This circuit was found in a 1975 documentation. Current general-purpose transistors can be used, and the power is supplied with relatively high voltage. The gain is 30 dB.
This alarm oscillator was found in the December 1974 issue of Radio Electronics magazine. The...
We found this small audio amplifier in the November 1999 issue of Electronics Now magazine. The...
This circuit is a continuation of the previous one, serving as a protector against overloads in...