The circuit shown is from National Semiconductor, having been found in the 1994 Linear Application Handbook. Rt and Ct determine the output frequency.
This timer circuit was found in a 1980s American documentation. Transistors and SCR support modern...
Using transistors at the time, this circuit was found in a 1967 Ferranti documentation. The...
This circuit is from a 1969 General Electric manual. The SCR may be the TIC106. Similar circuits...