detail of data links galvanic isolation on retro circuit board with old electronic components

automatic black board brown capacitance capacitor carbon ceramic circuit closeup component components data design detail device diagonal diode disposal ecology electric electrical electronic electrotechnics element emitting engineering ewaste galvanic green hardware industrial industry inside interface isolation isolator led light line link macro metallized network nobody nopeople old optical optocoupler optoisolator part pcb photocoupler photodiode photosensitive power recycling red resistor retro row semiconductor signal soldered sorting switching technical technology transfer transistor vintage waste white wire