Patent ID: 9007076
Filing Date: 2015-04-14
Classification: F02D,F02P,G01R

Abstract:
1. A method for determining the electrical resistance of a glow plug, wherein a test current is set by closed-loop control to a constant value using a constant-current source and is directed through a glow plug circuit to the glow plug, and wherein a feedback signal of the constant-current source is evaluated in order to determine a value of the electrical resistance of the glow plug, where the feedback signal goes through a feedback signal circuit connected to the constant-current source but where the feedback signal circuit does not contain the glow plug, wherein the feedback signal is evaluated by linking it to a voltage signal that is measured between the constant-current source and the glow plug with respect to a reference potential where the reference potential is a ground potential, and wherein the linking is done by a differential amplifier to which the feedback signal and the voltage signal measured between the constant-current source and the glow plug are fed.