Surgical systems including a power loss mitigation subsystem

A surgical system comprising:

• a surgical instrument subsystem that couples to a surgical instrument;
• and
• a power supply subsystem coupled to the surgical instrument subsystem, the power supply subsystem comprising:
• a main power supply connectable to AC mains to generate a voltage;
• a power bus connected to the main power supply;
• an alternate power supply comprising at least two capacitors, wherein the at least two capacitors comprise a first capacitor for tracking a voltage on the power bus and a second capacitor to provide stand-by voltage to the power bus when connected to the power bus;
• and
• a circuit that monitors the voltage on the power bus for powering the surgical instrument subsystem and automatically connects the power bus to the second capacitor of the alternate power supply when the voltage drops below a reference voltage due to a power loss from the main power supply;
• wherein the second capacitor provides the stand-by voltage to the power bus when connected to the power bus such that the power bus can maintain the voltage while the second capacitor is charged;
• wherein the circuit automatically connects the power bus back to receiving power from the main power supply when the power loss is discontinued;
• and
• wherein the second capacitor is recharged while the power bus is receiving power from the main power supply.