Hewlett-packard Development Company, L.p.

Fernando Bayona Alcolea

Michel Georges Encrenaz

Emilio Angulo Navarro

Albert Crespi Serrano

Mikel Zuza Irurueta

Jorge Castano Aspas

Santiago Sanz Ananos

Alfonso Cameno Salinas

Emilio Lopez Matos

Bhishma Hernandez Martinez

Pedro Miguel Teixido Rovira

Jose Ma Rio Doval

The present subject matter describes a heating unit. The heating unit comprises a heating element and a controlling unit coupled to the heating element to determine a desired value of a direct current (DC) voltage based on heating element parameters. The desired value is a value of DC voltage desired for operation of the heating element. The controlling unit computes a value of a duty cycle parameter based on device input parameters and the desired value of the DC voltage. The heating unit further comprises a power factor correction (PFC) unit coupled to the controlling unit and the heating element to convert an input alternating current (AC) voltage, received by the PFC unit from an AC supply, to a direct current (DC) voltage of the desired value based on the duty cycle parameter. The PFC unit provides the DC voltage to the heating element.

Heating unit

A pump for the transfer a predetermined total volume of fluid from a pump inlet to a pump outlet in a unit of time is calibrated by deriving a count of the number of times a volume of the fluid is transferred from a pump inlet to a pump outlet in a unit of time; and adjusting the number of times the volume is transferred in a unit of time until the derived count is substantially equal to a predetermined threshold value.

Calibration of a pump

An example in accordance with an aspect of the present disclosure includes an ink channel of a printer, coupleable to an ink supply to receive an ink. A sensor assembly is mounted to the ink channel, including a sensor in fluid communication with the ink channel to identify an ink level of the ink supply based on a pressure difference between an air pressure, associated with the sensor assembly, and an ink pressure, associated with the ink channel.

Sensor assemblies to identify ink levels

Inputting an input resistance to an operational amplifier. Detecting whether a number of fans are in operation based on the input resistance to the operational amplifier by driving a number of resistors connected in series in a fan circuit associated with the number of fans.

Fan operation detection

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Terrassa, Spain

Fernando Bayona Alcolea