This simple audio signal tracer or follower can be made with a BC548 instead of the original transistor. The output is made in a small crystal phone. The power can be from 5 to 9V.
This circuit controls the brightness of a 12 V powered car courtesy light. The transistor can also...
This circuit is from the 80's component manual itself, but can be applied to more modern...
We found this circuit in the Linear Applications Handbook by National Semiconductor. It uses the...