This circuit was found in a 90's EDN. The circuit has a well-known configuration. The voltage obtained depends on the number of diodes. Capacitors depend on the desired current.
This circuit is from a publication of the 70s, but it can be easily assembled with the BC548. The...
This very low frequency amplifier has a gain of 1,000 and was found in a 1967 documentation. The circuit is...
This transmitter was found in a 1993 documentation, but it can be assembled with operators like...