This static switch or triac contactor was obtained from Philips 1969 documentation. The SCR is from the era, but modern equivalents depending on the load can be used.
This Popular Electronics circuit can be found in various versions on this site and in this...
Found in a 1964 CQ magazine this circuit consists of an automatic telegraphic key, providing the...
This fourth-order circuit was found on an 80's Radio Electronics. The power supply must be...