help with potentiometer

[tree98]

Hello to everyone on the forum!! I'm new here and to be honest don't have any real electronic's knowledge,but I do have an electronics problem What I have is a Bourns 3540s-762-502 res 5k ohm _+5% lin _+0.25% below all that it says 0604X.What i'm trying to accomplish requires the same size potentiometer,same shaft size,same everything but for every turn this one makes i need the new one to be the equivilant of 3 turns.I could change the gear to one thats 1/3 the size but i'm hoping i can just get a new potentiometer to do this and make it easier.

 

[shrtrnd]

I don't recognize the -762- reference, maybe this is a custom pot of some type?
The 3540S series are usually 10-turn pots. The 0604X reference is the date code,
2006 4th week of manufacture.
If I were you, I'd check the Bourns website, and start searching for what you need.
I doubt they make a 30-turn pot, but you might be able to find a 'calibrated scale dial'
that would gear you down to what you're trying to do.

 

[tree98]

Thanks for the help!! I did search the bourns website and I couldn't make heads or tails of the information on there you said it's probably a 10 turn pot,if thats the case i would actually need a 3.33 turn pot.I have a feeling one of those would not exist Could you explain to me what a calibrated scale dial is and how I could use it in this application?Once again thanks

 

[shrtrnd]

You said you don't have any electronics knowledge, so I'll do some of the leg-work for
you on this one (but it'll help if you do more of your own).
Check the Bourns potentiometers on the Newark Electronics website if you're having
difficulty navigating the Bourns website.
As I said, you may have a custom pot that I'm not familiar with.
The available pot similar (maybe) to the one you describe is now designated 3540S-1-502.
That's a 10-turn pot. I still don't know if that's what you have with the number you gave.
The Bourns H-490 series 30-Turn counting dial (Newark lists H-492-3, H493-3, H494-3
varants for color & with or without a brake).
Stock numbers 12F9670 thru 12F9672 (Newark)
Your thinking is backwards on this. (If I understand you correctly)
You have (maybe) a 10-turn pot, you want three turns for each actual revolution of the pot shaft.
If you put a 30-turn 'counting dial' (I call them calibrated scale dial), on a 10-Turn pot,
you get three turns of the dial for each turn of the actual pot shaft.
Is that what you're trying to do?
Check the part numbers I gave you, and see if that's what you're intending.

 

[shrtrnd]

I did a little more checking.
If you're wanting to go the other way, and example of a 3-Turn 5K pot is the
Bourns 830-11502 (but it's physical dimensions are different from the 3540S.
Bourns is not the only manufacturer of pots.
If you don't find what you want, somebody here will help you to narrow it down if you
post follow-up questions.
Good luck.

 

[tree98]

Sorry I didnt explain it correctly the first time.What i need to do is have the "pot" get to where its going in almost exactly 1/3 the movement.So it would need to send the same" information" to the display as the 10 turn but in 3.33 turns,is that even possible?I think the bourns "pot" i have might be proprietary to the manufacturer of the equipment i'm trying to modify,that would explain why you can't find it's part number right?

 

[tree98]

shrtrnd,I looked at the counting dials on newark's site.I don't think that would work because the "pot" is gear driven off of a shaft.It looks like the counting dials might be used more as a hand operated control??Besides I need to go the other way,it would be like a counting dial that turned the "pot" 3.33 turns for every turn of the dial.

 

[shrtrnd]

OK. If the pot shaft is tied to a gear-driven actuator, the 'turns counting' dial is out.
Can you use the 3-turn Bourns 830-11502? If not try Googleing other 3-Turn pots from other manufacturers (Clarostat, Vishay, BI, or others).
I'm assuming this is some industrial application, like a position locator for a valve actuator.
Bourns makes a 3-Turn 5K pot, so others probably do also. You just need to find one that fits your enclosure.
Somebody here can probably give you better help, if you tell us your make and model
of what you're trying to modify.
As a last resort, I posted the name and address of a manufacturer in the mid-West
that builds custom pots. If I dig that up, I'll post it here later.

 

[shrtrnd]

The place I use to build custom potentiometers (they do have their own line of pots,
one of which my already fit your needs):
Maurey Instrument Corp 5959 W. 115the St Alsip, IL 60803