Found elsewhere in this section, but from other sources, this circuit is from a 1964 Electronic Design. The transistor is from the era and the power voltage depends on this component.
This circuit is from a publication from the 70s, but it can be assembled with any diac and a Triac...
This circuit was obtained in a 1983 publication. It is a 1-transistor voltmeter, capable of...
This circuit from Radio Electronics magazine, March 1994 edition uses two LM388 bridged, providing a 4...