A safety razor has a handle and a cartridge selectively detachable from the handle. The cartridge has at least one blade with a sharp cutting edge and an expected shaving utility. A connecting structure is coupled to the handle and attaches or detaches the cartridge from the handle in response to a detachment action performed by a user. A detector within the handle has an actuator coupled to the connecting structure and a sensor for generating a signal, wherein the actuator applies an action on the sensor during the action and the sensor generates the signal in response to the action.