Patent · US Expired

Temperature sensitive relaxation oscillator

US4185253A · kind A · utility

4Cited by
5References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 27, 1978
Grant dateJan 22, 1980
Priority date
Expiry dateSep 27, 1998

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K3/352
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A temperature sensitive thyristor is incorporated in a relaxation oscillator to provide active temperature sensing. As temperature decreases, the breakover voltage V.sub.BO of the thyristor increases, and when V.sub.BO becomes greater than the supply voltage, oscillations will cease, thus providing a low temperature alarm point. As temperature increases, V.sub.BO decreases and the amplitude of oscillation diminishes, thus providing a high temperature alarm point. This is a "fail-safe" arrangement because component failure also provides a warning condition (absence of oscillation). Frequency of oscillation may also be sensed as an indication of temperature.

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