Double Button Spurious Signals Prevention Circuit.

Abstract

An analog circuit prevents spurious signals when two buttons are simultaneously pressed in a digital signaling telephone keyboard (telephone console). The analog circuit includes a group of pull-up resistors, with one resistor connected to the high switch contact associated with each button; a responsive resistor connected between the pull-up resistors and a voltage source; an operational amplifier whose inputs are connected to a threshold reference voltage and to the responsive resistor; and a circuit, including a zener diode, connected at the output of the operational amplifier for TTL voltage compatibility. (Author)

Document Details

Document Type
Technical Report
Publication Date
May 04, 1979
Accession Number
ADD006283

Entities

People

  • Robert B. Kelleher Jr

Organizations

  • United States Army

Tags

DTIC Thesaurus Topics

  • Amplifiers
  • Consoles
  • Diodes
  • Electronic Components
  • Electronic Equipment
  • Keyboards
  • Operational Amplifiers
  • Resistors
  • Zener Diodes

Fields of Study

  • Physics

Readers

  • Computer Science/Computer Engineering/Data Science/Digital Signal Processing.
  • Semiconductor Device Technology