This interesting multivibrator was found in an Italian magazine that no longer exists. This is Radio Elettronica, July 1972 edition. The circuit produces a sound whose frequency depends on the temperature of the sensor. The sensor is a thermistor and the drive can be set on the potentiometer. For TR1 we could use a BC558 and for TRF2 a BC548.

 


 

 

 

 

Datasheets


N° of component