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.
We found this circuit in documentation from the 1970s; The circuit uses Japanese transistors of...
This circuit goes into operation producing a sound on a small speaker when the supply voltage...
Suggested by Harris in documentation from the 80s, this circuit uses components from that time. It...