This interesting 1924 triode tube receiver was found in a documentation by Gernsback. Observe supply voltages. Coils are for tuned wavebands.
This is basically the same circuit as the previous one, but using PNP transistors. In the original...
This circuit was found in a 2005 Linear Technology component manual. The circuit is full bridge...
This alarm circuit is from a 1987 publication, however the components used are still modern. The...