This circuit is from an American documentation from the 90s. The transistors are of power and must be equipped with good heat sinks as well as the integrated voltage regulator.
This circuit uses an optocoupler with a phototriac or optotriac to drive an external triac. The...
The circuit in figure 1 is a dynamic test for FETs. The characteristic of a FET is displayed in...
This circuit was found in a 1965 Radio Shack documentation. The transistors are from that time....