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Snubbers


George Simmons

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I posted this question in another thread, but since it was off-topic, I thought maybe it would be better in a thread of its very own. Does it matter where one locates a snubber? Someone mentioned it should be placed at the end of a series of LED stringers, but I was under the impression that it could be placed anywhere in the circuit. So, which is the correct placement?

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I use a single C-9 as a snubber. I plug the snubber into the extension cord and the lights into the snubber cord.

Electrically it should not matter as it forms a parrallel connection and should work anywhere on the line.

Some snubbers I have seen made are only made with a male plug and no female to plug the lights into. So, of course that would have to go at the end of the string.

Chuck


Attached files 205006=11407-100_2174_1.JPG

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Disclaimer - sorry in advance if any terminology below is not perfect.

I agree, they work any where on the circuit. If using C9 bulbs, place where they will not be damaged.

To snubber or not to snubber?

There is no formula to determine whether you need snubbers in advance. Typically, the more led strings you have on a circuit, the more you need a snubber. I do a live fade test on all my led channels. If any of the led strings "hold" brightness or get twitchy during the fade, they get a snubber.

Snubber vs. resistor - To keed Dan happy. What we're actually talking about is the use of resistors, c9 bulb etc. These resistors, not snubbers, drain the extra voltage off the led strings, hence a smooth fade.

Actual snubbers drain, scrub off, excess current from spinning motors that send current back into the circuit when they lose power. This is why we don't put inflatables on LOR channels.

Dan mentioned a future controller upgrade will include both scrubbers (for motors) and resistors (for leds)

Glenn

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GS wrote:

Typically, the more led strings you have on a circuit, the more you need a snubber.

I have never understood this concept where the MORE LED's on a circuit the more need for a snubber. If there are MORE LED's on a circuit, wouldn't that cause more of a draw and hence no need for a snubber (C9 Bulb)?

I also have heard that using a snubber on LED's will prolong their life...
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jimswinder wrote:

I have never understood this concept where the MORE LED's on a circuit the more need for a snubber.

It's times like these that I wish I was more of a scholar. (But not to worry - someone who is will come along and make any necessary corrections.) It has to do with increased capacitance with multiple strings or some such gobbledy-gook. In plain English, I've found that for me anyway, one set of lights on a channel doesn't seem to cause any fading problems. But I have a few channels - roof lines for instance - where there is a few hundred lights and the fade isn't smooth and it "jumps" in intensity as it is fading down. And I have had a few LED channels of multiple light sets that don't go completely off all the time. Snubbers help these problems.
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Well George, I am no scholar or EE either. Nor do I have the test equipment to back up what I am about to say. But I do believe that your take is the same as my own. Due to with more strings you have, more wires that are twisted closely together. And what is a Cap.? Two conductors that are close together but have some isolation so that they do not short out. So the more wire you have. Greater the cap value. The resistance or as we like to call it the snubber drains the charge.

Well at least that's my take, but I could be wrong.

B_Regal snuck in while I was composing this..

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I think it is all of the "hole" charges in all the depletion regions of the LEDs cumulative junctions collapsing at once and discharging back into the line beating against the crossing point of the triac causing it to misfire slightly at certain points when conditions align just right.

Doncha think? :cool:

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terrypowerz wrote:

I think it is all of the "hole" charges in all the depletion regions of the LEDs

In this case that would amount to a pile of bull Jim... But seriously, Terry, I thought full-wave LEDs didn't have depletion regions in which the "hole" charges could even accumulate?
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  • 2 weeks later...

ok .....

So being the newbie here who has purchased a few 1,000 LEDs with the intention of fading all of them .... 1/2 of C9s and 1/2 are C6s ......

The C9s are for the roof and windows. The C6s for the mini trees and arches.

Would I be needed a snubber ( extra C9 bulb ) on each of these to fade properly.

Now I am concerned.

Thanks,

Dave

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Don't worry, led fade issues are very easily fixed.

Once setup, run a rest fade. Any twitchy string (circuit), or string that has a sudden drop should have a snubber/C9 bulb/terminator.

I wish all problems were fixed this easily.

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Thanks GS ....

It is just so hard being my first year and not yet being able to physically test things yet.

Everything has finally arrived except for the controllers so at least now I can start building my display ( In July !! )

Dave

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HI ALL,
In the Netherlands (europe) we have to do it this way.......
In my case I have some transformers in my circuit to bring the current from 220V to 12V and 24V. This means that i have to deal with a inductive load. So i used snubbers ( capasitor 0,1uF and 47ohm resistor 0,5 Watt in serie) parrallel over my outlet. This way I always have the snubber in each channel.


Here a little explanation about snubbers:


The R-C snubber inductive load suppressor should be applied as shown below. Placing the suppressor across the contact in many cases can work as well, but for maximum effect, it is best to place the suppressor directly across the load. All inductive loads in a system should be suppressed in this manner to avoid mutual interference; the suppressors are effective with both AC and DC circuits.


[align=center]application.gif[/align]




  • [align=left]Inductive Loads:
    When using relays for inductive loads such as motors, relay coils, solenoids, etc., the contacts will be subjected to high induced voltages during opening of the contacts (load circuit).
    Such high induced voltages (transients) may cause damage to the reed relay's contacts and significantly reduce its life.
    Therefore, protective circuits such as: RC (snubber), varistors or clamping diodes, are recommended. [/align]





  • [align=left]Capacitive Loads:
    When using reed relays for capacitive loads such as capacitors, incandescent lamps or long cables (harnesses), the reed relay contacts will be subjected to high surge (inrush) current.
    Therefore, protective circuits such as: surge suppressors or current limiting resistors, are recommended.[/align]


[align=left]Hopefully this will explain a little bit more. So when your lights stays on or stays a little dimmed on try the above. It will help a lot of us.[/align]

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I have been using LED stirngs for 3 years and no snubbers and no fading problems.

To snubber or not to snubber. Test your lights to determine if they fade properly then install snubbers as required.

Just my 2 cents worth

Richard

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Hello Richard,

I agree. There are led strings that just have enough load to work properly. So when you buy the strings, just test them before you add snubers to the channel outlets. When you don't need them you can save your money for other things.

In my case, the lights worked properly for half a month. Then some random channels stayed on or wouldn't fade. First one channel after a few days an other and so on. So I added snubbers to the outlet. When I ran out of snubbers I added lightbubs to the channel outlets. That works fine to.

So again. When your lights works perfectly don't add any snubbers and leave it like it is. Only when you discover the known problems on the channels this is a fine way to solve this issue.

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I totally agree with you Tom. All my LED strings are either CDI or LED Holiday Lighting.

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