This circuit is from 1964 documentation but can be easily implemented based on current components. Input waveforms and detection are shown next to the diagram.
This source gently applies the voltage to the load, causing it to rise slowly, thus avoiding...
This circuit was found in a 1977 Signetics manual. The 556 consists of a 555 double and the...
This circuit, found in a 1994 documentation, uses 20 A 2N5448 triacs or equivalent and should be...