This circuit was found in a 1964 Electronic Design. The circuit delays the firing of a load for a time given by RC. The SCR must be in accordance with the controlled load.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...