How can I find this component?  - Page 1
Forum section: electronics / beginners

author: gutabo34fr
author_rank: Newbie
timestamp: June 11, 2015, 03:18:04 am
content: Hello All,This is my first message on this board. Although I am an electrophysiologist,in silicoelectronics is very new for me. I am currently working at understanding how all this magic works.For a start, I guess some tear down and repairs are good.Getting to the point, my car stereo power/volume button is faulty.You will find attached some pictures of the thing.I now know that this an encoder but I haven't been able to shop a spare online. All the electronic components merchant websites have loads of encoders and I couldn't properly filter the results.Could you please give me a little help for this please?This is a ford factory stereo, the encoder switch comes back on its own when pushed and it turns indefinitely without *clics*.Many thanks

author: helius
author_rank: Super Contributor
timestamp: June 11, 2015, 03:42:47 am
content: You need to look closely for identifying numbers and marks, then search the catalogs of companies that make this type of part. Piher, Cherry, Alps, Alpha, Bourns...

author: ivan747
author_rank: Super Contributor
timestamp: June 11, 2015, 03:47:21 am
content: If you find any markings, try to photograph them, that can help to narrow down things.

author: gutabo34fr
author_rank: Newbie
timestamp: June 11, 2015, 04:27:04 am
content: Of course, sorry I forgot to mention that.You'll find new pictures attached.Looks like: MG, JPN (Japan I guess) and 2005.Thanks

author: free_electron
author_rank: Super Contributor
timestamp: June 11, 2015, 04:37:30 am
content: Matsushita (panasonic )but it may be hard to find the exact one. these are often custom made.i would carefully open it , flush it with IPA , apply some electrolube or contact spray and put it back together.

author: kwass
author_rank: Frequent Contributor
timestamp: June 11, 2015, 04:54:19 am
content: This looks to be an 11mm rotary encoder, a very common size. You could likely use anyone to replace it that's the same size, shaft type and mounting method. You don't really need to match the number of pulses per revolution and it certainly doens't matter if it has clicks or not. The worst thing that can happen is that it the direction of rotation is backwards to what you had before, but you can avoid that problem by carefully checking the one you have on a 'scope to see which pin makes the connection to the common first.

author: LukeW
author_rank: Frequent Contributor
timestamp: June 11, 2015, 05:38:51 am
content: You probably won't be able to get an exact match from the original manufacturer.Have a look at some rotary encoders on DigiKey etc, have a look at the datasheets, until you find one that has the same shape, actuator diameter, PCB footprint and A/B/Com pinout.http://www.bourns.com/data/global/pdfs/PEC12R.pdfhttp://www.digikey.com.au/product-detail/en/PEC12R-4220F-S0024/PEC12R-4220F-S0024-ND/4499653How close is that one to matching the footprint of yours?

author: gutabo34fr
author_rank: Newbie
timestamp: June 11, 2015, 06:52:07 am
content: Thanks for your replies.@ free_electronI kinda broke it when I desoldered it. I lack good equipment.@ kwass"checking the one you have on a 'scope to see which pin makes the connection to the common first."I guess 'scope is oscilloscope (not microscope) and "common" is the ground right?@ LukeWIn terms of spacing between the pins it looks good.According to the datasheet I am trying to determinate the part number.I need a few precision:- What are bushing? Do I need them?- Are "detents" the clicks I was referring to in the first post?- I am not sure how to measure the shaft length. According to the table at the bottom of the datasheet, it corresponds to the overall length of the encoder (referred as "L"). That would do 25mm in my case.

author: Deathwish
author_rank: Unknown
timestamp: June 11, 2015, 07:09:59 am
content: Make and model of the car stereo ?.

author: dmills
author_rank: Super Contributor
timestamp: June 11, 2015, 08:47:17 am
content: It looks broadly similar to a Bourns PEC11R series part (I have just specified these in a product), lots of options and Mouser has stock.Alps also make something similar, but usually without the threaded brushing.Try something like a PEC11R-4020F-S-24 or such, Datasheethttp://www.farnell.com/datasheets/1909741.pdftells you how to build a part number given shaft length and such.Detents refers to the number of 'clicks', and you want a reasonable number of pulses per rev (16 or 24 at a guess), The 'S' version has a push button like that one you have.Regards, Dan.

author: kwass
author_rank: Frequent Contributor
timestamp: June 11, 2015, 02:37:39 pm
content: [Quoteyes!QuoteIt might be, ground depends on the circuit that the encoder is used in, not the encoder itself.Common is almost certainly the middle terminal of the 3-pin side of the encoder. The left and right terminals make/break contact with the common as you turn the encoder. One contact will be made before the other one is as you turn it. The 2-pin side of the encoder is for the push button function. A connection is made between those 2 terminals when the encoder shaft button is pushed down.QuoteBushing, in this case, is the mounting method. The threaded part surrounding the encoder shaft.QuoteDetentes are for making the "clicks" and indicated when the contacts are made/broken as you turn the shaft. There is typically none, one or two detentes per make/break connection.QuoteThis is tricky, you need to look at the manufacturers drawing of the encoder to see how that's measured.

author: gutabo34fr
author_rank: Newbie
timestamp: June 11, 2015, 08:47:54 pm
content: Thank you all for your very useful replies.I am gonna go for a PEC11R-4-3-20-F-S-0012 reference.