Temp. sensor function control system

摘要

The temp. sensor function control system responds to a given temp. rise indicated by the evaluation circuit for the temp. sensor signal, to allow a superimposed AC voltage providing self-heating to be disconnected. Pref. the temp. sensor (1) is coupled to the evaluation circuit via a low pass filter (29).The AC voltage source (25) is connected to the line between the sensor and the filter, via a capacitor (28). The AC voltage source pref. comprises a variable oscillator, controlled via a NOR logic (21) coupled at one input to a comparator (17) comparing the output voltages of the filter and the evaluation circuit.