Saw Frequency doubler and Phase Shifter

[Magnus Danielson]

Hi there!

I have now provided the schematics for a simpler frequency doubler as well as
an equally simple phase shifter. Both work for sawtooth signal.

Also, I have provided a "Curcuit Theory of Operation" which gives a brief
description of how these works.

I really should redo the calculations on the resistor values, since I think I
may have gotten some of them wrong one way or another, but the general idea
should be correct and I can allways fix the little details at some later time.

Now, the phase shifter operates from -180 degrees to +180 degrees, or if you
so wishes, from 0 degrees to 360 degrees.

A side consequence of both these curcuits is that you have a PWM signal
available, good to know if you need one.

One should know that the resistors is intended to be scaled for -5V -> + 5V
sawtooth and +/- 15V of op-amp supply voltage (and thus assumed output swing).

Both these are a bit cheap-ish, so droping a bunch of trimmer setups on these
is required if you require better precission.

Cheers,
Magnus