Patent · US Expired

Threshold detection

US4308502A · kind A · utility

4Cited by
1References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 31, 1980
Grant dateDec 29, 1981
Priority date
Expiry dateMar 31, 2000

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K5/1252
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A simple and inexpensive direct current voltage level detector is shown which has a significant immunity against interfering alternating current signal components. The output of a standard analog threshold detector is successively sampled by clock pulses having twice the repetition rate of the frequency of the expected interfering alternating current components. By requiring two successive samples to be above the threshold of detection, immunity is provided against false detection due to temporarily exceeding the threshold level due solely to the positive excursion of the interfering alternating current components. Simple clock-driven flip-flops are used for the sampling and a simple logical AND gate is used to detect the successive samples.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.