The selected circuit was found in GE's 1977 semiconductor manual. 3N84 is a controlled silicon switch and SCRs support equivalents. The transistor can be a BC558, depending on the supply voltage.
We found this circuit in the Texas Instruments opto-electronics manual. The button resets and the...
This circuit is from a 1992 documentation, but the components used can still be easily assembled. The...
This interesting amplifier for frame antenna for the medium wave range was found in a Popular...