Electronic forum or anyone know what I mean:

[Wizard]

By this:

First stage of circuit converts freq to voltage (higher f=higher volt). That's easy part.

Now that simply makes a chart of voltage curve, BUT I need to pull or lower Y of the curve of several spots along the X axis so curve becomes non-uniform via several resistor potimeters. Yes, all analog, no CPU or microcontroller please. This resulting output is used for other uses.

This is giving me hard time on that area with this section on design of circuits. I have easy time finding info on freq to voltage stuff but adjust the curve is not.

Help?

Cheers, Wizard

[TheLaw]

Re: Electronic forum or anyone know what I mean:

Shesh, I'd like to help you, but this is a bit over my head. I'll look for you though.

[b700029]

Re: Electronic forum or anyone know what I mean:

Put the frequency signal through one or more adjustable low/high-pass filters before converting to voltage.

[kikkoman]

Re: Electronic forum or anyone know what I mean:

can you elaborate a bit? post a sketch ?
you mean something like a notch filter but on the voltage side, right?

a filter on the input sounds easier than it is because the amplitude of the signal doesn't matter; you'd have to reliably attenuate it it below the signal threshold of the input. if you have harmonics, it gets really shitty.

what frequency range do you have in mind?

huh. this sounds tricky but i'm sure there's an easy way to pull it off.

[Wizard]

Re: Electronic forum or anyone know what I mean:

Not filtering not passband stuff.

Eg: frequency increases along X axis, voltage rises on Y axis, that's linear line.
But goal is to adjust the "dots" along the line into nonlinear line.

Rough example:

100Hz = 2V
500Hz = 3V
so on...

2000Hz = 10V
3000Hz = 15V

voltages would looks like

2V, 3V, 4V, ..... 15V linear.

But I wanted to adjust these like this by series of pots or different resistors networks to make this become non-linear and adjustable. If I have to do this in frequency instead of voltage, that would do fine.

2V, 2.5V, 3V, 5V, 5V, 6V, 6.2V 7V, 8V, 12V, 16V, 18V

Cheers, Wizard