A digital watch in which the numerals move beneath windows of a cover plate and possessing a reflecting element for reading the time in a direction which is at least approximately parallel to the cover plate.

A digital tracker of aircraft represented by a binary coded signal particularly suited for a midair collision avoidance system such as SECANT, an acronym of a system for separation control of aircraft by non-synchronous techniques. The tracker located on an aircraft station receives pulses, representing both interrogation responses, termed "hits," from other aircraft in the environment to "probe" interrogation signals transmitted from the station aircraft, and interrogation responses, termed "fr...

A digital clock comprising an indication section for indicating numerals which represents the time and a control section for forming required numerals. The indication section includes at least four electric lamp type numeral indicator each having seven-segmented electric bulbs which are selectively turned on or off to compose any required figure of 0 to 9. The control section includes switch means each electrically connected with corresponding one of the bulbs, and rotating drums one for each of...

A digital clock wherein minutes, tens of minutes, and hours display indicators are rotated by a motor in order to bring successive numerals into position behind a viewing window 82. Geneva gears 113 and 115 are grouped at the left of the numerals for driving an hours drum 56 and a tens of minutes numeral drum 58, and the drums are uniquely supported with respect to each other so that they may be driven by a motor 8 which is located at the right of the numerals.

A digital tachometer arrangement in which pulses resulting from rotation of a shaft, are counted over a predetermined time interval. The time interval is established by counting pulses from a high frequency oscillator. The counting of pulses from the high frequency oscillator is begun only at a predetermined instant when the pulses from the rotating shaft attain a positive edge. Relating the beginning of the time interval precisely to a predetermine edge of the pulses from the rotating shaft, pr...

An analog to digital converter for use in a digital voltmeter includes a periodic source of reference signal in ramp form starting at a negative potential and increasing to a given positive potential. The ramp signal and an analog signal to be measured form the inputs for a first comparator which provides a given output level as long as the ramp signal is less than the analog signal. A source of clock signals and the output of the first comparator are connected to a first logic circuit which pro...

A monitor for checking a plurality of multi-bit digital patterns generated by a system being monitored to determine that each pattern is valid, that each of the patterns appear in the right sequence and that the total number of valid patterns detected during the testing cycle is as expected is disclosed. Additionally, the bit patterns are monitored to detect unexpected transitions. The results of these tests are then combined to form a composite malfunction signal indicative of the operational s...

A digital tachometer which can operate to count the revolutions of any rotating device for which an electrical signal the frequency of which is related to the speed of rotation can be obtained is disclosed. The tachometer includes means for `normalizing` the input signal to provide a pulsed signal having a predetermined relationship with the speed of rotation, main counting means for counting the pulses, and means for displaying the accumulated count. The counters are controlled by logic circuit...

A digital time indicating clock with minutes, tens of minutes and hours numeral indicating drums arranged in an array, in which intermittent rotations of the minutes drum as driven by a clock mechanism are transmitted sequentially intermittently to the tens of minutes and hours drums through time numeral shifting-up mechanism which comprising a first pinion being rotatable about a shaft borne in proximity and parallelly to peripheries of the resepctive drums and meshing with gear teeth on a peri...

The invention covers a precision digital filter for signal samples represented in a digital form. The flow of samples x.sub.o, x.sub.1, x.sub.2, . . . x.sub.n, of the signal is split into blocks of a fixed length which are simultaneously transmitted to two circular convolution generators operating to different prime number modulos. The outputs of the generators are each submitted to a correcting device and the corresponding corrected terms are added. The added terms are each then added to a dela...