Abstract: There is described a snubber circuit comprising an electronic switch. The circuit includes an impedance network comprising reactive circuit elements to smooth energy transients if the electronic switch is turned off and if the switch is turned on. A resistive element dissipates energy released by at least one of the reactive circuit elements. The resistive element is of a load to be driven using the electronic switch. A power supply unit may include the described snubber circuit.

Abstract: Method and devices for dynamically preventing printing errors caused by a media deformation are disclosed. In one example, a pen to print media space (PPS) distance is measured. A media deformation is identified in response to measuring the PPS distance. A corrective function is identified in response to identifying the media deformation. The corrective function identified is then performed. The proposed method provides for consistent quality across a print.

Abstract: Method and devices for dynamically preventing printing errors caused by a media deformation are disclosed. In one example, a pen to print media space (PPS) distance is measured. A media deformation is identified in response to measuring the PPS distance. A corrective function is identified in response to identifying the media deformation. The corrective function identified is then performed. The proposed method provides for consistent quality across a print.

Abstract: Examples are provided to methods to dynamically control the timing of a printing fluid drop ejection to deposit printing fluid on a print zone of a substrate. The examples may also provide measuring a height profile of a pre-print zone.

Abstract: According to one example there is provided a build material measurement module to determine build material characteristics from a build material to be analyzed.

Abstract: A method of fabricating a three dimensional object is provided. A build layer comprising an area of solidified build material and an area of non-solidified build material is formed. The build layer is formed by depositing a layer of non-solidified build material and treating the build material to form the area of solidified build material. The method also involves determining an edge profile for the build layer. Determining the edge profile involves measuring a variation in height of the build layer across a transition between the area of solidified build material and the area of non-solidified build material.

Abstract: Examples are provided to methods to dynamically control the timing of a printing fluid drop ejection to deposit printing fluid on a print zone of a substrate. The examples may also provide measuring a height profile of a pre-print zone.

Abstract: A method of aligning an agent distributor in an apparatus for generating a three-dimensional object comprises selectively depositing an agent on a layer of build material to form a predetermined alignment pattern (211, 212, 311, 312), and detecting the alignment pattern (211, 212, 311, 312) from a height profile in a surface of the build material, and performing an alignment operation using the detected alignment pattern (211, 212, 311, 312). An alignment pattern (211, 212, 311, 312) may comprise, for example, a series of triangles which are scanned to determine misalignment.

Abstract: In one example, a vapor control heater for a printer includes a housing, a heating element at least partially enclosed by the housing, and a fan to move air over the heating element and into a flow of air from the printer dryer.

Abstract: In one example, a print zone heater includes a structure defining a plenum, a heating element, a fan to move air over the heating element into the plenum, and a conduit from the plenum to carry heated air into the print zone.

Abstract: 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.

Abstract: A method is described in which a pattern is printed using a nozzle for depositing a first agent to a layer of build material, the layer of build material is cured, and the presence of a difference in height between at the edge of the first pattern is checked and an anomaly is detected if said difference is not present.

Abstract: According to one example there is provided a 3D printing system (300) comprising a build material measurement module (310) to determine a level of contraction of a solidified portion of a layer of build material. The system further comprises a controller (312) to determine if the determined level of contraction is within an acceptable range, and to modify one or multiple operating parameters of the printing system such that solidified portions of a subsequently processed layer of build material have a level of contraction within an acceptable range.

Abstract: According to one example there is provided a build material measurement module to determine build material characteristics from a build material to be analyzed.

Abstract: In one example, a heating system includes a first heater having a first resistive heating element, a second heater having multiple second resistive heating elements arranged in parallel with a group of the second heating elements having a combined resistance equal to a resistance of the first heating element, and a controller to periodically switch power between the first heating element and the group of second heating elements at a zero crossing of an AC power source.

Abstract: A method of fabricating a three dimensional object is provided. A build layer comprising an area of solidified build material and an area of non-solidified build material is formed. The build layer is formed by depositing a layer of non-solidified build material and treating the build material to form the area of solidified build material. The method also involves determining an edge profile for the build layer. Determining the edge profile involves measuring a variation in height of the build layer across a transition between the area of solidified build material and the area of non-solidified build material.

Abstract: A method of aligning an agent distributor in an apparatus for generating a three-dimensional object comprises selectively depositing an agent on a layer of build material to form a predetermined alignment pattern (211, 212, 311, 312), and detecting the alignment pattern (211, 212, 311, 312) from a height profile in a surface of the build material, and performing an alignment operation using the detected alignment pattern (211, 212, 311, 312). An alignment pattern (211, 212, 311, 312) may comprise, for example, a series of triangles which are scanned to determine misalignment.

Abstract: In one example, a heating system includes a first heater having a first resistive heating element, a second heater having multiple second resistive heating elements arranged in parallel with a group of the second heating elements having a combined resistance equal to a resistance of the first heating element, and a controller to periodically switch power between the first heating element and the group of second heating elements at a zero crossing of an AC power source.

Abstract: In one example, a print zone heater includes a structure defining a plenum, a heating element, a fan to move air over the heating element into the plenum, and a conduit from the plenum to carry heated air into the print zone.

Abstract: 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.