Powered surgical instrument with pressure sensitive motor speed control

A surgical instrument comprising:

• a drive shaft;
• at least one drive mechanism operatively connected to the drive shaft, the at least one drive mechanism being configured to selectively move a tool assembly of an end effector relative to a proximal portion of the end effector, to rotate the end effector about a longitudinal axis relative to a handle housing, or to move an anvil assembly relative to a cartridge assembly of the end effector between open and clamped positions;
• a motor for actuating the drive shaft via the drive mechanism;
• a motor speed control including a first switch and a second switch, each of the first and second switches in communication with the motor, the first switch disposed over the second switch and in registration therewith, the first switch having an activated state when a force applied to the first switch exceeds a threshold force, wherein the first switch sends a first signal to the motor such that the motor rotates the drive shaft at a constant speed, the second switch sending a second signal to the motor that varies the speed that the motor rotates the drive shaft in response to an amount of the force applied to the first switch which exceeds the threshold force;
• and
• a force resistor disposed within the second switch and configured to send a pressure signal to a first op amp, such that when the pressure signal is greater than a threshold value the first op amp activates a second op amp to send the first signal to the motor speed control configured to supply energy to the motor, while simultaneously sending a second signal that is proportional to the pressure signal to the motor speed control, such that the second signal to the motor varies the speed that the motor rotates the drive shaft in response to an amount of the force applied to the first switch which exceeds the threshold force.