[sdiy] Fairchild H11F1

[Gene Stopp]

This looks like a really neat device for phasors and VC envelope generators,
or anything where you want to piggy-back to an existing circuit to make it
controllable. I have a cabinet-mounted programmable Minimoog that has
Vac-Tecs soldered across the envelope pots and filter emphasis, and this
looks like it would provide a great way to do the same thing.

- Gene



-----Original Message-----
From: Scott Gravenhorst [mailto:music.maker at gte.net]
Sent: Wednesday, July 31, 2002 11:26 AM
To: synth-diy at dropmix.xs4all.nl
Subject: [sdiy] Fairchild H11F1


This is an optoisolator bipolar FET device that can be used
as a "remote variable resistor".

Specs:
<=100 ohms to >= 300 meg ohms
>= 99.9 % linearity (not sure what this means exactly)
<= 15 pF shunt capacitance
60 volt p-p signal capability
25 uSec turn-on and turn-off time  (toggles at 40 kHz ?)

They mentions active filter tuning as an application.

Has anyone here messed with this?  Could this be used in a
typical SVF for voltage controlling resonance (normally a
series variable resistor)?

http://www.fairchildsemi.com/pf/H1/H11F1.html