Patent attributes
An air compressor includes a tank unit storing a compressed air used by a pneumatic tool, a compressed air generator which generates the compressed air and supplies the compressed air to the tank unit, a motor driving the compressed air generator, a drive portion including the motor, a controller portion controlling the drive portion and a pressure sensor detecting an air pressure of the compressed air in the tank unit, in which the controller portion controls a rotation speed of the motor at multiple levels based on a detection signal P1 of the pressure sensor, a first differential signal which is a differential value d(P1)/dt of the detection signal P1, and a second differential signal which is a differential value d(P2)/dt of a detection signal P2 obtained by removing a pulsatory element from the detection signal P1.
