[sdiy] saw/ramp from square?

[Magnus Danielson]

Dan Snazelle skrev:
> this article (on the DCO's in the JUNO)
> 
> http://www.electricdruid.net/images/dcos/larger/JunoDCOwaveshaper.gif
> 
> (from 
> http://www.electricdruid.net/index.php?page=info.junodcos
> 
> 
> 
> explains a process for getting a ramp from a square. however...i am a bit lost.
> 
> is this diagram showing that the square wave plugs straight into the base of the NPN after passing through some caps and resistors (is that an integrator?)
> 
> i would LOVE to be able to find a way to get pretty good (dont need to be perfect) ramp waves or (anything other than square) out of my square waves

It is a pretty straight-forward thing. You have a coarse CV that 
integrates up in an integrator, however, the DCO controls the reset, so 
what you got is a linear ramp but with the timing from the DCO. The 
control voltage is only needed to make the ramp have about the same 
amplitude regardless of frequency.

Cheers,
Magnus