Found in a Popular Electronics from the 90s, this circuit uses common components with several operational options, including the use of an optocoupler that allows its application in a shield.
Found in Popular Electronics of January/February 1969, this transmitter has a few meters range and can...
Found in 1969 RCA documentation, this circuit maintains constant current in the filament of a lamp...
Found in a 90s 73 magazine, this circuit uses an unusual component today which is the XR2206. |...