Two transistors on a regenerative switch are used to trigger a triac. This circuit is from the RCA Power Circuits manual. Transistors admit equivalents.
We found this circuit in a 1987 documentation, but it can still be easily assembled. Its output must...
This circuit that emits siren sound can be used in a fire alarm. We found it in an old American...
Found elsewhere in this section, this circuit is from the April 1971 Radio Electronics magazine. Note...