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 configuration can be found in other articles on this site. This is from European...
This 18 V x 300 mA power supply was found in a 1969 documentation. The integrated circuit is...
This experimental 555 circuit sends signals in the medium wave band to a receiver a few meters away....