Methods and apparatus to control power in a printer

A circuit to control power in a printer, the circuit comprising:

• a first field effect transistor having a first terminal, a second terminal, and a third terminal, the second terminal coupled with a first voltage input;
• a second field effect transistor having a fourth terminal, a fifth terminal, and a sixth terminal, the fourth terminal coupled with the first terminal of the first field effect transistor, the fifth terminal coupled with a second voltage input;
• a first comparator having a first input coupled to the first input voltage, the first comparator having a second input coupled to the second input voltage, and the first comparator having a first output coupled with the third terminal;
• the first field effect transistor is an n-type field effect transistor;
• the first terminal is a gate terminal;
• the second terminal is a source terminal;
• the third terminal is a drain terminal;
• the second field effect transistor is an n-type field effect transistor;
• the fourth terminal is a gate terminal;
• the fifth terminal is a source terminal;
• and
• the sixth terminal is a drain terminal.

A circuit to control power in a printer, the circuit comprising:

• a first field effect transistor having a first terminal, a second terminal, and a third terminal, the second terminal coupled with a first voltage input;
• a second field effect transistor having a fourth terminal, a fifth terminal, and a sixth terminal, the fourth terminal coupled with the first terminal of the first field effect transistor, the fifth terminal coupled with a second voltage input;
• a first comparator having a first input coupled to the first input voltage, the first comparator having a second input coupled to the second input voltage, and the first comparator having a first output coupled with the third terminal;
• the first field effect transistor is a p-type field effect transistor;
• the first terminal is a gate terminal;
• the second terminal is a source terminal;
• the third terminal is a drain terminal;
• the second field effect transistor is a p-type field effect transistor;
• the fourth terminal is a gate terminal;
• the fifth terminal is a source terminal;
• and
• the sixth terminal is a drain terminal.

A circuit to control power in a printer, the circuit comprising:

• a first field effect transistor having a first terminal, a second terminal, and a third terminal, the second terminal coupled with a first voltage input;
• a second field effect transistor having a fourth terminal, a fifth terminal, and a sixth terminal, the fourth terminal coupled with the first terminal of the first field effect transistor, the fifth terminal coupled with a second voltage input, the first field effect transistor and the second field effect transistor being arranged in a wired-OR configuration;
• and
• a first comparator having a first input coupled to the first input voltage, the first comparator having a second input coupled to the second input voltage, and the first comparator having a first output coupled with the third terminal.

An apparatus to control power in a printer, the apparatus comprising:

• a comparator to receive a first voltage from a first power supply of a printer and a second voltage from a second power supply of the printer, the comparator to output a first control signal and a second control signal, the comparator to output the first control signal when the first voltage is greater than the second voltage and the first voltage is greater than a first reference voltage, the comparator to output the second control signal when the second voltage is greater than the first voltage and the second voltage is greater than a second reference voltage;
• a first switch to receive the first voltage and output a first output voltage to a power converter of the printer based on the first control signal, the first switch having a first intrinsic diode;
• and
• a second switch to receive the second voltage and to output a second output voltage to the converter based on the second control signal, the second switch having a second intrinsic diode, a first cathode of the first intrinsic diode being communicatively coupled with a second cathode of the second intrinsic diode and the power converter.

An apparatus to control power in a printer, the apparatus comprising:

• a comparator to receive a first voltage from a first power supply of a printer and a second voltage from a second power supply of the printer, the comparator to output a first control signal and a second control signal;
• a first switch to receive the first voltage and output a first output voltage to a power converter of the printer based on the first control signal, the first switch having a first intrinsic diode, the first intrinsic diode to prevent a current from the second power supply from being passed to the first power supply;
• and
• a second switch to receive the second voltage and to output a second output voltage to the converter based on the second control signal, the second switch having a second intrinsic diode, a first cathode of the first intrinsic diode being communicatively coupled with a second cathode of the second intrinsic diode and the power converter.

An apparatus to control power in a printer, the apparatus comprising:

• a comparator to receive a first voltage from a first power supply of a printer and a second voltage from a second power supply of the printer, the comparator to output a first control signal and a second control signal;
• a first switch to receive the first voltage and output a first output voltage to a power converter of the printer based on the first control signal, the first switch having a first intrinsic diode, the power converter of the printer to output power to a load of the printer regardless of a low power state of the printer;
• and
• a second switch to receive the second voltage and to output a second output voltage to the converter based on the second control signal, the second switch having a second intrinsic diode, a first cathode of the first intrinsic diode being communicatively coupled with a second cathode of the second intrinsic diode and the power converter.

An apparatus to control power in a printer, the apparatus comprising:

• a comparator to receive a first voltage from a first power supply of a printer and a second voltage from a second power supply of the printer, the comparator to output a first control signal and a second control signal;
• a first switch to receive the first voltage and output a first output voltage to a power converter of the printer based on the first control signal, the first switch having a first intrinsic diode, the first switch being a field effect transistor configured in a reverse conduction mode;
• and
• a second switch to receive the second voltage and to output a second output voltage to the converter based on the second control signal, the second switch having a second intrinsic diode, a first cathode of the first intrinsic diode being communicatively coupled with a second cathode of the second intrinsic diode and the power converter.

An apparatus to control power in a printer, the apparatus comprising:

• a comparator to receive a first voltage from a first power supply of a printer and a second voltage from a second power supply of the printer, the comparator to output a first control signal and a second control signal;
• a first switch to receive the first voltage and output a first output voltage to a power converter of the printer based on the first control signal, the first switch having a first intrinsic diode, the first intrinsic diode being a parasitic body diode:
• and
• a second switch to receive the second voltage and to output a second output voltage to the converter based on the second control signal, the second switch having a second intrinsic diode, a first cathode of the first intrinsic diode being communicatively coupled with a second cathode of the second intrinsic diode and the power converter.

An apparatus to control power in a printer, the apparatus comprising:

• a comparator to receive a first voltage from a first power supply of a printer and a second voltage from a second power supply of the printer, the comparator to output a first control signal and a second control signal;
• a first switch to receive the first voltage and output a first output voltage to a power converter of the printer based on the first control signal, the first switch having a first intrinsic diode;
• and
• a second switch to receive the second voltage and to output a second output voltage to the converter based on the second control signal, the second switch having a second intrinsic diode, a first cathode of the first intrinsic diode being communicatively coupled with a second cathode of the second intrinsic diode and the power converter, the first intrinsic diode and the second intrinsic diode to function as a wired-OR by providing power to the power converter of the printer until the at least one of the first control signal and the second control signal are generated.