electric discharge lamp; and a ballast protection circuit for protecting the lamp drive circuit, comprising: a detection circuit coupled between the high voltage line and the base line configured to detect when a voltage on the high voltage line exceeds a threshold, the detection circuit is configured to detect when a voltage on the high voltage line exceeds a value equal to approximately twice the voltage on the high voltage line under normal operating conditions, and a shutoff device coupled to the detection circuit and to the lamp drive circuit for preventing the lamp drive circuit from producing the lamp drive current when the detected voltage on the high voltage line exceeds the threshold.
Claim 43
Dependent Claim
139 words
A ballast circuit comprising: a DC input circuit having a high voltage line and a base line; a lamp drive circuit coupled between the high voltage line and the base line; an output circuit coupled to the lamp drive circuit for producing a lamp drive current used for driving an electric discharge lamp; and a ballast protection circuit for protecting the lamp drive circuit, comprising: a detection circuit coupled between the high voltage line and the base line configured to detect when a voltage on the high voltage line exceeds a threshold, the detection circuit includes a series of diodes, and a shutoff device coupled to the detection circuit and to the lamp drive circuit for preventing the lamp drive circuit from producing the lamp drive current when the detected voltage on the high voltage line exceeds the threshold.
Claim 44
Dependent Claim
139 words
A ballast circuit comprising: a DC input circuit having a high voltage line and a base line; a lamp drive circuit coupled between the high voltage line and the base line; an output circuit coupled to the lamp drive circuit for producing a lamp drive current used for driving an electric discharge lamp; and a ballast protection circuit for protecting the lamp drive circuit, comprising: a detection circuit coupled between the high voltage line and the base line configured to detect when a voltage on the high voltage line exceeds a threshold, the detection circuit includes a series of diodes, and a shutoff device coupled to the detection circuit and to the lamp drive circuit for preventing the lamp drive circuit from producing the lamp drive current when the detected voltage on the high voltage line exceeds the threshold.
Claim 45
Dependent Claim
26 words
The ballast circuit of claim 35 wherein a series of diodes are coupled between the high voltage line and a gate of a current conduction device.
Claim 46
Dependent Claim
30 words
The ballast circuit of claim 36 wherein the lamp drive circuit includes at least one transistor and wherein the current conduction device is coupled to a gate of the transistor.
Claim 47
Dependent Claim
19 words
The ballast circuit of claim 36 further comprising a delay circuit coupled to the gate of current conduction device.
Claim 48
Dependent Claim
19 words
The ballast circuit of claim 36 further comprising a capacitor coupled to the gate of the current conduction device.
Claim 49
Dependent Claim
144 words
A ballast circuit comprising: a DC input circuit having a high voltage line and a base line; a lamp drive circuit coupled between the high voltage line and the base line, the lamp drive circuit includes a MOSFET; an output circuit coupled to the lamp drive circuit for producing a lamp drive current used for driving an electric discharge lamp; and a ballast protection circuit for protecting the lamp drive circuit, comprising: a detection circuit coupled between the high voltage line and the base line configured to detect when a voltage on the high voltage line exceeds a threshold, and a shutoff device coupled to the detection circuit and to a gate of the MOSFET of the lamp drive circuit for preventing the lamp drive circuit from producing the lamp drive current when the detected voltage on the high voltage line exceeds the threshold.
Claim 50
Dependent Claim
144 words
A ballast circuit comprising: a DC input circuit having a high voltage line and a base line; a lamp drive circuit coupled between the high voltage line and the base line, the lamp drive circuit includes a MOSFET; an output circuit coupled to the lamp drive circuit for producing a lamp drive current used for driving an electric discharge lamp; and a ballast protection circuit for protecting the lamp drive circuit, comprising: a detection circuit coupled between the high voltage line and the base line configured to detect when a voltage on the high voltage line exceeds a threshold, and a shutoff device coupled to the detection circuit and to a gate of the MOSFET of the lamp drive circuit for preventing the lamp drive circuit from producing the lamp drive current when the detected voltage on the high voltage line exceeds the threshold.
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