We found this solid-state relay circuit that can function as a shield in a Radio Electronics magazine from December 1989. The optocoupler is a phototransistor type.
August 2016 - Mouser Electronics is offering the development kit board Joule ™ 570x with expansion from...
In the figure we have a configuration that allows to test NPN transistors and with the addition of a...
This circuit was designed to work with the previous one in triggering a relay by the sounds picked up...