A powered surgical instrument comprising an end effector, a sensor configured to output a signal, an elongate shaft, and a handle is disclosed. The end effector comprises a first jaw, a second jaw movable relative to the first jaw, a channel, a staple cartridge, an anvil, and a firing member configured to be driven during a firing stroke. The firing member experiences a pushing force during the firing stroke and comprises a knife portion, a first camming member configured to engage the first jaw, a second camming member configured to engage and position the second jaw. The handle comprises a motor, a battery, means for detecting the pushing force of the firing member, and a control unit configured to receive the signal from the sensor. The control unit includes a microprocessor which utilizes a pulse width modulation circuit to control the motor based on the signal received from the sensor.