System for controlling the temperature of a hot spot or a glow plug in an internal combustion engine

A starting resistance system for a diesel engine having a plurality of cylinders, said system comprising a glow plug in each cylinder, electrical heaters in each of said glow plugs, means for supplying electrical current to said heaters and means for controlling said current supplying means so that a predetermined maximum current flows through said glow plugs during an engine start beginning when the engine is at ambient temperature and said current is subject to be reduced in value in a manner dependent on engine operating parameters after the engine is started, siad controlling means including:

• means for producing a first engine operating parameter electrical signal representative of the amount of fuel supplied to said cylinders for a firing cycle of the engine;
• means for producing a second engine operating parameter electrical signal representative of engine intake air temperature;
• means for producing a third engine operating parameter electrical signal representative of engine operating temperature;
• means for producing a signal (UG) representative of an energization parameter of said glow plugs;
• means for correlating said first, second and third engine operating parameter electrical signals together with said signal (UG) representative of an energization parameter of said glow plugs to produce a control signal (CS), and
• means for applying said control signal to control said current supplying means in a manner maintaining said energization parameter of said glow plugs within a predetermine range of values thereof.