This circuit is from 1975 documentation. Transistors such as 2N3055 can be used and the transformer is of a special type. R1 is 200 ohms and R2 is 10 ohms.
We found this circuit in the On Semiconductor thyristor manual. He makes use of a triac and a PUT....
This 80's circuit uses a light-sensitive SCR or LASCR and a one-sided silicon switch SUS, uncommon...
Using an RCA CA3018 as a base, this circuit has a sensitivity of 2 Mohms per volt. The circuit is from a...