This an old commercial receiver found in a year 1958 magazine. The circuit uses some transformer available that timer and the transistors are germanium types. The circuit is intended to receive MW stations.
The given number circuit is used to activate the relay by interrupting the light beam that hits...
In the figure we have a simple and efficient way to obtain rectangular signals from an astounding 555...
This circuit, for 78xx series integrated devices, is suggested by Motorola in its 1990 Linear...