This decorative object was found in a Signetics documentation from the 60s. The circuit uses neon lamps and must be powered by a high continuous voltage. The current is extremely low.
Found in the American 73 magazine for radio amateurs, this circuit can test common quartz...
This circuit for the automatic activation of a small lamp (or high brightness LED) was found in...
This circuit provides a 5 V negative output with a maximum current of 1 A. The circuit is from the...