This circuit is from an1966 General Electric documentation. The Triac can be equivalent to 6 A or more, mounted on a good heatsink. Any diac can be used.
This circuit applies to other operational ones, other than the one indicated. The formulas next to the...
This circuit can source 3 to 12 V with currents up to 500 mA depending only on the transformer....
This relay circuit is intended for reversing small DC motors. The circuit is from an old...