This simple SCR trigger was found in a 1965 General Electric SCR manual. The circuit makes use of a diac, and the transistor supports an equivalent.
Available at Mouser Electronics this component of Diodes Incorporated consists of a voltage...
Found in Radio Electronics this circuit uses a fotodiac to drive a triac. The circuit can use...
The first circuit was suggested by Analog Devices (www.analog.com) in its Application Note AN-411...