This circuit was obtained from an 80s factory manual. The integrated circuits used are uncommon today, but the diagram is for reference only.
This alarm circuit is from a 1990 Electronics Handbook. Transistor Q1 can be a BD135 and the relay...
The circuit shown can be connected in parallel with the speaker of a sound system. Its purpose is to...
Using this circuit the lamps glow in sequence in a speed given by the capacitors. The SCRs present a...