This circuit was found in an ancient American documentation. The power supply is not given, but we have the voltages used. The relay is sensitive type for high voltage.
This circuit was found in a 1968’s publication and uses germanium transistors. Equivalents can be...
I found this circuit in an article in a 2003 publication. The circuit is an example of how to...
This 40-second timer uses common components. The output can be used to excite a power stage. With...