Digital signal selective circuit

Details Digital signal selective circuit Digital signal selective circuit

1978-05-25

1980-11-04

Heyman, John S.

Communications: electrical

Land vehicle alarms or indicators

Internal alarm or indicator responsive to a condition of the...

328141, 328129, 340171R, 329126, 328119, H03K 5153, H03K 1300, H03K 906

Patent

active

042322677

ABSTRACT:
A digital signal selective or detecting circuit which is responsive to a periodic input signal having a frequency within a specified range, such as an audio frequency used as a cueing signal in a VTR, only when the signal in such frequency range exists for a predetermined time; includes a clock pulse generator providing reference clock pulses, a first counting circuit counting the reference clock pulses whenever the periodic signal is present, a circuit providing a counting pulse whenever an operating characteristic of the periodic signal, such as the transition between its positive and negative portions, occurs at a time when the count in the first counting circuit is between first and second predetermined counts, and a second counting circuit counting each counting pulse and providing an output when the second counting circuit attains a predetermined count. Preferably a Schmitt trigger is employed for shaping the periodic input signal, and a JK bistable multivibrator is associated with the Schmitt trigger and the clock pulse generator for synchronizing the output of the Schmitt trigger with the reference clock pulses.

REFERENCES:
patent: 3044065 (1962-07-01), Barney et al.
patent: 3579126 (1971-05-01), Paul
patent: 3660842 (1972-05-01), Ballantyne
patent: 3745475 (1973-07-01), Turner
patent: 3868845 (1975-03-01), Shimizu
patent: 4052676 (1977-10-01), Crittenden
patent: 4158148 (1979-06-01), Teller

Affiliated with

Also associated with

Rating

Digital signal selective circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Digital signal selective circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Digital signal selective circuit will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1647498