The figure shows how to couple two TTL circuits using an optical coupler to obtain isolation. The circuit is shown in the August 1992 issue of Radio Electronics magazine.
This circuit was found in an American 1980s documentation. The components are current but most...
Found in a Popular Electronics from the 90s, this circuit applies to flashes with xenon lamps. The...
Found in old documentation for radio amateurs, this circuit is intended to excite a MOSFET on the...