Re: Hot Snubber

jazzmanlj
 

Rich,

>No, the bus wires are not twisted, and the two bus wires are pretty much right next to each other.
As I suspected! Having the wires as you describe increases the parasitic inductance and capacitance! These cause problems
>Regarding the hot snubber, I would have never noticed it except for the fact that I was working on some >wiring under the layout and happened to notice it. I wonder how many modelers ever check the snubbers >since they are under the layout, out of sight and out of mind.
Probably true for the majority of modelers. The anamolies are hard to see without instruments like an Oscope.
>I cannot help but wonder, why this particular snubber? If "the snubber is doing its job as intended", what is it >doing, and how would it be noticed except by chance.
It is supressing voltage spikes that seem higher than usual. That is it's main job!  As to why, every layout is unique to itself. No different than any piece of switching electronics. This is what engineers deal with all the time.
Do a Google search on 'snubber waveforms'. Lots of pictures so all can get a better understanding of what a snubber does and why it is needed in certain circumstances.
>I go back to my original question. Why is this particular snubber hot, and is it anything to be concerned about?
Yes you should be concerned. Voltage spikes are undesired and can cause problems and even destroy decoders that are not protected(poorly designed)!
>I really appreciate all of the help and attention that this thread has brought on, but I remain mystified as to >whether I have a problem and, if I do, how to fix it.
Twist all your main buss wires. You can do a section at a time and at least feel if a snubber gets a bit cooler.
Keep any sensitive wires such as control away from the power wires, and if you have control/signal wires of any length then twisting is a must. Shall be twisted.
 
Hope this helps,
Len Jaskiewicz


 

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