This old voice circuit suitable for telephones of the time was found in a Radio Electronics from September 1973. The circuit is powered by a voltage of 7 V.
We found this circuit in an old documentation. The instrument can be an ordinary multimeter in the...
This simple electroscope with bipolar transistors is not the most sensitive, but can detect static...
This circuit was found in an old Popular Electronics. It causes an LED to pulse and, at the same...