BJ's 4046 oscillator

[BJ]

> Magnus Danielson wrote:
>  >>
>  >> Hi!
>  >>
>  >> It just truck me that there is more to BJs 4046 oscillator.
>  >>
>  >> >From the two buffer op-amps comes two waveforms that look like this
>  >>
>  >> 0 V -   ---   ---   ---   ---
>  >> \  |  \  |  \  |  \  |
>  >> \ |   \ |   \ |   \ |
>  >> \|    \|    \|    \|
>  >>
>  >> 0V   ---   ---   ---   ---   -
>  >> |  \  |  \  |  \  |  \  |
>  >> |   \ |   \ |   \ |   \ |
>  >> \|    \|    \|    \|    \|
>  >>
>  >> Adding them creates a saw, but subtracting them and you got yourself a
>  >> triangle. Using the saw+square trick you can have a sawtooth of the
>  >> same frequency as the triangle, and they are in phase. A deglitching
>  >> is assumed ofcourse.
>  >>
>  >> Cheers,
>  >> Magnus
> 
>  B> Sorry, but the waves looks like this:
> 
>  B>           /|        /|        /
>  B>          / |       / |       /
>  B>         /  |      /  |      /
>  B> 0V-----/   |-----/   |-----/
> 
>  B>      /|        /|        /|
>  B>     / |       / |       / |
>  B>    /  |      /  |      /  |
>  B> 0V/   |-----/   |-----/   |-----

>  B> Therefore the final sawtoth wave is twice in
>  B> frequecy of the sqare wave available at pin 3 .
> 
>  B> A nother nice thing with this design is the ability to get PWM
>  B> by the usage of the Xor gate.It generates 100% PWM, no need for
>  B> external comparator.infact one can get PWM and Ring mod at the same time
>  B> from the same Xor gate.
> 
>  B> In wich way did you have in mind to do the saw to tri conversation?
>  B> Im not so sure that you relly get a nice and clean tri wave due to the
>  B> "out of phase" acting by each saw! If one would phase reverse one of the
>  B> waves then you might get a tri! I have to try to see!

BJ 
again