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Help Needed - Thomson 27LCDB03B not working
mattlumb:
I'm a bit late but, that's a wirewound resistor, Acrantophis. It may work, but its internal inductance may be too high to accurately sense the fast-changing switching current. The power supply may not be stable (whine/fizz) or may not regulate. A low inductance metal film resistor is the best choice. I don't know the size of the original but a 2512 SMD resistor might be alright - this one is 0.3R and should do:
http://uk.farnell.com/bourns/crm2512-fx-r300elf/resistor-2512-0r300-1-2w/dp/1865266
Fitting a 3R in parallel would trim the resistance closer to spec. if needed.
Alternatively you can piggy back a 0.56R and a 0.51R (in parallel):
http://uk.farnell.com/bourns/crm2512-fx-r510elf/resistor-2512-0r510-1-2w/dp/1865267 and
http://uk.farnell.com/panasonic/erj1trqfr56u/resistor-2512-1w-1-0r56/dp/1717955
Matt
micheldeman:
Sorry to interupt, the resistors of 68K and 0.27 ohm are conventional (through hole) ones.
The smd ones that I referred to, are other ones that I still need to find later on.
So I need a 2 watt 0.27 ohm conventional resistor.
You can see the one in question over here:
http://www.mijnalbum.nl/GroteFoto-KYJR7N7R.jpg
it's the green one.
thanks
Michael
Acrantophis:
Matt, I was intentionally steering clear of Farnell due to minimum order values but it looks like the information I gave was bad anyway, so thanx for highlighting this. :oops:
Apologies Michael, I wrongly assumed that you were after a surface mount item, my bad, these might be a more suitable option http://www.ebay.co.uk/itm/10pcs-Ceramic-Cement-Power-Resistor-5W-0-27-ohm-/160575692046?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item25630e9d0e
As you advise the 68K device measured OK I've not looked for that.
Regarding the SMD resistors you are looking to replace at some point, if you can find the relevant section on the schematics it will tell you whether they are 0603 or 0805 devices, see NOTES at the bottom left of each section. Schematics here - http://www.tv.quuq.org/forum/index.php?action=dlattach;topic=5757.0;attach=2959 these should be easy to obtain from RS or other sources
micheldeman:
Hi Acrantophis,
it's hard to find that 0.27 ohm 2 watt resistor. The link you gave directs to hong kong. Sounds strange that I have to go to the other side of the world to find a resistor. So I will keep that open for now and focus on the smd resistors first.
The ones are:
R6310 1206j10, I understood this means size 1206 and value 10ohm.
R6311 20k
R6327 1k
The sizes of these 2 I can't find on the schema, I only can see that they are a bit smaller than the R6310.
I checked an overview of smd sizes on the internet and I think they should be 0805 type.
Will go to RS in Nuneaton and see what they have.
BTW: the 2 watt resisitors are some kind of glued against the heat sink. It's some kind of compound but then hardened. How is this product called because I might need it later when I have to replace the 0.27 ohm 2 watt resistor? They probably need cooling.
Thanks again,
Michael
micheldeman:
I came just back from RS components and bought the following smd resistors:
for the R6310 1206j10, I bought item number 6934502 (thin film)
for the R6311 20k, I bought item number 6791077 (thick film)
for the R6327 1k, I bought item number 2230427 (thick film)
As I don't know about differences beteen type of resistors, would these resistors be ok to use?
BTW, I found this link:
http://www.wiltsgrove.co.uk/product-details.php?catid=0027&subid=1104&itemid=FR-2051
No idea whether this resistor will do as replacement for the 0.27 ohm 2 watt resistor. Will try to contact them.
thanks,
Michael
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