The Welwyn RC55Y looks like an interesting resistor, the specifications look good, and the price seems do-able. The price is, actually, about 2x the, now obsolete, IRC RC55-D price. I have used the IRC RC55-D for a long time and they never disappointed me
and at the given price level I did use them as my general-purpose-resistors, but at 2x, or more, times this price I need to consider getting 2 types of resistors (and I do not like that).Now the big question is; what to do next? First I need to know why the new IRC RC55LF-D is so much more expensive. Then, if I want to pay this price, I need to consider a second resistor for 'general-purpose', and what will that be?
More questions than answers for now.
P.s.
> First I need to know why the new IRC RC55LF-D is so much more expensive.
This question has been forwarded to Mouser (as this is my principal supplier).
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Easy because your cheap chinese DMM wuld mesure different than my cheap corean one.
But you do not have to do it...
The nice people at Mouser have answered my questions; the short answer is, most probably no change except that the 'LF' is RoHS compliant.
The long answer (or the contents of the email's is).
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Dear <Mouser>
To my surprise I see that the IRC RC55-D resistors are marked as ‘End of life’. As this was my ‘standard’ resistor I do need to select another ‘standard’ resistor. The first type that seems a reasonable replacement is the IRC RC55LF-D, the problem is the price 2x to 3x, and more, expensive.
My questions to you would be, why is the ‘LF’-product that more expensive, and what is the deference (between the ‘IRC RC55-D’ and the ‘IRC RC55LF-D’ products). I cannot get these answers from the web-site due to the fact that both products show the same datasheet.
Best regards,
Frans de Wit.
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Hello Frans de Wit
Thank you for your email. Can I check – are you referring to the whole series of RC55-D parts as in the following link or are there particular specifications that you require? We would cross reference individually for you in case one manufacturer has something more suitable and price competitive than another. What are the parts that you use regularly?
IRC RC55-D Metal Film Resistors - Through Hole | Mouser
The LF parts would be the new RoHS compliant parts and it’s more likely that the non RoHS compliant parts were bought at a much earlier date than the newer version and may have more expensive material to replace the lead.
If you can let us know which particular products you are interested in we can try to cross reference them for you.
With kind regards
<Mouser>
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Dear <Mouser>
> Can I check – are you referring to the whole series of RC55-D parts
Yes I am, currently I am using this resistor range as my standard ‘general-purpose’ resistor. My single source for these resistors is Mouser.
If the only difference between the RC55-D and the RC55LF-D is the RoHS compliancy then I do not understand why the price has been doubled, even tripled for some values.
Best regards,
Frans de Wit.
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Hello Frans
Quote: Q...
I have heard back from the technical team and they recommend the Vishay CMF range of resistors as per the following link:
http://www.mouser.com/ds/2/427/cmfind-111261.pdf
They did also comment on the pricing of the IRC RoHS and Non RoHS parts and say that the difference in materials used and the cost increase of raw materials over the last couple of years has added to the increase in cost of the actual parts.
If you need any further assistance at this stage, please let us know.
With kind regards
<Mouser>
Not a bad choice
in my opinion any of these (listed below) will be good choices. Select 25ppm or less, use 1% or less (except for filters, then use 0.1% (or less)). I'm not sure if there is a difference between the Welwyn and the IRC versions, the datasheet looks the same (even the picture of the device seems to be copied). So these are my recommendations, if you are going for an 'up-market' resistor. For now, I think I go with the Welwyn (the IRC is getting a bit too expensive for me (at Mouser anyway)).http://www.welwyn-tt.com/pdf/datasheet/RC.PDF
http://www.vishay.com/docs/31018/cmfind.pdf
http://www.irctt.com/file.aspx?product_id=168&file_type=datasheet
If you are on a budget (sort of
) you could go for Yageo MFPhttp://www.yageo.com/documents/recent/Leaded-R_MFP_2011.pdf
And then there is Beyschlag MMB (Joachim
) but I can not find a fitting datasheet and/or supplier
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Here is a selection of the through holes they make :
Vishay - Vishay Beyschlag - Vishay Brands
Vishay - Vishay Beyschlag - Vishay Brands
And here a direct link to the MBB type resistor (Not MMB ).
http://www.vishay.com/docs/28767/28767.pdf
http://www.vishay.com/docs/28766/28766.pdf
I think we now have a good selection of resistors. And that answers some other questions I did get at FrickleFest.
P.s. The booze is now completely gone, time for some new
(Not MMB ).http://www.vishay.com/docs/28767/28767.pdf
http://www.vishay.com/docs/28766/28766.pdf
I think we now have a good selection of resistors. And that answers some other questions I did get at FrickleFest.
P.s. The booze is now completely gone, time for some new
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What about this, is this a typo?RM 1% 0 R (ZOR-25-T-52-0R) YAGEO | SOS electronic
Zero-ohm-resistor, 1% of 0 (zero) what is that? If a zero ohm resistor dissipates a maximum of I*I*R = 0 Watt why the 25 Amp limit? And the connecting wires must they be super cooled? Anyway I never saw a zero-ohm-resistor.
One black belt, it is the karate-kid of resistors, or in other words, resistance is futile
http://en.wikipedia.org/wiki/Borg_(Star_Trek)http://www.soselectronic.com/a_info/resource/a/A10_rezis_siete/zor.pdf
I will wait for that option before I continue populating my new boards
Sorry I havent been here for a while, I will speed up