The integrated circuits used in this thermometer are not very common today. The indicator is a microammeter for a scale from 0 to 100o C. The supply must be made with a voltage of 1 to 12 V.
We found this symmetrical regulator in a documentation from the 70s. The circuit uses components...
This circuit was found in a 1995 documentation. It drives a set of sequential LEDs from the sound...
This sophisticated remote field strength meter circuit was found in a 73 magazine for radio...