I want to design a diode circuit

[Nickclark]

i want to design a diode circuit where the Vo vs. Vi looks like this:

Vi between -2 and 2 Vo = Vi

Vi between 2 and 4 Vo is a linear with slope 0.5
Vi between -2 and -4 Vo is a linear with slope 0.5

Vi>4 Vo=3
Vi<4 Vo=-3

how can i do this?

 

[mfb]

Just with diodes? Are you sure this is possible?

With a lot of transistors and resistors? That is possible, but it could look messy.

 

[Nickclark]

you can use diodes, voltage sources, and resistors.
i don't know how to get Vo=3 if Vi=4 and Vo=-3 if Vi=4 in one circuit!

 

[sophiecentaur]

This takes me back to generating arbitrary laws with 'piecewise linear' circuits using zener diodes and resistors. I googled the term and saw this link, which does the sort of thing I think you are after. (about half way through the slide show). Google the same term and you should get some other suggestions.
You'd have to work out the resistors for yourself but you should be able to solve the problem that way.

 

[Nickclark]

That's exactly what i was looking for! Thank you!
I solved it without zener, but used diode and a voltage source instead, hopefully it's correct!
Thanks again!