Temp. stabilised inductive proximity switch

摘要

The temp. stabilised inductive proximity switch has a transistor oscillator circuit (1,2a,2b,T1) with a current source (I1) connected in the emitter circuit of the transistor (T1) used for compensating the temp. detected temp. variations to obtain a stable switching characteristic. The temp. is detected via a temp. sensor (T3) thermally coupled to the transistor oscillator circuit. The latter contrs on associated current source (I3) and a second temp. sensor (T2) thermally coupled to the transistor (T1) within the oscillator circuit, controlling a further current source (I2), for maintaining a constant current amplification factor. Pref. each of the temp. sensors (T3,T2) uses a respective transistor.