SYNCHRONOUS SWITCH

The invention relates to a synchronous switch meant to supply the primary winding of an electric transformer in order to study the conditions of supplying for idle and short-circuit operations. According to the invention, the switch comprises a reactive synchronous micromotor (1) on whose shaft there is fixed a disk (2), on whose surface there is fixed, on a radial direction, a permanent magnet (3) which rotate integrally with the disk (2), a second disk (4) is mounted in front of disk (2), coaxially therewith, said second disk being radially provided on one side with two magnetically actuated contacts (5 and 5') in opposing positions, and on the opposite side there is placed a scale (6) graduated with sexagesimal degrees from 0° to 360° which rotates integrally with the disk (4) modifying the position of contacts (5 and 5') relative to a reference position indicated by a mark (7) fixed in front of the graduated scale (6); the change of position of the disk (4) can be achieve by means of a rosette (8) which, together with the disk (4), is fixed on a shaft (9) mounted on a fixed support (10). Upon each rotation of the disk (2) driven by the synchronous motor (1), the magnet (3) actuates the contacts (5 and 5'), determining the closure thereof for a short period of time.