Frequency and speed display device

Apparatus for indicating the frequency of a source subject to frequency changes comprising a digital display having a tendency to flicker, means responsive to the source for supplying the display with a digital signal indicative of the frequency of the source, said display supplying means including a latch circuit for storing a digital signal indicative of the frequency of the source, means for controlling the latching duration of the latch circuit as a function of changes in the frequency of the source so that the latching duration is relatively long when the frequency of the source is relatively constant and the latching duration decreases from the relatively long duration to shorter durations as the frequency of the source changes so that the flicker of the display is substantially obviated, small frequency changes at relatively constant frequency are not displayed and rapid frequency changes are relatively accurately displayed.

Apparatus for indicating the frequency of a source subject to frequency changes comprising a digital display, means responsive to the source for supplying the display with a digital signal indicative of the frequency of the source, said display supplying means including a latch circuit for storing a digital signal indicative of the frequency of the source, means for controlling the latching duration of the latch circuit as a function of changes in the frequency of the source so that the latching duration is relatively long when the frequency of the source is relatively constant and the latching duration decreases from the relatively long duration to shorter durations as the frequency of the source changes so that small frequency changes at relatively constant frequency are not displayed and rapid frequency changes are relatively accurately displayed.

Apparatus for indicating the frequency of a source subject to frequency changes comprising a display, the display being of a type requiring a memory for supplying the display with signals, means responsive to the source for supplying the display with a signal indicative of the frequency of the source, said display supplying means including a means for storing a signal indicative of the frequency of the source, means for controlling the frequency at which the storing means is responsive to the source and the frequency at which the signal stored in the storing means is supplied to the display as a function of changes in the frequency of the source so that the storing means supplies the signal stored therein relatively infrequently to the display when the frequency of the source is relatively constant and the storing means supplies the signal stored therein relatively frequently to the display as the frequency of the source changes so that small frequency changes at relatively constant frequency are not displayed and rapid frequency changes are relatively accurately displayed.