curve fitting

[audioguru]

How do u do this? what circuit would convert a linear pot to a square law resistance?

I mentioned three different ways to do it. Designing the circuit would require you to learn electronics and would be too complicated for it to just replace a simple pot.

Go to a guitar-effects forum and see what they have done.

 

[walters]

what 3 ways list them please?

 

[audioguru]

REPEAT:
1) I designed a slowly dimming and brightening LED circuit that has a square-law. Its input is linear.
2) Maybe an audio expander circuit could also be used.
3) Maybe a multiplier IC could be used.

 

[walters]

how do u get 315 degrees rotation of resistance in a 130 degree rotation?

I need to compress 315 rotations of resistance in a 130 degrees of rotation

How do i do this?

 

[akg]

how do u get 315 degrees rotation of resistance in a 130 degree rotation?

I need to compress 315 rotations of resistance in a 130 degrees of rotation

How do i do this?

:? :shock:

 

[Styx]

gearbox

 

[audioguru]

Sometimes I am passing another car on a two-lane road, and find a big truck coming at me. The floor of my car doesn't bend enough for me to push the throttle any more than only about 90 degrees.
Do you think adding a gearbox to the throttle pedal will allow my car to have more power??? :wink:

When I was a little kid I thought my father was very strong to push that throttle pedal hard enough to push the heavy car up hills. :lol:

 

[audioguru]

Walters could use pulleys on his wah wah pedal to gear-down its rotation, like the pulleys on his Leslie speaker.

I wonder how he is able to rotate his foot 330 degrees. Maybe he jumps on the pedal.

 

[mstechca]

how do u get 315 degrees rotation of resistance in a 130 degree rotation?

Walters, Go back to school. When you are done, you will find out that resistance is measured in ohms, not degrees.

I need to compress 315 rotations of resistance in a 130 degrees of rotation

good luck.

and another thing. isn't 315 bigger than 130?
the only way I can see it happening is to make the 315 degree rotation go back-and forth 2 and some odd times. then you can fit it into a 130 degree rotation. As for the resistance coming in, I can't really help you there.

What is it you want to rotate?

 

[Styx]

Sometimes I am passing another car on a two-lane road, and find a big truck coming at me. The floor of my car doesn't bend enough for me to push the throttle any more than only about 90 degrees.
Do you think adding a gearbox to the throttle pedal will allow my car to have more power??? :wink:

When I was a little kid I thought my father was very strong to push that throttle pedal hard enough to push the heavy car up hills. :lol:

Ok a "gearbox" wasn't the right description (was late when I posted), but two cogs of different ratio's would give the desired effect

 

[walters]

No the wah wah pedal only goes back and forth 130degrees of resistance rotation of the POT. I want to get 310 degrees of resistance rotation in a 130 degree "Throw"

310 degree of resistance=100K

130 degrees of resistance= of a 100k is only like 1/4 of it

So i need to compress 310 degrees of resistance down to 130 degrees of resistance of rotation

Becaues the wah pedal is limit of moving the pot shaft it only move it 130 degrees not the whole 310 degrees so i need to change the resistance pot shaft degree rotations

 

[audioguru]

Use a 250k 310 degrees pot. With only 130 degrees of shaft rotation its resistance will change about 105k and it will sound the same as a 100k 130 degrees pot.

 

[Nigel Goodwin]

A couple of points!

1) Normal pot rotation is 270 degrees.

2) Wah pedals use a rack and pinion system, with the pinion on the pot and the rack (which is slightly curved) pushed down by the pedal, this gives 270 degrees of rotation from a rocking pedal motion.

It's not rocket science!, it's been done essentially the same way for something like 40 years!.