[sdiy] New VCO... maybe...

[Roman Sowa]

Thanks.
Franco compensation should work here the same as in any ramp oscillator. 
But also as in other topologies might as well spoil the sawtooth shape 
at higher frequencies.
Nevertheless worth trying.

Roman

W dniu 2020-12-10 o 11:12, Richie Burnett pisze:
> That's neat Roman!  I enjoyed reading the write up too.
> 
> Can you compensate for the reset time in the usual way with a carefully 
> chosen resistor in series with the integrator capacitor?  Or won't that 
> work in this topology?
> 
> -Richie,
> 
> 
> 
> -----Original Message----- From: Roman Sowa
> Sent: Thursday, December 10, 2020 9:42 AM
> To: Spiros Makris
> Cc: SYNTH DIY
> Subject: Re: [sdiy] New VCO... maybe...
> 
> The idea behind it was to keep parts count low. I's appealing when one
> 14-pin chip does basicaly all.
> I plan to use comparator and dual opamps instead of quad in SMD version
> of it. But I don't expect much improvement, 500ns instead of 2us reset
> time by the cost of using completely different ICs would be huge success.
> If my estimations are correct, current HF tracking error is 15 cents at
> 4kHz, while with 0.5us reset it could go down to 4 cents. Some sort of
> compensation is probably simpler than speeding up the circuit.
> 
> Roman
> 
> W dniu 2020-12-10 o 09:44, Spiros Makris pisze:
>> Have you tried using a dedicated comparator IC instead of an opamp? 
>> Opamps make pretty bad comparators in practice, perhaps you can extend 
>> your range somewhat by changing it.
>>
>> On Thu, Dec 10, 2020 at 9:49 AM Roman Sowa <modular at go2.pl 
>> <mailto:modular at go2.pl>> wrote:
>>
>>     That still would be better than turning this list into C
>>     programmer's chat.
>>
>>     Also please, no disrespect to anybody
>>
>>     Roman
>>
>>     W dniu 2020-12-10 o 05:11, Shawn Rakestraw pisze:
>>      > I am patiently waiting for Mr Hutchins to split the thread off 
>> into
>>      > his own and lead off with a paper about why making CDs won't work,
>>      > then explain that this has already been done.
>>      >
>>      > And PLEASE take this with the humor that I intend it as! No
>>      > disrespect, just humor :)
>>      >
>>      > On Wed, Dec 9, 2020 at 6:21 PM Aaron B. <aaron at zadzmo.org
>>     <mailto:aaron at zadzmo.org>
>>      > <mailto:aaron at zadzmo.org <mailto:aaron at zadzmo.org>>> wrote:
>>      >
>>      >     On Wed, 9 Dec 2020 22:56:22 +0100
>>      >     Roman Sowa <modular at go2.pl <mailto:modular at go2.pl>
>>     <mailto:modular at go2.pl <mailto:modular at go2.pl>>> wrote:
>>      >
>>      >     > I haven't used that phrase for long, so here it goes:
>>      >     > Comments welcome!
>>      >     >
>>      >
>>
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