DETECTING SYSTEM FOR ORIGINAL POINT OF POSITION CONTROL MACHINE

摘要

PURPOSE:To detect a rough original point with a simple constitution by replacing a detector for rough original point with a current detecting circuit of an electric motor. CONSTITUTION:When a detection command for original point is supplied to a control circuit 10 of an electric motor 1 from a central controller, the motor 1 is controlled to the minimum speed. At the same time, a mobile body 5 also starts its right movement at the minimum speed via a drive mechanism 6. Then a dock 3 set to the body 5 has a contact with a stopper 4 of a base 11 with more right movement of the body 5. Thus the load becomes infinite and a large current flows to the motor 1. The variation of said large current is detected by a detection circuit 8 for rough original point. Then the motor 1 is reversed and controlled by a control circuit 10 so that the body 5 is moved left. Then a detection circuit 7 for fine original point detects an original point pulse of an encoder 2 connected to the motor 1. Thus an end signal for detection of original point is delivered from a detection circuit 9 for original point to finish the detection of original point.