Silonex NSL32-SR3 Opto-coupler Spice Model

Started by Eb7+9, October 04, 2008, 03:31:17 PM

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Eb7+9

something I came up with last fall that has been quite useful ... might as well put it out there

http://isp.lynx.net/~jc/NSL32-SR3modeling.html

MetalGuy

One thing I noticed about NSL32-SR3 is they have very SLOW response time.

R.G.

If you want to including timing, I've had great success with modelling the time response of LED/LDR pairs by putting the time dependency ahead of the control voltage, in the form of RC delays and leaving the outgoing resistance be an instantaneous change.

Of course, that does require diodes to separate currents going in from going out, which may be what you were alluding to not liking do to.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

Eb7+9

Quote from: MetalGuy on October 04, 2008, 06:49:43 PM
One thing I noticed about NSL32-SR3 is they have very SLOW response time.

depends how you use them, they're high sensitivity and more prone to getting stuck when used as a switch ... for low current control they're pretty speedy ...

MetalGuy

I tried to use them in an EPFM  noise gate but they "close" very slowly. Tried them also for muting - in that case they "open" slowly. Didn't try them for switching though.

Eb7+9

that's pretty typical of opto-couplers - you see that with all of them, incl. the Vactrols ... in some tube amps (eg Mesa) they'll piggy back two cells to halve the "on" resistance which helps minimize the release time somewhat ... I haven't checked out the gate circuit you mention but it's likely driving the LED too hard ... the SR3 needs careful attention to drive levels - hence the Spice model ...

MetalGuy

Quotethat's pretty typical of opto-couplers

I've tried VTL5C1 and 3/2, NSL32-SR3, some DIY ones made from NSL6112, NSL5162, VT935G-A but the fastest optocoupler was a DIY one made from unknown brand glass encapsulated photocell with ~200 Ohm ON resistance and more than 200 MOhm OFF.