Found in an American brochure from the 90s, this circuit shows how we can implement a 4-input AND gate with relays and switches.
We found this chopper circuit in a 1967 publication. The transistors are of the time, and current...
Using neon lamps, this regulator was found in a1969’s documentation. The lamps are types available...
Found in Popular Electronics from the 90s, this circuit generates a 1 kHz signal. The coil is from an...