Behringer potentiometer

[Demon]

A neat slide dual 10K potentiometer on AliExpress.



If you thought the 2 pins on the far left were the wipers, you'd make the coolest short circuit that can fry lots of gizmos. The wipers are on the right; they don't have a pin lined up with them on the far left.

Fortunately I tested each circuit as I was soldering them. Of course this pot was the last component I installed on the board. So now I have to scratch out some traces, and jump with wires.

Teach me right. (heavy sigh)

[Demon]

Heads up to the next guy that looks at these taper B 10K pots.

They are not completely straight linear, they have a slight curve at the 25% and 75% curve.

They are between the taper B3 and B4 on page 4:

https://www.bourns.com/docs/Product-Datasheets/PTL.pdf


These are NOT taper B1. They sure are smooth though.

[Ioannis]

Why would one need such a curve?

Ioannis

[Demon]

Audio mixers use them. Something about how the human ear works.

[Ioannis]

Any audio volume control will use logarithmic curve. Any tone control and balance uses linear as far as I know.

A mixer should also use log curve since it controls volume.

Ioannis

[Demon]

I don't know.

I bought a bunch of those Behringers thinking linear meant linear.

Apparently I was wrong. Sometimes it means "nearly" linear.

[Ioannis]

Is it a serious problem for your project? If yes, maybe you can calibrate it with software.

Ioannis

[Demon]

It is. People expect engine rpm to rise with throttle input.

I could, but I shouldn't have to. I'm waiting for a reply from bourns on an ordinary linear slide pot.

[Ioannis]

I agree. Hope you resolve this.

Ioannis

[Demon]

I agree. Hope you resolve this.

Ioannis

You inspired me to figure this out. My goal with this pot is to simulate the flaps lever in a Cessna 152 in MSFS 2020:




I added a frame around the slide pot with an edge on top at both ends, and indentations on both sides.

The skate just slides onto the shaft, with tiny "skiis" under to slide 1mm above the pot surface (the dust cover curls up as the shaft moves up and down, this causes friction under the skate if it's not elevated).

The arms on both sides have a bump that fits just right in the indentations.




This was made with PLA, but it'll most likely be ABS or PETG in final form. I'll just add a dab of lithium grease on both sides once I find out what lubricants I can safely add on those plastics.

I'm happy cause this will permit me to use the 100 or so I bought from AliExpress, and I get EXACTLY the feel I wanted on the device. I get 4 detents, but can still stop anywhere in between just like in-game.

(the action is super smooth, I have problems in the video cause I'm holding my phone, and the PCB slides on the paper so I have to push downwards with unusual effort)

[Ioannis]

Looks very nice!

And, besides the lubricant, you can "adjust" the needed force either on the dents shape or the "spring" angle/depth.

Very good idea.

Ioannis