This circuit was found in a 1966 EEE. What it does is it converts the logic levels of 0 V and +4 V into -6 V and +6 V. Some older type transistors can be replaced by modern equivalents.
We found this circuit in a 1986 documentation. It causes 40 LEDs to flash sequentially. The big...
Exciting a sequential circuit with the output of a stereo we can make a set of lamps run at a...
This alarm from an old 1978 publication uses PNP transistors and driver and output transformers that are...