Temperature monitoring device with energy supplied by a thermocouple

摘要

For monitoring the temperature and indicating overheating of the temperature of a motor vehicle exhaust gas catalyser, a thermocouple used as a sensor for high temperatures is used both for supplying energy to evaluation electronics connected downstream and as a temperature sensor element. The evaluation is carried out by means of a pulse generator used as an interrupting switch, which interrupts the thermocurrent flowing through an induction coil, a temperature evaluation signal being derived from the induced voltage surge. The pulse generator is supplied with external energy via a signal lead in at least the initial phase of the measurement.