抄録
A linear motor is controlled by feedback control. The characteristic of the linear motoris determined by the characteristic of the motor itself, a position detector and a controlsystem. So the position detector is needed fine positioning and fast response.
This paper states new type position detector which is able to built in the moving magnet type (MM-type) linear DC motor (LDM). As the MM-type LDM has merit that it needs no wire fordrive to move, this position detector is developed for making the best use of this merit. This position detector uses the capacitance between the mover and electrode which is installed on the stator. The capacitance changes in proportion to the displacement of themover. It is important to convert accurately the change of capacitance depending on displacement of the mover into direct voltage. After several electric circuits are examined, as the result, the best circuit is chosen, and then the simple, non-contact, cheap and accu-rate differential type position detector is developed.
