Controllable oscillator for a correlation tachometer

摘要

A numerically controlled oscillator (23) is specified for a digitally operating correlation tachometer. The latter has a basic oscillator (30) whose frequency f is reduced by a binary divider (32). Controlled by a value E, a drive logic (36) respectively connects one of the outputs of the binary divider (32) to a counter (47). The latter counts backwards in each case from an input number M to zero, and again from the maximum value to zero. A flipflop (53) controls this process and emits a pulse S in each case when zero is reached twice. The values E and M can be interpreted as a number in an exponential representation. The frequency range of the oscillator (23) covers a factor of approximately 2<8>. <IMAGE>