6 pin potentiometer wiring? - Page 1
Forum section: electronics / beginners

author: shane_95
author_rank: Regular Contributor
timestamp: July 06, 2012, 11:51:48 am
content: I got a 6 pin potentiometer out of a Logitech subwoofer. Is there a way to wire it up to LED? If there is, how?

author: vk6zgo
author_rank: Super Contributor
timestamp: July 06, 2012, 12:00:20 pm
content: Your question is quite confusing.You really need to post a nice clear photo of the pot.There are a lot of different types of LEDS,from the normal ones which we use for indicator lights on Electronic equipment,to the high powerones used for lighting.From your previous postings,I think you mean the latter types.In that case,I would say that the current handling ability of ordinary pots of this kind won't be enough.In other words,it will get hot,& fail.

author: Simon
author_rank: Unknown
timestamp: July 06, 2012, 12:18:11 pm
content: I would strongly suggest Shane you start reading up on your theory. You obviously are passionate about electronics but you have been asking a lot of questions have don't have many details and seem more like whims than actual project ideas. Start out with a specific project and work out how to achieve it, even if it's just making circuits using the diagrams in the datasheet for IC's. If you have an end aim it will be easier for you to ask questions and for others to answer them.

author: vk6zgo
author_rank: Super Contributor
timestamp: July 06, 2012, 12:35:02 pm
content: What Simon said!

author: 6502nop
author_rank: Regular Contributor
timestamp: July 07, 2012, 02:38:39 am
content: Ditto, but...How many good tutorials have you run into that cover pots like this?Now, then... {ahem}...QuoteWhat you've probably got is a Dual potentiometer for stereo. They are "ganged" together so that each pot is moved at the same time for Left/Right control. The best way to be sure is to whip out your ohmmeter (you do have one, I hope?) and test the outer terminals of the two rows. This should give you your pot's value, which should match the code stamped on the body of the pot. The "wiper" is usually the center terminal. See attached PNG.I said "probably" above, because of a few things:- Audio pots usually have what's known as a "loudness tap", and you should therefore see four pins per channel, or eight total.- Subwoofers are usually monophonic, so what's a stereo pot doing in there? My guess would be it's pulling the bass signal from both channels and filtering them into one.- This could be a digital encoder, which tells the control IC of the Sub to do things. If this is the case, a picture is certainly needed.Lastly, to echo what the others are saying: In my day, there was no Google. No Internet. No computers, for that matter! No local guru to go to. If I wanted to know something, I hit the library or corner Rat Shack to brush up on my knowledge. It took a while, but I figured things out quickly enough. Nowadays, what used to take meweeksto get (datasheets, cross references, etc.), can now be had in a matter of seconds, thrown on a little reader tablet (Kindle), and sitting next to me as I assemble the circuit. Frickin'amazing! I know you're not asking how to build a Saturn-V or "Kisty-core" A-bomb (I can help you with those, BTW), but for crying out loud, could you at least make aneffortto do a Google search or two?nopGoogle "6502+NOP" for some early programming...Dewey decimal = 001.6x for computers and 621.x for electronics.Kisty core secret ingredient = Scotch (cello) tape. No, I'm not kidding.

author: Unknown
author_rank: Unknown
timestamp: July 07, 2012, 01:19:44 pm
content: Quote from: 6502nop on July 07, 2012, 02:38:39 amhttp://tangentsoft.net/audio/pancomp.htmlIt wouldn't surprise me if it was also covered in the Art of Electronics.

author: 6502nop
author_rank: Regular Contributor
timestamp: July 07, 2012, 09:56:22 pm
content: That link, like my last post, was more of an "overview", rather than a tutorial.Overview = what it is/does/looks like.Tutorial = why the @#$% any of ^that matters.It's like the Make series with Colin (?). He does a good job telling you what these componentsare, but very little on how they should beused. I also found it surprising that an audio site explained the different tapering of pots, but failed to mention the "loudness tap", as I did.The reason, I feel, that EEVblog has rocketed up the charts is that Dave goes the extra mile - er, kilometer - to explain thewhys of things.Whyyou should buy a good meter (kabang!).Whyyou should design ground/power planes a certain way.Whyyou shouldn't call Microchip engineers "dickheads".I also realized we didn't answer the main question of how to wire a pot to an LED. That's a loaded question, as we don't know:- Which LED(s)?- What's the power source/driver?- Why do you need a pot? PWM is the preferred method nowadays.- What, exactly, is shane_95 building?nop

author: Unknown
author_rank: Unknown
timestamp: July 07, 2012, 10:16:30 pm
content: I think most of this is beyond the scope of a mere tutorial, and requires some actual understanding of basic electronics. The step from 'a potmeter is a variable resistive divider' to 'how to regulate volume/light intensity' is not something I expect to be covered in a tutorial. It's hard to explain what a pot does in an audio (or LED) circuit without knowing about voltage dividers, source impedance and opamps. A general purpose electronics book aimed at beginners like Practical Electronics for Inventors would probably be the best place to start.The simplest solution of employing a ~10k pot to regulate LED current would probably be to connect the wiper to the base of a transistor configured as a current source. That or driving some dedicated PWM-based LED driver IC (more expensive, much more efficient). Both require some understanding of electronics beyond 'paint by the numbers'.

author: 6502nop
author_rank: Regular Contributor
timestamp: July 07, 2012, 11:02:09 pm
content: I'm wholeheartedly in agreement with you.The problem I'm seeing is that novices are going from the "grab an Arduino kit and program a chip" to having to sit down to learn what all the things you attach to the kit actually do. And it's something theydon'tdo, or wantsomeone elseto do for them.There is no substitute for a good solid fundamental understanding ofbasicelectronics, but as all of us who have it knows that ittakes time and effortto learn. It just seems to me that today's "There's an App for that" generation just doesn't want tosit down and learnsomething for themselves.Which leaves folks like us to try and explain, succinctly, a concept that took us weeks to master, and hand it to them in a paragraph or two. Thus, I like to give an overview first, then get into specifics if the OP still doesn't get it.nopPaint by the numbers? We used to call it "Eddy Electron" or "Randy Kilowatt".

author: G7PSK
author_rank: Super Contributor
timestamp: July 08, 2012, 10:23:38 am
content: The best thing that you can do Shane is get you multimeter set it to the ohms range and connect it to the pot. that you have and see what happens to the resistance as you turn the spindle on it, then try another pin on it and do the same, go through all the pin combinations that you can think of until you get a feel for how the unit behaves. Try to map in your head what is happening inside the pot and also draw it on paper and write you findings regarding the resistance relative to each pin down as well.

author: Unknown
author_rank: Unknown
timestamp: July 09, 2012, 07:36:50 am
content: Quote from: vk6zgo on July 06, 2012, 12:35:02 pmWasn't the correct answer, "it's usual to connect two of the pins to the same place and the other four to different places"?