What on earth is a "channel monitor"? Images of gigantic ocean-going vessels quickly form on their way through the Kiel Canal, saving themselves the 250-mile detour through the North Sea, Skagerrak and Kattegat. And because the pilot prefers to check his message status on his smartphone instead of doing his actual work, he only monitors the channel passage selectively!If circuit breakers do not workWhile this is a nice interpretation of "selective channel monitoring", it is simply wrong. Experts who have spent hours troubleshooting a machine know this. This is particularly costly in complex systems in which switched power supplies electronically regulate the voltage and current at the output.It is possible that, in the event of a short circuit or overload, secondary fuses react more slowly than the power supply unit and therefore, this selectivity is not applicable. This leads to critical situations, such as voltage dips, and, in the worst case, even to cable fires. But how is it possible that these downstream protective devices do not react? This requires us to look back almost 30 years.Convincing argument: High short circuit protectionIt was at the beginning of the 1990s when a change in the mechanical and plant engineering industry was about to take place: the change from transformers to electronic power supplies. At the beginning, only a small group of people dared to take advantage of the new devices. A regulated 24V DC voltage and short circuit protection according to a fixed defined characteristic curve obviously sounded too good to be true for potential users!However, the rise of electronically regulated power supplies was unstoppable from then on, as more and more OEMs wanted to benefit from their advantages.
Read the full article in the November issue of PBSI
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