Bench thermometer (CB20501E)

With an ultra-low consumption, this circuit can be powered by solar cells. The circuit is from a 1991 documentation.

Transistorized receiver (CB22218E)
We found this circuit in a documentation from the 50s. It is based on CK722 germanium transistors. The...
60's crystal radio (CB22171E)
Found in an English publication from the 1960s, this circuit uses period components, including the...
TTL Oscillator (CB6150E)
This oscillator can generate 2 to 10 MHz signals and was found in an American 1980s documentation. The...