This circuit was suggested by Signetics in 1980s documentation. The circuit makes use of the hard-to-obtain component of our day. It is for reference only.
This dual adjustable power supply was found in the June 1990 issue of Radio Electronics magazine....
We found this simple alarm circuit in a 1986 documentation. The circuit uses sensors of the NA...
This circuit, from a 1973 documentation, can be made with BC549 transistors. The frequency depends on...