Hewlett-Packard Development Company, L.p.

Hewlett-Packard Company

Peter C Nicholson

David E Smith

Robert M Yraceburu

Kenneth B Wade

John A Widder

A system includes a load, one or more switches, and a controller. The switches are to switch power received from a power source to power the load. The controller is to control switching of the switches to deliver the power to the load to reduce perceptible flickering of one or more lights coupled to the power source.

Perceptible flickering reduction

One example device embodiment includes at least one first component to draw a first amount of power, at least one second component, and a power controller for allocating a second amount of power to the at least one second component to maintain a sum of the first amount of power and the second amount of power substantially constant.

Power controller

A temperature control circuit regulates temperature in an ink-jet print head. The control circuit includes a thermal sensor mounted on the print head to measure its temperature and a temperature level detector to determine whether the measured print head temperature exceeds a threshold temperature. The temperature level detector outputs a first signal when the measured print head temperature exceeds the threshold temperature and a second signal when the measured print head temperature does not exceed the threshold temperature. The control circuit also has first logic circuitry to output warming pulses upon receipt of the second signal. The warming pulses have energy insufficient to deposit an ink drop from the print head. Second logic circuitry is configured to output warming pulses to non-selected nozzles of the print head and firing pulses to selected nozzles. In this manner, the print head is automatically warmed via the warming pulses so long as the print head temperature is below a prescribed level. An ink-jet print head incorporating the control circuit is also disclosed.

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Vancouver, WA, United States of America

Peter C Nicholson