This hi-fi amplifier is from a 1975 RCA tube manual. The critical components are the transformers. Power supply is included.
This modulator circuit for AM transmitters was found in a 1960 Sylvania transistor manual. Modern...
circuit is used to increase the sensivity of a relay. A 50 to 100 mA relay can be triggered with...
We find this circuit in an Electronics Now. The indication of the logic level is done on a...