DiyLightAnimation
Hardware => Lynx Smart String => Topic started by: salongaopm on September 30, 2013,
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the 100ohm resistor in ss Hub is very hot that i think it made a burnt mark on the board. is this something to be expected? please see attached picture.
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The 100 ohm resistor is not the correct value. It is supposed to be a 150 ohm resistor. Yes it does get hot but the 100 ohm actually gets hot enough to unsolder itself from the board. The purpose of this resistor is to put a load on the PS so that the regulators work properly. 100 ohms draws way too much current. Don't continue to use the hub this way or you may end up damaging the board. You can get the correct resistor from Radio Shack.
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http://www.mouser.com/Search/ProductDetail.aspx?R=PR03000201000JAC00virtualkey59420000virtualkey594-5093NW100R0J
100 ohm 3W
The solder joints look a little "cold" but may be from the resistor warming. Desolder and reapply.
On our boards I raised the 100 ohm about 3/8" 1/2" off the PCB.
:) joe
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The WIKI shows it as a 150 ohm resistor and that is what mine have. now that I think about it, it may have been a 50 ohm resistor that unsoldered itself from a few boards. I still believe that 100 ohm is still too low and draws way more current and gets much hotter than it needs to.
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The WIKI shows it as a 150 ohm resistor and that is what mine have. now that I think about it, it may have been a 50 ohm resistor that unsoldered itself from a few boards. I still believe that 100 ohm is still too low and draws way more current and gets much hotter than it needs to.
I know the first coop of the etherdongle had a 49k resistor that unsolder itself.
Rick R.
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Are we talking about the Smart Hub? The WIKI shows 100 ohm (as does Mouser BOM, the link above) and the hubs I have here have 100 ohms. If they are supposed to be 150 ohm I missed the parade. If we're not talking about the Smart Hub then I'm a Pepsi short of having a complete morning.
:) joe
(Was "were" not "we're" proving I was a Pepsi short!) :)
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check the resistor with your multi meter to see it it's still 100 ohms.
it might be off spec, or something might have happened to it.
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Are we talking about the Smart Hub? The WIKI shows 100 ohm (as does Mouser BOM, the link above) and the hubs I have here have 100 ohms. If they are supposed to be 150 ohm I missed the parade. If were not talking about the Smart Hub then I'm a Pepsi short of having a complete morning.
:) joe
LOL, you are correct, mine does have the 100 ohm resistor installed. I seem to have way to many things going on to keep things straight. Like Rick said, it was the 50 ohm (47 ohm) resistor that decided to remove itself from the boards that it was installed on. The correct resistor does get hot but I don't remember mine getting hot enough to scorch the board. As Chris suggested, I would measure the actual resistance and make sure that the resistor is in spec.
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No comment on the resistor value but mine also gets hot like "the waitress warned me the plates were hot but I didn't believe here so I touched it and now I have a 1st degree burn" hot... But, no burns on board or issues with desoldering...
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check the resistor with your multi meter to see it it's still 100 ohms.
it might be off spec, or something might have happened to it.
i will check it afterwork tomorrow morning.
you are probably right that it is off spec base on this thread http://diylightanimation.com/index.php?topic=4408.645 (http://diylightanimation.com/index.php?topic=4408.645)
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100 ohm is correct. the wrong ones sent out where 15 ohm. they would desolder themselves fairly quick.
they will get fairly hot so you do not want to touch them. They are 100 ohm because some Power Supplies do not regulate very well without a decent load and so if your lights are all turned off you need a good load on the power supply.
RJ
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The 100 ohm resistor is rated at 3 watts and is dissipating 1.44 watts.
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i am getting a reading of 18 :(
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You need to remove one of the legs from the board to get an accurate reading. Measuring the resistance with the fuse installed then also measures the resistance of the rest of the circuits that the resistor in in parallel with. If it is really 18 ohms then you would need to remove and replace it anyway so you can start by removing one leg and then measure it again. If it is still 18 ohms then it really needs to be replaced but at 18 ohms, I think that it would remove itself.
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i removed it from the board and it is giving me a reading of 17-18
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Then it looks like you have the answer to your problem which is to replace the resistor. This is a common resistor value and should be available at Radio Shack.
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ok...thanks!
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Looking at your picture it sure looked like an 18 Ohm resistor according to the bands. But the way some mark their devices it could mean anything.
You have a brown and gray bands which should be 18 ohms, the one you need should have brown, black, brown. or marked with 100 or 101.
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can i use this?
http://www.weisd.com/test/WEISD_TBL_view.php?editid1=NTE5W110
found it at frys
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I vote yes but would want a confirmation from another member. http://www.digikey.com/classic/documentredirector.aspx?doc=http://www.digikey.com%2fWeb%20Export%2fSupplier%20Content%2fRiedon_696%2fPDF%2friedon-an-wirewound-vs-film.pdf (http://www.digikey.com/classic/documentredirector.aspx?doc=http://www.digikey.com%2fWeb%20Export%2fSupplier%20Content%2fRiedon_696%2fPDF%2friedon-an-wirewound-vs-film.pdf)
Another idea is to shoot rainlover (coop mgr) a PM and see if he has an extra leftover and he could mail you one...
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The spacing between the bent leads will be 1 inch on that resistor. Body length is .88 inches
What is the spacing on the holes on the PCB?
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Sure, you can use that one if you want to. That is a ceramic resistor and since they can deal well with heat, it may get hot but should work just fine.
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it is the ony one I can find in the stores near me. If there is no bad effect to the board/controller, I will use it then. Thanks!
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it is the ony one I can find in the stores near me. If there is no bad effect to the board/controller, I will use it then. Thanks!
I recommend mounting the resistor at least 1/4" above the PCB to help dissipate heat better and not burn the board.
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I am using these Ceramic Cement Resistor 100 Ohm 5W
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I mounted the resistor closer to the edge of the board and away from the nearest part. It seems to be working fine and not as hot as the previous part.