In a previous article, I wrote about generating negative voltages via a standard unipolar dc power supply outfitted with polarity-reversal relays (see “Turn Positive Voltages Negative With Relays”).

Non-return-to-zero (NRZ), non-return-to-zero-inverted (NRZI), return-to-zero (RZ), and Manchester are popular serial encoding mechanisms. Each has different characteristics that make it useful in ...