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.
This circuit is used to cut the “click” in the loudspeaker of amplifiers when they are turned on....
Found in RCA documentation from the 1970s, this circuit is intended for firing thyristors in inverter...
In the figure we have the way to control a TIC series triac with a reed switch. The current in the...