This circuit was found in a 1971s English magazine. We can still assemble it using BC548 transistor. The other components are common. The supply voltage of 6 or 12 V depends only on the relay.
We found this circuit in an American documentation from the 60s. The circuit can be made with...
This simple circuit uses few common components and can be installed in any car. In case of...
This amplifier step with a transistor has an input impedance of 100k to 10 M. The transistor can be any...