Found in an EDN from the 90s, this regulator makes use of the integrated circuit of the time. The input can be from 8 to 20 V.
We found this circuit in a 90s Electronic Design. The frequency is given by the network R C1, C2....
In the figure we have a typical Wien Bridge oscillator with AGC. The negative waveform is sampled by...
This circuit was found in a Popular Electronics from 1991. The transistor could be the BC548. The...