Components with very poor documentation - Page 1
Forum section: electronics / beginners

author: fubar.gr
author_rank: Unknown
timestamp: August 22, 2016, 10:07:00 am
content: I hate products with nonexistent documentationTake this pushbutton for example:http://en.ninigi.com/product/ninigi/microswitch/tact-24n-f-igNo pinout diagram, no PCB dimensions, no info for the led (voltage drop and max current).How the heck am I supposed to integrate this into one of my projects?

author: LA7SJA
author_rank: Regular Contributor
timestamp: August 22, 2016, 11:02:55 am
content: Rant mode or question mode?Johan-Fredrik

author: Simon
author_rank: Unknown
timestamp: August 22, 2016, 11:34:08 am
content: what do you expect at those prices ? You get what you pay for.

author: b_force
author_rank: Super Contributor
timestamp: August 22, 2016, 12:02:11 pm
content: Well, to be honest, you see it even with the bigger well known companies.Some products have a very minimal description in their datasheets.Not to mention about how some people really make a mess with formulas, symbols and quantities.Sometimes so bad, that it takes a lot of time and frustration to figure out they're simply just talking about a simple Force in (N) or something.I guess that they don't really realize that an article is as good as it is written.Some people really just write a bug maze of struggles.

author: wraper
author_rank: Unknown
timestamp: August 22, 2016, 12:20:10 pm
content: This is some Chinese junk sold by TME undeir their Ninigi brand. To be fair, Multicomp branded parts from farnell often have datasheets of about the same quality.

author: Zero999
author_rank: Super Contributor
timestamp: August 22, 2016, 12:33:17 pm
content: Quote from: Simon on August 22, 2016, 11:34:08 amI'm unfamiliar with the currency on the site linked to by the original. Set in UK mode it says 0.9511GBP per unit, which doesn't seem cheap to me. Price isn't always a good indicator of quality though, just look at some of the cheap shit flogged by Maplin, for high prices, with no data and when you ask, customer service a question, all you get is "the product doesn't support that." which really means Maplin don't support their customers and the sales reps are retards.

author: Jeroen3
author_rank: Super Contributor
timestamp: August 22, 2016, 12:59:39 pm
content: Here you go.https://www.sparkfun.com/products/10440

author: Mechatrommer
author_rank: Super Contributor
timestamp: August 22, 2016, 01:01:24 pm
content: Quote from: fubar.gr on August 22, 2016, 10:07:00 amluckily dimension is provided, thats the first ballpark figure, if its right, what about buying it and get it in hand and then do 2 things on pins...1) continuity test2) diode testand then make pcb footprint to suit?

author: LA7SJA
author_rank: Regular Contributor
timestamp: August 22, 2016, 03:27:53 pm
content: If you use EAGLE:https://github.com/EagleWorks/eagle/tree/master/lbrJohan-Fredrik

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 22, 2016, 05:24:48 pm
content: Or when they do provide measurements, they don't apply the actual tolerances the parts have, so for example the alignment pegs of a connector have overlapping tolerances plus overly gross positional tolerances. Combined, it means a "correct" (guaranteed to fit the part, as specified in the drawing) footprint is useless -- the alignment holes have to be made so large that the part can be placed in either direction (the alignment pegs are nominally mismatched, so the part can't be inserted backwards), and over such a loose range of angles and positions that the pins can be completely misaligned.That's fairly uncommon though, except for the simpler kinds of parts that don't have many pins to misalign (like a coin cell holder). More often, the pins and component body are underspecified, so that an IPC compliant footprint cannot be calculated from the drawing.Inductors do that a lot. They come in literally a thousand package styles. Rather than specify the mechanical dimensions of the part, they'll recommend a footprint. Which leaves you with no clue if the footprints are any good or not.SFP (gigabit fiber interface modules) are terrible at this; the open spec does not specify component pin/lead dimensions/locations. Rather, the PCB footprint is defined, and, I guess the manufacturers have to design their products to fit the footprint. It's a backwards process, and we design engineers have no say in the result...Tim