[sdiy] 3340 FET sync

[Finlay Shakespeare]

Hi Neil,

D'oh! That makes total sense and, of course, makes it work perfectly. Now to hack a decent enough reference into the current prototype.

Thanks everyone!

Cheers!
Fin

________________________________
From: Neil Johnson <neil.johnson71 at gmail.com>
Sent: 21 January 2020 15:49
To: Finlay Shakespeare <futureimage at hotmail.co.uk>
Cc: Synth DIY <synth-diy at synth-diy.org>; Oakley Sound <oakleysound at btinternet.com>
Subject: Re: [sdiy] 3340 FET sync

Hi Finlay,

> The behaviour that I'm seeing from the 3340 is close to how Tony describes.
> The triangle waveform at pin 10 is exactly as described in the datasheet, but the "triangle" across the timing cap at pin 11 is bang on +2V to +6V...

Ok, so in that case you CANNOT short the capacitor to 0V as you are
currently doing.  For this to work you need to recreate the lower
internal threshold voltage and short the capacitor to that, not 0V.

Neil
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