Where to buy rubbers?

Thread Starter

wayneh

Joined Sep 9, 2010
17,495
Now that I have your attention... :D

I'm replacing a couple of damper diodes in a TV soon. (rest of the story) The diodes are installed with a rubbery sleeve around them. The diode package is plastic - no metal tab - so I'm not real sure what the function of the sleeves is, what they are called, or how to find new ones.
 

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mcgyvr

Joined Oct 15, 2009
5,394
Its just shrink tubing..

I wouldn't be surprised if when the Chinese copied that board from someone else the original designer did not have isolated diodes and used that for isolation but the Chinese bought the plastic package and just kept the tubing there not knowing any better.
 

Thread Starter

wayneh

Joined Sep 9, 2010
17,495
If it's heat shrink, I'm a little surprised it hasn't shrunk more. The diode failed to low ohms, so I'd guess it got pretty hot. The plastic was a bit difficult to separate from the body of the diode but otherwise didn't seem "tight" or distorted.

Since these diodes are rated to 1700V, could the sleeve be there to prevent arcing from the diode package to the heat sink behind it?

I'm wondering if some of that white pad thermal material, between the front bracket and the rear heat sink, might be a better fix.

FWIW, this ballast was built by Rubycon, a Japanese company.
 

tubeguy

Joined Nov 3, 2012
1,157
I go along with your extra insulation idea. That stuff might be some silicon type material which could withstand some heat without distorting. The thermal pads sound like a great idea. Maybe check voltage rating and use more layers if needed.

Edit: apprentice beat me :)
 

Thread Starter

wayneh

Joined Sep 9, 2010
17,495
Ooh, I think you're right. Thanks so much. I never would have found this or this on my own, but that looks just right. Now I just gotta find some.
 
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