FETs on the ASM-1 VCO.

[Fraser, Colin J]

> -----Original Message-----
> From: Arthur Harrison [mailto:theremin1 at worldnet.att.net]
> Sent: 16 December 1998 00:53
> To: DIY
> Subject: Re: FETs on the ASM-1 VCO.
> 
> 
> Has anyone considered using an integrated analog switch
> for the integrator reset?  (Or would that disqualify the oscillator
> from being a true "clone?")  These parts are available in a
> variety of form factors, and some newer devices have Rds(ON)
> specifications of 5 ohms, and very little charge injection.
> Maxim and Analog Devices come to mind as possible sources.
> (No pun intended!

I think I'll give this a try over my christmas holiday (if I can keep away
from Tomb Raider 3 long enough...)
I want to add a bit of extra logic to allow reset of the oscillator to a
halfway point. This is to allow for normal oscillator sync plus an extra
sync mode that resets a tri-wave output to the start or midpoint of its
cycle depending on its current position.
Maybe another sync mode with voltage control of reset point will be useful.
This should be pretty easy with analogue switches, as long as I can find one
with very low on resistance.

Colin f