Circuit element to determine deviation in frequency - uses two NOR gates to form two signals revealing deviation of frequency from nominal value

摘要

Deviation determination of an actual frequency from a nominal frequency is by the use of two signals. Both frequencies relate to rectangular waveform oscillations. The first signal determines the value and the second signal determines the direction. The nominal frequency is compared with the actual frequency divided by an integral factor. The phase of the divided actual frequency for determining the direction is out of phase in comparison with the phase of the divided actual frequency. With the aid of one (G1) of two NOR-gates (G1, G2) the rectangular oscillations (a, b) i.e. nominal and divided actual frequencies are compared.