Light Synchronization (or lack thereof)

[weatherdan882002]

I've noticed on YouTube that with a lot of the Flagstaff vids (most noticably, this one and this one) that the lights aren't in sync. What's odd is that I have seen vids where they ARE in sync (timing slightly off, but for the most part they are in sync). Common sense tells me that it's something in the wiring, which may be why in the third vid, one side of the crossing shuts off before the other (normally all the lights shut off at once, even if one or more of the gates are still rising).

Anyway, I've never seen anything like this in my area. Does anyone know how light synchronzation occurs and how it can get out-of-sync?

[owensri]

That's because they used seperate flasher relays...

[weatherdan882002]

Is there a limit as to how many lights can go to a single relay? Also, is there a way to synchronize the relays?

[Robert_Gift]

Is there a limit as to how many lights can go to a single relay? Also, is there a way to synchronize the relays?

If an old flasherelay meant for incandescent lights, it should handle ALL of the LED lamps, which total a fraction of what incandescent lamps draw.
Perhaps these were originally incandescent lamps necessitating two relays to handle the load.

[cabman701]

On this crossing here:

http://maps.google.com/maps?f=q&source= ... 5,,0,-1.77

Each signal has always flashed independently for some reason. Can't understand why they would need to do that since there are only the 2 mast signals, a pair of sidelights for each direction on the closest signal, and one set of sidelights on the furthest signal (total of 7 sets of lights).

I'll try to grab a video of them sometime...

[illinoistrains]

On this crossing here:

http://maps.google.com/maps?f=q&source= ... 5,,0,-1.77

Each signal has always flashed independently for some reason. Can't understand why they would need to do that since there are only the 2 mast signals, a pair of sidelights for each direction on the closest signal, and one set of sidelights on the furthest signal (total of 7 sets of lights).

I'll try to grab a video of them sometime...

I have some pictures of that crossing that i will submit after the first of the year, it also has an inverted "# tracks" sign.

[SantaFebuff]

The flasher relays seem to be incorrectly maintained or installed. If they have separate relays, then one of them may be faulty.

I have little knowledge of this subject, but offsets such as this are a tell-tale sign of a bad flasher, or incorrect setup.

Here, you will see a proper and improper setup:


A proper setup will give both the signals power, but have the flasher dictate which light sets gets the power. (left or right sets) In a case of improper setup, the power itself is dictated by the flasher. The downfall of that, means that in case of flasher failure, the signal will fail to activate. If the signal is setup correctly, both lights will dimly be lite.

Here, another diagram, shows the outcomes of flasher failure with both installations:


A good way to see which signal flasher is faulty, would involve the signal maintainer doing a controlled flasher malfunction test. Where he/she should test how the signals react when the flasher is disconnected or in case it was to fail. Seeing which signal fails to light would be a dead give away.

Until then, the signals will be out of sync until something is done... or worse, a failure. It's a good thing it's obvious one signal works properly. Sometimes, both signals will be installed incorrectly, going unnoticed by a bad maintainer and/or people unable to tell if the flasher is faulty. Then, one day, the signals may just fail to activate. Luckily, these sort of things don't happen often. Even if they are installed incorrectly, a good maintainer keeping the flasher in good shape will even make this sort of thing not a problem. It's more or less a way to making sure there's a fail-safe. If someone could, I would let the railroad know there is bad setup there. It may be a delay in activation times, but I don't know.

- For more information, read here: http://matt.zont.org/signals/crossings/ ... works.html -

Cheers,
Joshua

[Robert_Gift]

Interesting!

How bright would the lamps be witheir filaments in series?
I would like to see that.

Would LED lampstill appear at FULL brightness if relay failure?

Th.is how I wired theadlight wig-wag flashers on our medical transport vehicle.
Not because of a flasher failure but because it softens the filament shock
from power being applied and turned off.

Thank you for your well-done illustration.

[SantaFebuff]

Thank you for your well-done illustration.

The illustrations are from the website link included in my previous post. I thought they were very well done too.

I am not sure how it would affect the filament. The broken relay would definitely be easier, but yet again, for regular service, incandescent lights last for quite some time. For LEDs, I'm sure there would be a dimmer look, or at least both light sets would be active at the same time. A possible dimmer look would be from the additional power draw from all lights being active, instead of just one set at a time. Either way, both lights would be active, and that's what's important for the fail-safe.

If you are really curious, you could perhaps ask a manufacture of railroad crossing LED light inserts, or a signal maintainer.

Cheers,
Joshua

[Robert_Gift]

... I am not sure how it would affect the filament. The broken relay would definitely be easier, but yet again, for regular service, incandescent lights last for quite some time. For LEDs, I'm sure there would be a dimmer look, or at least both light sets would be active at the same time. A possible dimmer look would be from the additional power draw from all lights being active, instead of just one set at a time. Either way, both lights would be active, and that's what's important for the fail-safe.
Cheers,
Joshua

For the brief moments the contact is open, electricity will conducthrough both filaments, softening the inrush current into the cold filament.
That may help it last longer. Or not.
Would like to see if there is a noticeable difference.

I suspect LEDs will appear the same brightness.

I never thoughthathe railroad flasher relay could fail in the middle. Thought it would be one side or the other.