We found this multiple thermostat circuit in July 1980 Radio Electronics magazine. It uses opto-triacs for power control and operates on a 117 VAC mains.
This circuit, with a 12 V input, was found in a Popular Electronics from the 1990s. Information is given...
This circuit is the equivalent of the CB121, but is triggered with the negative transition of the...
We found this circuit of a clamp-type ammeter in a Japanese documentation from the 1960s. The...