DiyLightAnimation

Hardware => Lynx Express => Topic started by: jay9158 on October 01, 2015, 07:17:01 pm

Title: temperature check
Post by: jay9158 on October 01, 2015, 07:17:01 pm

How hot should the 2 15k resistors get under no load or standby condition. i am using 230v and they are very hot ???

Title: Re: temperature check
Post by: tbone321 on October 01, 2015, 07:41:29 pm

Did you make the required changes to the board under the transformer to allow the LE to run on 230V?

Title: Re: temperature check
Post by: jay9158 on October 02, 2015, 02:17:09 pm

yes all mods made

Title: Re: temperature check
Post by: tbone321 on October 03, 2015, 12:34:21 pm

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.

Title: Re: temperature check
Post by: jay9158 on October 03, 2015, 05:42:21 pm

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

Title: Re: temperature check
Post by: tbone321 on October 03, 2015, 06:10:49 pm

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.

Title: Re: temperature check
Post by: jay9158 on October 03, 2015, 10:55:06 pm

i will do in a few hours.

Title: Re: temperature check
Post by: jay9158 on October 04, 2015, 02:47:06 pm

hope these ok

Title: Re: temperature check
Post by: jay9158 on October 06, 2015, 01:55:09 pm

i cant find any issues my self but have a look and see if anyone else can

Title: Re: temperature check
Post by: jay9158 on October 07, 2015, 05:47:30 pm

is this any better

Title: Re: temperature check
Post by: jay9158 on October 07, 2015, 05:49:47 pm

and this one. this is the best pic i have, any ideas as to fault be much appreciated

Title: Re: temperature check
Post by: jay9158 on October 07, 2015, 06:39:50 pm

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

Title: Re: temperature check
Post by: n1ist on October 07, 2015, 08:56:08 pm

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

Title: Re: temperature check
Post by: jay9158 on October 08, 2015, 02:51:39 pm

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

Title: Re: temperature check
Post by: jay9158 on October 08, 2015, 03:06:02 pm

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

Title: Re: temperature check
Post by: jay9158 on October 08, 2015, 06:42:56 pm

i have found them in france! not bad price either and postage good, is this going to be the best way forward no other options ? change to 2 x 30KOhm 1W 5% resistors  just checking before i order dont want to get this wrong as need for halloween. and thanks all for the help much appreciated  :)