This circuit was found in an Elektor from the 90s. It makes use of digital CMOS integrated devices common today. The signal is controlled automatically sequentially.
This circuit is temperature stabilized. Modern equivalent transistors can be used, and the power...
This circuit uses an optocoupler to obtain a solid state relay whose power depends on the Triac...
This power step for relay activation was found in the 1964 RCA transistors manual. The circuit is of the...