Found in an Electronics World of 1968 this circuit can use current SCRs and the diodes are according to the lamp. The Circuit only works with incandescent lamps.
In this circuit of a 1968 publication the unijunction may be 2N2646 and the transistor BC548. The...
The purpose of this circuit is to improve a trigger circuit using a zener diode. The circuit was...
This interesting circuit of the American publication Electronics Handbook Volume XIII 1993 shows a...