AC driver having three power supply voltages including an internally generated voltage
AssigneesCitizen Watch Co., Ltd., New Japan Radio Co., Ltd.
InventorsTomio Okigami, Shozo Ochiai
Life of this patent
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Abstract
The present invention relates to an improvement in an EL driver including a second power supply voltage producer for producing second supply voltage for use in driving an EL lamp using a battery serving as a first power source, a third supply voltage producer for producing third supply voltage that is higher than the first supply voltage and lower than the second supply voltage, and a driving signal supplier for supplying an AC driving signal to an EL driving means when driven by the third supply voltage. The level of the AC driving signal is increased in two steps. The EL driver semiconductor device characteristic of the high-voltage efficiency and high threshold voltage can therefore be driven by low voltage.
Claims20
An AC driver for driving an AC-driven member by a predetermined high voltage comprising:
- a first power source having a first output at a first voltage level;
- a second power source connected to receive the first output of the first power source and having a second output at a second voltage level that is higher than the first voltage level;
- a third power source connected to receive the first output of the first power source and having a third output at a third voltage level that is higher than the first voltage level but lower than the second voltage level;
- driving signal supplying means connected to receive and be driven by the third output and to output a predetermined AC driving signal;
- and
- driving means, connected to receive the second output and the predetermined AC driving signal, for driving said AC-driven member at the predetermined high voltage.
An AC driver for driving an AC-driven member by a predetermined high voltage comprising:
- a first power source having a first output at a first voltage level;
- a second power source for generating a second voltage level which is higher than said first voltage level and having a second output on which the second voltage level is provided;
- a third power source for generating a third voltage level at an intermediate voltage level between the first voltage level and the second voltage level, and having a third output on which the third voltage level is provided;
- driving signal supplying means powered by said third power source for outputting a first AC driving signal having an amplitude at substantially said third voltage level;
- and
- driving means powered by said second power source and supplied with said first AC driving signal for outputting a second AC driving signal having an amplitude at substantially said second voltage level for driving said AC-driven member.
Dependencies are inferred from the claim text.