CIRCUIT FOR CONTROLLING GLOW PLUG ENERGIZATION

In a glow plug energization control circuit wherein the output voltage produced from a glow plug temperature simulator composed of a charging/discharging circuit is compared with a reference voltage from a reference voltage generator and heating of the glow plug is controlled in accordance with the result of the comparison, the voltage developed across the glow plug is applied to the charging/discharging circuit to charge a capacitor thereof and the level of the reference voltage is changed in response to changes in the voltage of the voltage source by which the glow plug is heated.