An apparatus includes a body, a motorized end effector, and a control system. The end effector extends distally from the body and comprises a stapling assembly operable to drive staples into tissue. The control system is in communication with the end effector. The control system comprises a motor, a firing trigger, a switch assembly, and a movable member in communication with the firing trigger. A resilient member is engaged with the movable member. The firing trigger and the resilient member are configured to cooperate to move the movable member into engagement with the switch to thereby activate the motor. The switch assembly is configured to couple a power source with the motor to thereby activate the motor in response to actuation of the firing trigger.
