For low-frequency signals, this circuit transforms a single oscilloscope into a dual-trace. The circuit is from Radio Electronics magazine, October 1984.
This control for 1200 W of power was found in the documentation of General Electric of 1966 has a...
I found this circuit in an old English magazine from 1979, but it can be easily assembled with...
This circuit imitates the singing of a bird intermittently with the intermittency determined by C1...