Comments by "SeanBZA" (@SeanBZA) on "TOSLINK: That one consumer fiber optic standard" video.

  1. Easy enough to make a TOSLINK bi directional with no need for 2 cables. Just use a beam splitter mirror ( cheap ones common in CD/DVD pick up units) in each side to split the beam into a transmit and receive side, isolating them from each other. No other changes other than a more complex socket side. Coax cable for SPDIF generally included a small isolation transformer on the transmit side, to provide electrical isolation so that you would not have common mode voltages on the transmitted data. Very important if your system is double insulated, and the inside electronics are floating at some potential around half mains voltage because of the power supply Class Y noise filter capacitors. Thus your SPDIF output needs to have the electrical withstand and creepage distances for a double isolated enclosure, as the output side could be a grounded cable to equipment. It also needed RF filtering between the 2 sides, along with a high voltage discharge resistor to bleed off static charge. It needs to withstand 2kV applied, making it more expensive than the plastic optical fibre, which is inherently ( provided your socket is not gold plated ironically) a metal free construction. A lot of equipment also had both SPDIF outputs along with TOSLINK, both being provided by a single chip driver. Receivers either had a switch to select them, or used an electronic switch on the receiver to do so.
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