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Author Topic: temperature check  (Read 2713 times)

Offline jay9158

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temperature check
« on: October 01, 2015, »
How hot should the 2 15k resistors get under no load or standby condition. i am using 230v and they are very hot ???
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Offline tbone321

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Re: temperature check
« Reply #1 on: October 01, 2015, »
Did you make the required changes to the board under the transformer to allow the LE to run on 230V?
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Offline jay9158

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Re: temperature check
« Reply #2 on: October 02, 2015, »
yes all mods made
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Offline tbone321

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Re: temperature check
« Reply #3 on: October 03, 2015, »
They should not get too hot.  You may want to take some pictures of the front and back of the board and post them here so we can take a look and see of something is wrong.
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If at first you don't succeed,
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Offline jay9158

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Re: temperature check
« Reply #4 on: October 03, 2015, »
TO hot to touch after 35 seconds but board tests out ok and seems to work otherwise. but at this temp they not gonna last.
2 links cut one added and 16 resistors changed
i have 2 230v boards with same problem and 1 110v board not problems
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Offline tbone321

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Re: temperature check
« Reply #5 on: October 03, 2015, »
It looks like something was not done correctly.  As suggested before, post a close-up picture of the front and back of the board so we can see what was done and what the possible issues are.
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If at first you don't succeed,
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Offline jay9158

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Re: temperature check
« Reply #6 on: October 03, 2015, »
i will do in a few hours.
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Offline jay9158

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Re: temperature check
« Reply #7 on: October 04, 2015, »
hope these ok
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Offline jay9158

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Re: temperature check
« Reply #8 on: October 06, 2015, »
i cant find any issues my self but have a look and see if anyone else can
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Offline jay9158

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Re: temperature check
« Reply #9 on: October 07, 2015, »
is this any better
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Offline jay9158

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Re: temperature check
« Reply #10 on: October 07, 2015, »
and this one. this is the best pic i have, any ideas as to fault be much appreciated
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Offline jay9158

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Re: temperature check
« Reply #11 on: October 07, 2015, »
i have double and triple checked the boards and just can not find a fault the 2 resistors get to hot to touch and not sure what to do now. any help or ideas welcome
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Offline n1ist

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Re: temperature check
« Reply #12 on: October 07, 2015, »
Doesn't surprise me.  At 120V, the two resistors dissipate 0.24W each.  At 240V, they dissipate 0.96W each.  That's much hotter, and honestly, pretty close to their 1W rating. 

When running on 240V, I would replace the two 15K 1W resistors with two 30K 1W resistors, Mouser part 294-30K-RC.  They will dissipate 0.48W then; a much better margin.

/mike
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Offline jay9158

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Re: temperature check
« Reply #13 on: October 08, 2015, »
that sounds like a plan. so there is no fault as such just they running hot due to the 230v and designed for 110v....many thanks i give it a go
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Offline jay9158

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Re: temperature check
« Reply #14 on: October 08, 2015, »
hi i need to get from rs components as mouser in the uk charge a £12 just for postage and i only need 4 resistors. cant seem to find that spec anywere other than hong kong but smallest order 200 of them arrgggghhh
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