This circuit was found in a documentation for radio amateurs from the year 70. Its purpose is to produce a tone on a transducer when transmitting messages in SSB telegraphy.
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....