Equivalent transistors can be used in this circuit for automotive applications in the 1980s. The frequency is given by the capacitor and the current of the lamp depends on the LM195 transistor.
We found this circuit in a 1977 publication for radio amateurs. It serves to test general purpose...
The purpose of this circuit is to amplify the signal of a medium or high impedance microphone,...
This unusual circuit from a Popular Electronics of the 90s uses LED indicators, operating as a...