Abstract: Disclosed herein is an electric motor control circuit, a printing device, and a method of overvoltage protection for an electric motor. The electric motor control circuit comprises a controller, a voltage converter to generate a supply voltage of the controller from a voltage at terminals of the electric motor and a switchable braking circuit connected to the motor terminals. The controller is to activate the braking circuit if the voltage at the motor terminals exceeds a threshold voltage while the controller is in an off-state.

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: A drying assembly is disclosed. An example apparatus includes fans; a temperature sensor; a print engine to access instructions to cause a printer to perform a printing operation on media; and a processor responsive to an output of the temperature sensor to control the fans to force air onto the media to cause a substantially uniform temperature to be maintained across a width of the media during the printing operation and to cause a sum of air flow output by the fans to be maintained at a substantially constant value.

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 drying assembly is disclosed. An example apparatus includes fans; a temperature sensor; a print engine to access instructions to cause a printer to perform a printing operation on media; and a processor responsive to an output of the temperature sensor to control the fans to force air onto the media to cause a substantially uniform temperature to be maintained across a width of the media during the printing operation and to cause a sum of air flow output by the fans to be maintained at a substantially constant value.

Abstract: A drying assembly is disclosed. An example apparatus includes fans; a temperature sensor; a print engine to access instructions to cause a printer to perform a printing operation on media; and a processor responsive to an output of the temperature sensor to control the fans to force air onto the media to cause a substantially uniform temperature to be maintained across a width of the media during the printing operation and to cause a sum of air flow output by the fans to be maintained at a substantially constant value.

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 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: Methods for curing ink printed on a print medium are disclosed. The methods comprise heating air to a temperature suitable for curing the ink, and blowing the air through a plurality of holes onto the print medium.

Abstract: A drying assembly is disclosed. An example apparatus includes fans; a temperature sensor; a print engine to access instructions to cause a printer to perform a printing operation on media; and a processor responsive to an output of the temperature sensor to control the fans to force air onto the media to cause a substantially uniform temperature to be maintained across a width of the media during the printing operation and to cause a sum of air flow output by the fans to be maintained at a substantially constant value.

Abstract: A drying assembly is disclosed. The drying assembly has at least 2 fan units where each fan unit has a fan. The fan speed of each fan is adjusted independently to control the air temperature from the fan. The airflow through all of the fans is maintained at a constant value.

Abstract: A drying assembly is disclosed. The drying assembly has at least 2 fan units where each fan unit has a fan. The fan speed of each fan is adjusted independently to control the air temperature from the fan. The airflow through all of the fans is maintained at a constant value.

Abstract: Methods for curing ink printed on a print medium are disclosed. The methods comprise heating air to a temperature suitable for curing the ink, and blowing the air through a plurality of holes onto the print medium.

Abstract: Methods for curing ink printed on a print medium are disclosed. The methods comprise heating air to a temperature suitable for curing the ink, and blowing the air through a plurality of holes onto the print medium.

Abstract: Examples are provided of controlling sheet media dryers. A controller operates a fan at plural duty cycles and correlates a resulting air pressure to each to define empirical data pairs. A parabolic curve fit to the empirical data is used to derive additional data pairs, and a lookup table is defined using the empirical and derived data pairs. The controller uses the lookup table to operate the fan during normal operations of a sheet media dryer.

Abstract: Examples are provided of controlling sheet media dryers. A controller operates a fan at plural duty cycles and correlates a resulting air pressure to each to define empirical data pairs. A parabolic curve fit to the empirical data is used to derive additional data pairs, and a lookup table is defined using the empirical and derived data pairs. The controller uses the lookup table to operate the fan during normal operations of a sheet media dryer.

Abstract: A system having a low power operation mode and a normal operation mode, the system including a power supply unit for supplying at least a first voltage and a second voltage; a first circuit which operates during the normal operation mode but does not operate during the low power operation mode; a second circuit which operates during the low power operation mode; and a switching unit for selectively supplying the first circuit with the first voltage or the second voltage from the power supply unit; wherein the power supply unit supplies a power status signal and the switching unit is controlled based on the power status signal.

Abstract: Methods for curing ink printed on a print medium are disclosed. The methods comprise heating air to a temperature suitable for curing the ink, and blowing the air through a plurality of holes onto the print medium.

Abstract: In one example, a media sensing system for a printer includes: a light source; a light sensor for receiving light from the light source; and a portable filter removably supported between the light source and the light sensor. The filter is configured to reduce the amount of light received by the light sensor from the light source. In another example, a method for aligning a media sensing system includes: a light source emitting light toward a light sensor; filtering the emitted light before it reaches the light sensor; the sensor sensing filtered light; and, if a desired amount of filtered light is not sensed by the sensor, then adjusting the position of the light source and/or the light sensor until the desired amount of filtered light is sensed by the sensor.