Firing actuator power supply system
AssigneeHewlett-Packard Development Company, L.P.
InventorsJames M. Gardner, Peter J. Fricke, Mark A. Hunter
Life of this patent
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Abstract
A method and apparatus supply electrical current to a firing actuator of a printhead die across a high side switching transistor in a source follower arrangement and supply a regulated voltage, that is no greater than a concurrent voltage at a drain of the HSS transistor, to a gate of the high side switching transistor.
Claims15
An apparatus comprising:
- a first nozzle;
- a first firing actuator associated with the first nozzle;
- and
- a firing actuator power supply system comprising:
- an internal power supply path;
- a first high side switching (HSS) transistor in a source follower arrangement, the first HSS transistor having a drain electrically connected to the internal power supply path and a source electrically connected to a first end of the first firing actuator;
- and
- a voltage regulator having an input electrically connected to the internal power supply path and an output electrically connected to a gate of the first HSS transistor, the voltage regulator to provide the gate of the first HSS transistor with a controlled voltage no greater than a concurrent voltage at the drain.
The apparatus of claim l further comprising a clamp circuit having input electrically to the gate and a source of the first transistor, the clamp circuit to limit a voltage difference between the gate and the source of the first transistor.
A method comprising:
- supplying electrical current to a firing actuator of a printhead die across a high side switching transistor in a source follower arrangement;
- and
- supplying a regulated voltage, that is no greater than a concurrent voltage at a drain of the HSS transistor, to a gate of the high side switching transistor.
A power supply system for a liquid firing actuator, the power supply system comprising:
- an internal power supply path;
- a high side switching (HSS) transistor in a source follower arrangement, the HSS transistor comprising a power field effect transistor having a drain electrically connected to the internal power supply path and a source to be electrically connected to an end of the liquid firing actuator;
- and
- a voltage regulator having an input electrically connected to the internal power supply path and an output electrically connected to a gate of the HSS transistor, the voltage regulator to produce an output voltage less than a minimum system supply voltage under maximum load.
Dependencies are inferred from the claim text.