This circuit is from the time when slide projects were used. We find it in a 90's Wels’ Think Tank. The lead times can be adjusted from 5 to 30 seconds.
Found on a 1965 Radio Electronics, this circuit fires a signal xenon lamp applied to the SCR from...
This type of amplifier can be found in many other points in this section. This is from a 70s...
This circuit is from a publication of the 70s, but it can be easily assembled with the BC548. The...