[sdiy] Possible to Hard-Sync R. Schmitz CMOS VCO???

[Needham, Alan]

I can't say this is guaranteed but:-
T2 sinks current from the integrator input pin, causing the capacitor to charge as the integrator output constantly rises to compensate.
The Schmitt trigger will eventually trip, it's output going positive, this will dump current through the diode and into the capacitor (effectively discharging it).
So...
A second diode connected to T2's collector could be used to reset the integrator in the same fashion (cathode to collector).
Any positive pulse on this diode's anode would then act as a synch signal.
This is a bit minimal - no protection or buffering (do NOT take this input more positive than +Ub) but is a starting point!
If a constant positive is supplied, the integrator will stay reset.


-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of cheater cheater
Sent: 03 November 2009 10:44
To: cs e
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] Possible to Hard-Sync R. Schmitz CMOS VCO???

seconded

On Tue, Nov 3, 2009 at 00:41, cs e <modulemania at gmail.com> wrote:
> How would someone go about adding hard-sync to Rene Schmitz's CMOS VCO
> (as seen here, in beautiful detail:
> http://www.uni-bonn.de/~uzs159/vco4069.html   ?
>
> I would appreciate to read anyone's process/analysis of determining
> the possibility of adding sync; and of course I would love to read how
> to do it ;-)
>
> Thanks
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

_____________________________________________________________________
The information contained in or attached to this email is intended only for the use of the individual or entity to which it is addressed. If you are not the intended recipient, or a person responsible for delivering it to the intended recipient, you are not authorised to and must not disclose, copy,distribute, or retain this message or any part of it. It may contain information which is confidential and/or covered by legal professional or other privilege (or other rules or laws with similar effect in jurisdictions outside England and Wales).

The views expressed in this email are not necessarily the views of Centrica plc, and the company, its directors, officers or employees make no representation or accept any liability for its accuracy or completeness unless expressly stated to the contrary.

A Centrica business British Gas Services Limited is authorised and regulated by the Financial Services Authority for its insurance mediation activities.

Registered office: Millstream, Maidenhead Road, Windsor, Berkshire SL4 5GD

Registered in England No 3141243.  

Centrica plc

Registered office: Millstream, Maidenhead Road, Windsor, Berkshire SL4 5GD

Registered in England and Wales No 3033654