Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
68 words
A method of controlling the heating of a glow plug of a Diesel engine, characterised by the steps of supplying a quiescent current to the plug, sensing by means of a quiescent current the resistance of the plug to determine the temperature of the plug, intermittently supplying heating current to the plug, and varying the duration of each application of heating current in dependence upon the sensed resistance.
Claim 2
Independent Claim
68 words
A method of controlling the heating of a glow plug of a Diesel engine, characterised by the steps of supplying a quiescent current to the plug, sensing by means of a quiescent current the resistance of the plug to determine the temperature of the plug, intermittently supplying heating current to the plug, and varying the duration of each application of heating current in dependence upon the sensed resistance.
Claim 3
Dependent Claim
31 words
A method according to Claim 1, wherein the duration of each application of heating current is proportional to the difference between the sensed and the desired temperature of the glow plug.
Claim 4
Dependent Claim
79 words
A control system for controlling the supply of heating current to glow plugs of a Diesel engine, characterised by means (40) for supplying a quiescent current to said group of glow plugs, sensor means (24) for sensing the resistance of said glow plugs which resistance varies with temperature, and a control means (18, 20) for applying a heating current to the glow plugs for a time dependent upon the magnitude of the resistance sensed by said sensor means (24).
Claim 5
Dependent Claim
79 words
A control system for controlling the supply of heating current to glow plugs of a Diesel engine, characterised by means (40) for supplying a quiescent current to said group of glow plugs, sensor means (24) for sensing the resistance of said glow plugs which resistance varies with temperature, and a control means (18, 20) for applying a heating current to the glow plugs for a time dependent upon the magnitude of the resistance sensed by said sensor means (24).
Claim 6
Dependent Claim
31 words
A glow plug control system as claimed in Claim 3, characterised in that the mans for supplying a quiescent current to said group of glow plugs comprises a constant current source.
Claim 7
Dependent Claim
56 words
A glow plug control system as claimed in Claim 3 or Claim 4, wherein the control means (18, 20) includes means responsive to the difference between the temperature of the glow plug as sensed by said sensor means (24) and the desired temperature and operative to control the said time interval independence upon the said difference.