Anyone recognize the brand on this potentiometer? - Page 1
Forum section: electronics / general

author: XOIIO
author_rank: Super Contributor
timestamp: June 21, 2021, 03:32:44 am
content: Working on repurposing a volume control dial, and found an interesting (what I think is a ) dual potentiometer, however A103 is the only marking, aside from an embossed logo that I don't recognize. Figured I'd see if anyone here recognizes it. Had a look at a couple lists but couldn't find much. Hoping to find a datasheet with a pinout guide as it seems a little odd trying to meter it out. (that or I partially cooked it)

author: ataradov
author_rank: Super Contributor
timestamp: June 21, 2021, 04:24:38 am
content: A103 is a 10kOhm logarithmic potentiometer (common in audio applications).I don't know manufacturer, but there are a lot of potentiometers in this type of package. I think they all have the same pinout, it should be easy to find and verify with the board. If I remember correctly it is some non-obvious pin assignment.Here is the pinout most of those 6 pin audio pots use:

author: XOIIO
author_rank: Super Contributor
timestamp: June 21, 2021, 04:39:56 am
content: Quote from: ataradov on June 21, 2021, 04:24:38 amIt did seem like that when I got it wired up and working with an arduino, it's also behaving a little oddly, maybe because of the pins I'm connected to, but analog reading it, it essentially goes to the max value of 1023, then starts to drop off again, which means it's a no go for use, I guess because it's not a strictly linear one.Guess I'll have to make and 3d print a mount for a panel mount unit as well as finding one that has the right shaped end to work. Sure there are volume knobs on amazon with more features but they aren't free, and they also are really chunky in comparison to this one.edit: Ah, so I did find the correct three pins to hook into then, good to know.

author: ataradov
author_rank: Super Contributor
timestamp: June 21, 2021, 04:41:29 am
content: It is not linear (logarithmic), but it should be monotonic.

author: XOIIO
author_rank: Super Contributor
timestamp: June 21, 2021, 05:42:54 am
content: Quote from: ataradov on June 21, 2021, 04:41:29 amit is, it goes marginally over 10k checking with a meter, but for some reason the arduino reading it acts oddly.I found another post with odd behavior, though not matching mine, and I guess you can map out the potentiometer positions, but finding/buying a linear one sounds like it would be less finnicky, as I'm still not sure why it's dropping down after the maximum value. I guess due to how the code is written to read it, but that still shouldn't go negative.Honestly I do like the idea of finer control at the top and bottom end, but not sure off hand how to fix this issue.

author: ataradov
author_rank: Super Contributor
timestamp: June 21, 2021, 05:57:40 am
content: The extremes may be dodgy on any potentiometer, since wipers may interact with attachment points for the tracks. It would not be a long zone, but at the exact dead end, the value may not be very consistent.

author: XOIIO
author_rank: Super Contributor
timestamp: June 21, 2021, 06:47:11 am
content: Quote from: ataradov on June 21, 2021, 05:57:40 amUnfortunately it happens with about 1/4 turn left, so a decently long chunk.

author: ataradov
author_rank: Super Contributor
timestamp: June 21, 2021, 07:34:36 am
content: Then it may be damaged or dirty. It should not behave this way.

author: XOIIO
author_rank: Super Contributor
timestamp: June 21, 2021, 07:40:03 am
content: Ok, so it seems to be a two part issue, one is that the analog inputs on that one board I have seem a little screwed up, but secondly for some reason, the arduino script for volume control ignores the last 1/4, I think because they have it map the 1023 values to only 101 positions, I'm going to try increasing that to see if that does it.But yeah, trying on another board, no issue at all with it going into the negative.

author: XOIIO
author_rank: Super Contributor
timestamp: June 21, 2021, 07:45:30 am
content: Hmm, no, even just spitting out the raw analog value, the last 1/4 turn or above 6.6k ohms it isn't usable for some reason. HmmEdit: interestingly same brand on this potentiometer, I guess edifier sticks with their supplier lol. this one is a conventional one however.edit: actually it's probably logarithmic as well then

author: XOIIO
author_rank: Super Contributor
timestamp: June 22, 2021, 05:56:19 pm
content: Alright, figured it out after trying a 1k pot, turns out that the DIO pins are only running at 3.3v, however I had the potentiometer connected to the 5v output on the seedstudio xiao, that's why it was maxing out with so much travel left.