Is there a way to bypass shorts on a DCC layout? I saw a guy on youtube with a video series out that said lightbulbs will do it. I was wondering if anybody has tried this. Does it work? How do you keep the lights off without a short so that the layout gets full power? Anything else that will work or how to make shorts less likely on my layout?
The only way to bypass a short is to fix it. Light bulbs can act as buffers on a short but don't solve the problem that is causing the short. They "bleed off" some of vthe extra current being fed to the short circuit in an effort to avoid damage to the train and track. You will still need to fix the problem because the object is to not light the bulb at all.
I do the electrical and DCC connections for a 50 member modular club. Never had the need to use light bulbs because the DC and DCC circuit breakers have always functioned properly.
Martin Myers
I agree with the previous answer -- if you have your layout properly wired, there should never be a short except in the event of a derailment or similar problem. Short circuits during normal operation indicate incorrect wiring.
If you get a short as you cross from one block into another, one of those blocks has the wiring reversed. With DCC, crossing from one block into another with reversed wiring will cause a momentary short and stalling locomotive because of the phase difference in the command signal between the two blocks.
NHfan320 Is there a way to bypass shorts on a DCC layout? I saw a guy on youtube with a video series out that said lightbulbs will do it. I was wondering if anybody has tried this. Does it work? How do you keep the lights off without a short so that the layout gets full power? Anything else that will work or how to make shorts less likely on my layout?
Yes, it works.
I installed four tail-light bulbs, I think 1156 (I can never remember the number!) on the advice of Joe Fugate. To keep it simple, but effective, I broke my bus into four sub-buses, each sub-bus providing the power to one of the four gapped modules. None of the modules can get power, therefore, unless it comes via the sub-bus wires in pairs. Wired in series into one of the two wires linking the main bus to each sub is one of the tail-light bulbs. When a short happens on the affected module, the bulb lights. That module shuts down, but trains elsewhere continue to run.
But, as the other gentlemen have pointed out, it doesn't negate the short. The short, or the problem, still exists and must be corrected....or else the light will stay lit. Not ideal at all. All the bulb is meant to do is to protect the decoder from getting the full amperage that it would otherwise get. Much more expensive circuit breakers do an excellent job, but so far the cheapie bulbs work just fine for the two of us. I have never had a bulb blow or a decoder...at least no yet.
So, I hope you understand that this system of bulbs only mitigates the damage, it doesn't prevent, or work around, any short you may have on the layout.
-Crandell