To provide an inexpensive swing actuator whose structure is simple and compact and which resistance to environment.
A swing actuator comprises a detecting head having a plurality of induction coils at prescribed positions of a static member and a rotor having a thin ferromagnetic rotary plate 8 opposed to the detecting head and externally fitted and fixed to a rotary shaft 9. The detecting head is formed by providing a primary induction coil 5 on the circumference of the static member outside the rotary plate 8 about the rotary shaft 9. A plurality of pins 4 are provided upright in parallel with the axis of the rotary shaft 9 in positions of the static member obtained by dividing the circumference inside the primary induction coil 5 at regular intervals. A first secondary induction coil 6 induced from the primary induction coil 5 and a second secondary induction coil 7 connected in series to the first secondary induction coil 6 with both polarities opposite to those of the first secondary induction coil 6 are respectively mounted on the pins 4. In the rotor, a cut-out non-inductive part is provided on the outer peripheral edge of the rotary plate 8, by which rotational displacement in the first induction coil 5 gives a sine change or cosine change to the outputs of the first secondary induction coil 6 and the second secondary induction coil 7.
SAKAMOTO KAZUYA
KASHIMOTO HARUO
MIZUTANI MASASHI
DAIMARU KAZUHIKO
KONAN ELECTRIC CO