Patent · US Expired

Optical transmitter for producing an optical signal indicative of temperature

US5374822A · kind A · utility

2Cited by
2References
11Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 24, 1991
Grant dateDec 20, 1994
Priority date
Expiry dateJun 24, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01K1/024
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An optical transmitter for converting a thermocouple voltage into an optical pulse train and a low pass input filter are contained in respective spaces in a soft magnetic housing. The input filter is in lead wires from a thermocouple whose hot junction is embedded in the tip of the insulator of a spark plug of an internal combustion engine. The housing itself forms part of or is connected to the H.T. lead to the centre electrode of the spark plug. The housing is surrounded by insulating material which is itself surrounded by an earthed screening casing. The low pass filter is symmetrically constructed, both electrically and mechanically. The filter prevents interference from reaching the circuitry of the optical transmitter and the housing and the casing prevents the generation and transmission of radio interference.

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