Potentiometer 4K, balance, 1/4 turn

[luis9191]

Hi everybody!

This regulates the balance between an electric-organ's 2 keyboards, say upper keyboard vs lower keyboard.

I haven't found anything like that at semiconductor-stores (I live in Mexico). https://1drv.ms/1d6Oa1J

I'd appreciate your oppinions. I'm open to any suppliers or ideas.

 

[KeepItSimpleStupid]

I haven't a clue. Do you have a schematic? All I see is two elements on the edge which would be measureable.

The center elements don't go any where. Something is missing from my understanding as to how it's supposed to work. 4K isn't common.

The only off the wall comment is a digipot or a motorized pot as a possible replacement or a cadaver unit.

Maybe?: **broken link removed**
4k7 is 4.7K or 4700 ohms.

You might need to figure out if they are log or linear. A part(s) seems to be missing.

 

[luis9191]

I haven't a clue. Do you have a schematic? All I see is two elements on the edge which would be measureable.

(...) are log or linear. A part(s) seems to be missing.

oh yeah you're right, the knob is "missing". I removed it so you could see what's going on inthere. I don't quite have an official diagram so I drew this 4 u... Attached img. Think of the orange parts like the conector on the knob

I saw the datasheet of your proposal... it doesn't sound that bad u know, man It rotates 300º, 1/2 turn more and 10 times more expensive than I thought, hehe nevermind. How did u find it???


PS
Congrats on your "Most Helpful Member" badge, you certainly deserve it and more

 

[KeepItSimpleStupid]

I know the result was in the first search I did., but I don't remember the search terms. I get

How did u find it???

a lot.

See if you can determine the LOG/Linear relationship. Get the resistances of the 2 segments to the terminals as shown and at 1/4 turn. Just use an ohmmeter.

Volume is a LOG relationship.

Your not out of the woods yet. See: http://www.resistorguide.com/potentiometer-taper/

These http://www.alps.com/prod/info/E/HTM...otentiometers/RotaryPotentiometers_list1.html are probably one of the better manufacturers on the planet. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CB8QFjAA&url=http://www.alps.com/prod/info/E/PDF/Potentiometer/TAPER.PDF&ei=hRhtVY2DJ4vutQXi04GADw&usg=AFQjCNGKJgmq333tv5cvb-CclNP7H7G98A&sig2=bWsTjpnKmjjUsw-M6rcEOQ&bvm=bv.94455598,d.b2w

You might need this **broken link removed** instead.

Some ALPS pots: **broken link removed** One is significantly more expensive, like $50 USD for a 5Kx2 LOG taper.

 

[luis9191]

Holy mother! It's a huge world of pots! Unfortunately I haven't found one with 1/4 cicle/turn.

It seems that one of my local suppliers might get what I need, but still waiting. Do you think the old one can be rebuilt?

 

[Mosaic]

Pots inline with the audio signal have to be good quality.
A digital pot can be an alternative..but you'd have to understand what you're doing.
https://www.maximintegrated.com/en/app-notes/index.mvp/id/1828

 

[dr pepper]

Allthough it might not be a pot specially made for that keyboard it looks like its one made for keyboards and sound equipment.
Theres a remote possibility you'd be able to find another pot similar and transplant some of the bits to make one good one.

 

[luis9191]

Allthough it might not be a pot specially made for that keyboard it looks like its one made for keyboards and sound equipment.
Theres a remote possibility you'd be able to find another pot similar and transplant some of the bits to make one good one.

Yeah... that's good idea, what I did indeed. Didn't quite fixed it, but at least is working.

Tnx guys!!!

 

[Tony Stewart]

A ganged linear or rotary pot using opposite ends for input and centre common will work with other ends to gnd.
4k to 10k shud work, but must be linear, not log since linear opposing taper needed.

 

[dr pepper]

Excellent, porbably the best you can get a partial fix.