YALOVEGY FREQUENCY TACHOMETER Russian patent published in 2005 - IPC

FIELD: measurement technology.

SUBSTANCE: tachometer can be used for measuring frequency of rotation of shafts of different power engines, namely, it has to induction tachometer. Frequency tachometer has electro-motive force excitation source made in form of C-shaped permanent magnet. Cross-section area of poles of the magnet is smaller than cross-section area of its medium part. Poles of magnetic circuit which closes magnetic flux are disposed in opposition to poles of magnet. Non-ferrous flat conducting disc is disposed between poles of magnet in perpendicular to magnetic flux. Teeth of the disc overlap at least one pole of magnet. Area of tooth of the disc is 15% bigger than area of poles of magnet. Air gap between poles of magnet and magnetic circuit doesn't exceed minimal value of linear size of pole of magnet. Poles of magnetic circuit have additional windings. The magnetic circuit is made in form of cap which is provided with support outer edge surfaces for fixing tachometer to object of measurement.

EFFECT: reduced weight and size of tachometer; higher reliability; high noise immunity.

3 cl, 4 dwg