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US 6,570,344 B2Granted
Lamp grounding and leakage current detection system
AssigneeO2Micro International Limited
InventorYung-Lin Lin
Life of this patent
Estimating the term…
Abstract
A common ground system and methodology for one or more loads. In exemplary embodiments, a lamp load is regulated by providing a common ground on the secondary side of the transformer and the load. Lamp regulation is provided, in part, via a current feedback loop provided on the secondary side that is commonly grounded between the bottom of the transformer and the bottom of the lamp through the current feedback loop. In this manner, a feedback signal is developed that includes the leakage current of the lamp.
Claims29
An common ground circuit, comprising:
- a transformer having a primary side and a secondary side, said secondary side having a top and a bottom;
- a lamp having a top, a bottom and a leakage current path, said lamp coupled in parallel to said secondary side of said transformer, said top of said secondary side electrically coupled to said top of said lamp;
- a common ground connected to a ground node;
- and
- a current feedback loop generating a current feedback signal proportional to the total current delivered to said lamp;
- said bottom side of said transformer electrically coupled to said ground node through said current feedback loop, said bottom of said lamp electrically coupled to said ground node and said leakage current path electrically coupled to said ground node.
3 more elements
A lamp regulating circuit, comprising
- a DC to AC inverter circuit generating and an AC signal from a DC source;
- and
- a secondary-side transformer circuit, comprising:
- a transformer having a primary side and a secondary side, said secondary side having a top and a bottom;
- a lamp having a top, a bottom and a leakage current path, said lamp coupled in parallel to said secondary side of said transformer, said top of said secondary side electrically coupled to said top of said lamp;
- a common ground;
- and
- a current feedback loop generating a current feedback signal proportional to the total current delivered to said lamp;
- said bottom side of said transformer electrically coupled to said common ground through said current feedback loop, said bottom of said lamp electrically coupled to said common ground and said leakage current path electrically coupled to said common ground.
6 more elements
A transformer circuit, comprising:
- a transformer having a primary side and a secondary side, said secondary side having a top and a bottom;
- a lamp having a top, a bottom and a leakage current path, said lamp coupled in parallel to said secondary side of said transformer, said top of said secondary side electrically coupled to said top of said lamp;
- a common ground connected to a ground node;
- and
- a current feedback loop generating a current feedback signal proportional to the total current delivered to said lamp;
- said bottom side of said transformer electrically coupled to said ground node through said current feedback loop, said bottom of said lamp electrically coupled to said ground node and said leakage current path electrically coupled to said ground node;
- wherein at least a portion of energy delivered by said transformer causing said total lamp current to flow from said bottom of said transformer through said current feedback loop to said common ground, a lamp current portion of said total lamp current flows from said common ground through said lamp, and a leakage current portion of said total lamp current flows from said common ground through said leakage current path.
4 more elements
A common grounding method, comprising:
- coupling a top side of a transformer to a top side of a lamp;
- coupling a common ground to a ground node;
- and
- coupling a feedback loop circuit to a bottom side of said transformer coupled and to said ground node;
- coupling the bottom of said lamp said ground node;
- and
- coupling a leakage current path from said lamp to said ground node.
4 more elements
A transformer circuit, comprising:
- a transformer having a primary side and a secondary side, said secondary side having a top and a bottom;
- a lamp having a top, a bottom and a leakage current path, said lamp coupled in parallel to said secondary side of said transformer, said top of said secondary side electrically coupled to said top of said lamp;
- a common ground connected to a ground node;
- and
- a current feedback loop generating a current feedback signal proportional to the total current delivered to said lamp;
- said bottom side of said transformer electrically coupled to said ground node through said current feedback loop, said bottom of said lamp electrically coupled to said ground node and said leakage current path electrically coupled to said ground node;
- wherein said total current delivered to said lamp comprises a lamp current and a leakage current.
4 more elements
A transformer circuit, comprising:
- a transformer having a primary side and a secondary side, said secondary side having a top and a bottom;
- a lamp having a top, a bottom and a leakage current path, said lamp coupled in parallel to said secondary side of said transformer, said top of said secondary side electrically coupled to said top of said lamp;
- a common ground connected to a ground node;
- and
- a current feedback loop generating a current feedback signal proportional to the total current delivered to said lamp;
- said bottom side of said transformer electrically coupled to said ground node through said current feedback loop, said bottom of said lamp electrically coupled to said ground node and said leakage current path electrically coupled to said ground node;
- wherein at least a portion of energy delivered by said transformer causing said total lamp current to flow from said bottom of said transformer through said current feedback loop to said common ground, a lamp current portion of said total lamp current flows from said common ground through said lamp, and a leakage current portion of said total lamp current flows from said common ground through said leakage current path and wherein said lamp current portion and said leakage current portion summing together at the top of said lamp and totaling said total lamp current.
4 more elements
An common ground circuit, comprising:
- a transformer having a primary side and a secondary side, said secondary side having a top and a bottom;
- a lamp having a top, a bottom and a leakage current path, said lamp coupled in parallel to said secondary side of said transformer, said top of said secondary side electrically coupled to said top of said lamp;
- a common ground connected to a ground node;
- and
- a current feedback loop generating a current feedback signal proportional to the total current delivered to said lamp;
- said bottom side of said transformer electrically coupled to said ground node through said current feedback loop, said bottom of said lamp electrically coupled to said ground node and said leakage current path electrically coupled to said ground node.
- A capacitor divider in parallel with the secondary side of the transformer.
4 more elements
An LCD panel display, comprising:
- a plurality of transformers each having a primary side and a secondary side, each said secondary side having a top and a bottom;
- a plurality of lamps each having a top, a bottom and a leakage current path, each said lamp coupled in parallel to a respective said secondary side of said transformer, said top of each said secondary side electrically coupled to said top of each said lamp;
- a common ground connected to a ground node;
- and
- a plurality of current feedback loops, each said feedback loop generating a current feedback signal proportional to the total current delivered to each said lamp;
- said bottom side of each said transformer electrically coupled to said ground node through said current feedback loop, said bottom of said lamp electrically coupled to said ground node and said leakage current path electrically coupled to said ground node.
3 more elements
A computer system, comprising:
- an LCD display panel comprising,
- a transformer having a primary side and a secondary side, said secondary side having a top and a bottom;
- a lamp having a top, a bottom and a leakage current path, said lamp coupled in parallel to said secondary side of said transformer, said top of said secondary side electrically coupled to said top of said lamp;
- a common ground connected to a ground node;
- and
- a current feedback loop generating a current feedback signal proportional to the total current delivered to said lamp;
- said bottom side of said transformer electrically coupled to said ground node through said current feedback loop, said bottom of said lamp electrically coupled to said ground node and said leakage current path electrically coupled to said ground node.
4 more elements
Dependencies are inferred from the claim text.