Found in American documentation from the 1980s, this circuit makes use of components of the time, which are uncommon today. The circuit detects the approach using a sensor formed by metal plates.
I found this circuit in a doc umentation from the year 1968. It uses germanium transistor and has...
This circuit produces sounds that depend on the measured voltage and that can be compared with a...
This circuit was found in American documentation from the 90s. It serves as an amplifier for a...