This circuit allows you to read resistors up to 20 M ohms, converting it into voltage. The circuit is from the 90s. The operational ones used admit modern equivalents.
We found this circuit in a 1976 documentation, but it can still be easily assembled using BC548...
This circuit of an old publication produces the insect-like noise that drives them away. The...
This circuit aims to increase the selectivity of receivers whose FI is 455 kHz. The circuit is...