With this circuit from the September 1989 issue of Radio Electronics magazine, it is possible to receive VLF band signals on a common radio, just like the signals emitted by the previous receiver.
This circuit is from an old Japanese magazine from 1960. The circuit uses germanium transistors from the...
Found in American documentation from the 1990s, this simple circuit excites a LASER diode. The...
This circuit triggers a load that depends on the characteristics of the transistor when we touch...