Lamp driving topology
AssigneeO2Micro International Limited
InventorsJohn Chou, Arnel Dela Cruz
Life of this patent
Estimating the term…
Abstract
A lamp driving system that includes a first impedance and a second impedance coupled to the secondary side of a transformer, where the second impedance has a phase shifted value compared to the first impedance. Two lamp loads are connected in series together, and in parallel to the first and second impedances and to the transformer. The phase shift between the impedances ensures that the transformer need not supply double the striking voltage to strike the series-connected lamps. A difference in the resistance between the first and second impedances ensures that the lamps ignite in a specified sequence.
Claims34
A load driving system, comprising:
- a power source;
- a first impedance network coupled in series to a second impedance network, said second impedance network having a different impedance value and phase-shifted with respect to said first impedance network, said first and second impedance networks coupled in parallel to said power source;
- and
- a first load coupled in series to a second load, said first and second load coupled in parallel to said first and second impedance networks, respectively;
- wherein said impedance difference between said first and second impedance networks generating a selected sequence of initial voltage for said first and second loads.
A lamp driving system, comprising:
- a transformer;
- a first impedance network coupled in series to a second impedance network, said first impedance network having a larger impedance value than said second impedance network, said first and second impedance networks coupled in parallel to a secondary side of said transformer;
- and
- a first lamp coupled in series to a second lamp, said first and second lamps coupled in parallel to said first and second impedance networks, respectively;
- wherein the said larger impedance value of said first compared to second impedance networks causing said first lamp to strike before said second lamp.
A circuit, comprising a first impedance network coupled in series to a second impedance network, said second impedance network having a different impedance value and phase-shifted with respect to said first impedance network, said first and second impedance networks coupled in parallel to a power source;
- and a first load coupled in series to a second load, said first and second loads coupled in parallel to said first and second impedance networks;
- wherein said impedance difference between said first and second impedance networks generating a selected sequence of initial voltage for said first and second loads.
A circuit, comprising a first impedance network coupled in series to a second impedance network, said second impedance network having a different impedance value and phase-shifted with respect to said first impedance network, said first impedance network having a larger impedance value than said second impedance network, said first and second impedance networks coupled in parallel to a power source;
- and a first lamp coupled in series to a second lamp, said first and second lamps coupled in parallel to said first and second impedance networks, respectively;
- wherein said impedance difference between said first and second impedance networks causing said first lamp to strike before said second lamp.
Dependencies are inferred from the claim text.