Design Con 2015
Breaking News
Comments
Newest First | Oldest First | Threaded View
<<   <   Page 2 / 5   >   >>
Etmax
User Rank
Rookie
Re: Not just resistors
Etmax   2/26/2014 7:07:58 PM
NO RATINGS
Hi Max, I do a lot of design and prototype assembly for my customers and am forever buying in short strips of components.

Often I get parts that are not what's on the label and so I now check all parts received before they are loaded on the board.

Unmarked caps haven't bothered me too much because in general there are only 3-5 different values on a PCB so using a component tester is not a major drama.

Having to do this now for every resistor value tells me that I won't specify Yageo anymore.

Yes I agree lets start a campaign to get caps marked and boycott those that don't support our needs

Another point someone made was how do you ensure you will get marked parts if the partNo is unchanged. The answer is you can't, and I doubt this oversight will be supported by ISO9000.

Max The Magnificent
User Rank
Blogger
Re: What about surface mount capacitors?
Max The Magnificent   2/26/2014 5:37:10 PM
NO RATINGS
@Rick: Where do I sign the petition!?!?!

What are you talking about?  I thought you were going to organize the petition (I'm too busy selecting which Hawaiian shirts I'm going to wear at EE Live!)

Max The Magnificent
User Rank
Blogger
Re: What about surface mount capacitors?
Max The Magnificent   2/26/2014 5:37:09 PM
NO RATINGS
@Rick: Where do I sign the petition!?!?!

What are you talking about?  I thought you were going to organize the petition (I'm too busy selecting which Hawaiian shirts I'm going to wear at EE Live!)

Rcurl
User Rank
Rookie
Re: What about surface mount capacitors?
Rcurl   2/26/2014 5:34:01 PM
NO RATINGS
@Max: "I think we should start a campaign to persuade manufacturers to add markings to their surface mount capacitors!"

Where do I sign the petition!?!?!

Rcurl
User Rank
Rookie
Re: What about surface mount capacitors?
Rcurl   2/26/2014 5:26:04 PM
NO RATINGS
@Wnderer:"I've given this some thought. The very least they could do is color code them within a factor of ten."

Your comment made me realize that we've come full circle on this. If you're as old as me. you'll remember these from 60 years ago: http://www.tpub.com/neets/book2/32NE0180.GIF

zeeglen
User Rank
Blogger
Re: MOVs (and other unknown devices)
zeeglen   2/25/2014 2:48:47 PM
NO RATINGS
One product I ran into used MELF diodes with a single blue color band.  The circuit they were used in was very strange, appeared that it would draw excessive current.  Fortunately when studying an earlier revision of the product that used thru-hole the number 1N5305 was marked on the diodes, turned out to be not a true diode at all but a 2 mA current regulator made from a FET with gate and source tied together through an internal resistor.

SOT23 packages with their 2 or 3 letter codes are not quite as bad, there are several code-lookup sites online.  Where it does get tough is when the code is not listed on these sites.

antedeluvian
User Rank
Blogger
MOVs
antedeluvian   2/25/2014 11:55:18 AM
NO RATINGS
I think SMD MOVs have never had any marking on them. I have a product that uses a 5V5 and a 33V MOV and you cannot tell the difference. Of course you know what happened- they got interchanged. We got some very strange results reported from the test department of our sub.

The only way to test an MOV is to force it into clamping using a current limiting resistor- It is not a simple exercise, especially when you are using 1206 components since you first have to remove the part from the design- connect a resistor and then apply a voltage.

Even more concerning is the fact that if they used a 33V in place of a 5V, test would not normally detect it, but the product would be unprotected.

The production house could even place a capacitor there and we would be none the wiser.

It would be so much easier if they were marked!!!!

MeasurementBlues
User Rank
Blogger
Re: Resistor colors
MeasurementBlues   2/25/2014 8:26:48 AM
NO RATINGS
@zeeglen,

"those thru-hole resistors printed with text"

It's a conspiracy, probably started by Analog Devices and Analogic when they both made ADC, ADC, and PGA modules. They copied each other all the time. I know because I was once given the job of tracing out a schematic of one onf "Bernie's" modules when I worked at ADI right out of college. We copied them.

Rcurl
User Rank
Rookie
Re: Counterfeiting
Rcurl   2/25/2014 8:08:14 AM
NO RATINGS
@Dom Lodge: I wonder what future impact this may have on counterfeiting if it was to be applied to all components.  One fo the first things to check is whether the markings are correct / have been changed

Good point! Without markings we certainly lose a lot of traceability.

Rcurl
User Rank
Rookie
Re: Not just resistors
Rcurl   2/25/2014 8:05:55 AM
NO RATINGS
@Zeeglen: You CAN get SMT capacitors marked with value codes - 
http://www.vishay.com/doc?45028

You had me all excited for a minute there....until I looked on Digi-key. The only ones I can find listed are more than 10X what I had been paying for the same values!  It's hard to find them, since there's no parametric search option that I can find for markings.

Do you know of any available marked caps that won't break the bank?

<<   <   Page 2 / 5   >   >>


Top Comments of the Week
Flash Poll
Like Us on Facebook

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Life
Frankenstein's Fix, Teardowns, Sideshows, Design Contests, Reader Content & More
<b><a href=Betajet">

The Circle – The Future's Imperfect in the Present Tense
Betajet
5 comments
The Circle, a satirical, dystopian novel published in 2013 by San Francisco-based writer Dave Eggers, is about a large, very powerful technology company that combines aspects of Google, ...

Max Maxfield

Recommended Reads From the Engineer's Bookshelf
Max Maxfield
27 comments
I'm not sure if I read more than most folks or not, but I do I know that I spend quite a lot of time reading. I hate to be idle, so I always have a book or two somewhere about my person -- ...

Martin Rowe

Make This Engineering Museum a Reality
Martin Rowe
Post a comment
Vincent Valentine is a man on a mission. He wants to make the first house to ever have a telephone into a telephone museum. Without help, it may not happen.

Rich Quinnell

Making the Grade in Industrial Design
Rich Quinnell
16 comments
As every developer knows, there are the paper specifications for a product design, and then there are the real requirements. The paper specs are dry, bland, and rigidly numeric, making ...

Special Video Section
The LT8640 is a 42V, 5A synchronous step-down regulator ...
The LTC2000 high-speed DAC has low noise and excellent ...
How do you protect the load and ensure output continues to ...
General-purpose DACs have applications in instrumentation, ...
Linear Technology demonstrates its latest measurement ...
10:29
Demos from Maxim Integrated at Electronica 2014 show ...
Bosch CEO Stefan Finkbeiner shows off latest combo and ...
STMicroelectronics demoed this simple gesture control ...
Keysight shows you what signals lurk in real-time at 510MHz ...
TE Connectivity's clear-plastic, full-size model car shows ...
Why culture makes Linear Tech a winner.
Recently formed Architects of Modern Power consortium ...
Specially modified Corvette C7 Stingray responds to ex Indy ...
Avago’s ACPL-K30T is the first solid-state driver qualified ...
NXP launches its line of multi-gate, multifunction, ...
Doug Bailey, VP of marketing at Power Integrations, gives a ...
See how to ease software bring-up with DesignWare IP ...
DesignWare IP Prototyping Kits enable fast software ...
This video explores the LT3086, a new member of our LDO+ ...
In today’s modern electronic systems, the need for power ...