What do these components do

[Jeffl]

I'm looking at the PCB dongle and I'm trying to figure out what a few of the parts do.

NMR100C dc/dc converter

6N137 Logic Output Optocoupler


I'm just curious, trying to understand how it works.  

Thanks Jeff

[tbone321]

The NMR100C assures that the circuit gets its 5V and the optocoupler isolates the dongles logic circuitry from the outside world.

[n1ist]

The NMR100C is an isolated DC-DC converter.  It takes the 5V from your computer (via the USB cable), and generates an isolated (no connections between in and out) 5V to power the DMX cable side of the dongle.

Between it and the optoisolators, the part of the circuit connected to the DMX world is not electrically connected to the part of the circuit connected to your computer.  If there was a short circuit or other problem out in your yard, even between the low voltage signals and the AC power line, these parts would protect your computer from damage.
/mike

[Jeffl]

Thanks for the explanations and education.  This all makes sense now.