Switching power supply, method of operation and device-and-power-supply assembly

1. A method for operating a switching power supply, wherein the switching power supply includes a primary side having a primary side controller and includes a secondary side inductively coupled to the primary side, wherein a power-supply-using device receives at least one voltage from the secondary side and has a device controller which controls the device, and wherein the method comprises the steps of:

a) obtaining a power-supply control signal or power-supply control data from the device controller; and

b) using at least the power-supply control signal or the power-supply control data to generate an input control signal for the primary side controller, wherein the device is an ink jet printer without a power supply, and wherein the device controller is a printer controller which controls the ink jet printer.

2. The method of claim 1 , wherein the at-least-one voltage includes a print head voltage, and wherein the power-supply control signal or the power-supply control data obtained in step a) is based at least in part on the print head voltage measured at the print head.

3. The method of claim 1 , wherein the power-supply control signal or the power-supply control data obtained in step a) is based at least in part on substantially matching the power supplied by the switching power supply with the different power needs of the ink jet printer to operate in different ones of a plurality of operating modes.

4. The method of claim 3 , wherein the operating modes are chosen from at least two of the group consisting of: a power-up mode, a shut-down mode, a low power standby mode, an operating mode of a first print head requiring a first voltage, an operating mode of a second print head requiring a different second voltage, and a paper feed operating mode.

5. The method claim 4 , also including the stop of superimposing a modulating waveform on the input control signal to reduce EMI (electromagnetic interference).

6. The method of claim 4 , also including the step of adjusting the input control signal to maintain stability of the at-least-one voltage when the operating mode is the low power standby mode.

7. The method of claim 1 , also including the step of sending a power-supply identification signal from the switching power supply to the printer controller, wherein step a) obtains a power-supply control signal from the device controller, and wherein the power-supply control signal obtained in step a) is based at least in part on the identification signal.

8. A device-and-power-supply assembly comprising:

a) a switching power supply having a primary side including a primary side controller and having a secondary side lacking a secondary side controller and inductively coupled to the primary side for producing at least one voltage;

b) a power-supply-using device receiving the at-least-one voltage from the secondary side and having a device controller which controls the device;

c) a signal path electrically coupling the device controller to the primary side controller, wherein the primary side controller is adapted to receive an input control signal generated at least in part from a power-supply control signal obtained along the signal path from the device controller; and

d) an ink jet printer housing, wherein the device is an ink jet printer without a power supply, wherein the device controller is a printer controller which controls the ink jet printer and which resides in an application specific integrated circuit (ASIC), wherein the ASIC and the switching power supply reside in the printer housing, and wherein the ASIC is electrically connected to the switching power supply by a cableless connection.

9. A switching power supply comprising a primary side and a secondary side, wherein the primary side includes a primary side controller, wherein the secondary side lacks a secondary side controller and is inductively coupled to the primary side for producing at least one voltage, wherein the secondary side is connectable to a power-supply-using device receiving the at-least-one voltage and having a device controller which controls the device, wherein the primary side controller is adapted to receive an input control signal generated at least in part from a power-supply control signal obtained from the device controller along a signal path electrically coupling the device controller to the primary side controller when the secondary side is connected to the device, wherein the switching power supply is adapted to send a power-supply identification signal to the device controller when the secondary side is connected to the device, wherein the power-supply control signal is based at least in part on the power-supply identification signal, and wherein the device is an ink jet printer without a power supply, wherein the device controller is a printer controller which controls the ink jet printer, and wherein the signal path includes an optocoupler.

10. A switching power supply comprising:

a) a primary side including a primary side controller: and

b) a secondary side including a secondary side controller, wherein the secondary side is inductively coupled to the primary side for producing at least one voltage, wherein the secondary side is connectable to a power-supply-using device receiving the at-least-one voltage and having a device controller which controls the device, wherein the secondary side controller is adapted to receive power-supply control data along a data path from the device controller when the secondary side is connected to the device, and wherein the primary side controller is adapted to receive an input control signal from the secondary side controller generated at least in part from the power-supply control data, wherein the data path is a bidirectional data, and wherein the device is an ink jet printer without a power supply, and wherein the device controller is a printer controller which controls the ink jet printer.