With this circuit it is possible to obtain a voltage of -5 V from a 5 V source. The circuit is from Radio Electronics from May 1982. The maximum current is around 80 mA.
This good quality stereo amplifier was found in a Japanese publication from the 1960s. The circuit...
This circuit allows you to use the parallel PC interface to control LEDs. The circuit was found in...
This circuit, with printed circuit board, is from an article in Radio Electronics magazine from...