In order to meet environmental legislation requiring improved SI engine fuel economy and exhaust emission it is likely that the conventional contact breaker with centrifugal and vacuum advance will be replaced by microcomputer-based systems. Digital computing techniques combined with engine sensors can be used as a means of implementing such requirements. The techniques used in the Hughes computer-based ignition system are based on the principle that after computing the required ignition advance angle the correct value of primary coil current is then available prior to spark demand. In practice the Hughes system offers three precharge speed bands, one for cranking speeds and two pre-programmed speed bands up to maximum rpm to supply defined spark energy requirements. Details are given of system design and operating characteristics. /TRRL/

  • Availability:
  • Corporate Authors:

    Morgan-Grampian Limited

    30 Calderwood Street
    London SE18 6QH,   England 
  • Authors:
    • Fowler, A L
  • Publication Date: 1979-2

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00194983
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Jul 11 1979 12:00AM