Systems, circuits, and methods to mitigate effects of short-term power losses in medical systems are provided. An exemplary surgical system includes a fluidics subsystem, 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 includes 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, and a circuit that monitors the voltage on the power bus for powering the surgical instrument subsystem. The circuit automatically connects the power bus to the alternate power supply when the voltage drops below a reference voltage due to a power loss from the main power supply.