A ratchet wrench includes a handle, a ratchet wheel rotatably mounted in a head of the handle, a direction controller pivotally mounted in the head of the handle, and a pawl connected with the direction controller and engaged with the ratchet wheel. The inlet, through which the exhaust gas jet enters the exhaust duct, is positioned at an upstream end of the exhaust duct. When detecting an abnormal decrease of the drive voltage of the sensor, a voltage controller maintains the applied voltage to the electric motor at the voltage at a predetermined time before the drive voltage abnormally decreased. The NMOS device further includes a first isolation structure consisting of a gate-insulating layer connected with a field oxide layer, which is formed on the P-epitaxial layer. Said orthopedic auxiliary aid is a compressive knitted part that comprises at least one receiving device for the additional functional element and at least one opening that is embedded in the knitted item allowing access to the receiving device, said opening does not negatively modify the compression properties of the auxiliary aid. Next, the nozzle plate is dried.