Patent · US Expired

Lockproof low level oscillator using digital components

US4987389A · kind A · utility

4Cited by
26References
22Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 2, 1990
Grant dateJan 22, 1991
Priority date
Expiry dateApr 2, 2010

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S331/03
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

Three series connected inverters (38, 40, 42) are attached to a tank circuit (18) which includes an inductance (12, 14) and a capacitance (16, 17). Negative (38) biases the inverters at the midpoint between the bistable low and high logic level states. Positive feedback from the second inverter (40) to the tank circuit induces oscillation in the tank circuit. The negative feedback is decoupled at the resonant frequency and the energy delivered to the tank circuit from the positive feedback maintains a low level oscillation in the tank circuit. Negative feedback around the three inverter digital circuit prevents lockup in the event of power loss or momentary short.

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