| 摘要 |
<p>The assembly is for determining the direction of rotation of a tachometer. A pair of cyclic pulse trains (E1, E2) are derived which have a 90 deg. phase relationship, during rotation of the tachometer. Both pulse trains are delayed and inverted and various combinations of the resulting four pulse trains are applied to a logic circuit. The logic circuit comprises eight AND gates grouped into two lots of four (U1, 3, 5, 7) and (U2, 4, 6, 8) which each receive three of the four possible signal groups. The output of these gates is applied to OR gates (O1, 2) the yield output signals indicative of rotational direction.</p> |
