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.
The CK722 transistor used in this circuit is one of the first commercial types in the world. The...
This automatic dimmer for incandescent lamps was found in a European publication from the 1980s. The...
This traditional doubler configuration with the 555 can be found in other articles on the author’s site....