FWD:Re: [sdiy] 2 Diode ring modulator rough designs - request advice

[John L Marshall]

I agree those circuits a confusing. I was trying to do a logical trace of
the circuits. The obvious goal is to have two inputs X and Y such that each
is balanced to produce no output. But, Signal X will unbalance Y and Signal
Y will unbalance X.

Your circuit may be just fine. It is just different than the two transformer
method. I will look at your circuit again later this evening.


Take care,
John
---------------------------------------------------------------------------
Pacific Northwest DIY Synthesizer meeting, July 20, 2002
See: www.sound-photo.com
---------------------------------------------------------------------------

----- Original Message -----
From: "Scott Gravenhorst" <music.maker at gte.net>
To: <john.l.marshall at gte.net>; <synth-diy at dropmix.xs4all.nl>
Sent: Monday, July 22, 2002 8:56 AM
Subject: FWD:Re: [sdiy] 2 Diode ring modulator rough designs - request
advice


> I don't know what happened, but I never saw this posted
> to the list, so I'll try once more.
>
> ------- FORWARDED MESSAGE FOLLOWS -------
>
> Sorry about that, I hit the wrong button.
>
> Looking at the basic circuit I got (Jaroslav Lukesh) was marked:
>
> C(t)                     Um(t)
> [Um(t)]  on the right    [C(t)]  on the left
>
> and the resistors forming a voltage divider were marked U2(t)
>
> I took 'C' to mean carrier, but now I realize this might not
> be true since it was written in a language I don't understand.
>
> In the transformer one on the same page, the center taps of the
> transformers is labeled C(t), the windings on the other side
> of the transformers are marked Um(t) and U2(t).
>
> Are you saying that the two "U" connections are inputs and the
> "C" connection (center taps) is the output?
>
> I've never played with this, but since carrier and input can often
> be swapped, I interpreted it this way.
>
> Then I looked around for examples of other transformer ones and
> can't seem to find them now.
>
> Thanks.
>
> "John L Marshall" <john.l.marshall at gte.net> wrote:
> >Aren't your "Y" input and output swapped?
> >
> >
> >Take care,
> >John
>
>---------------------------------------------------------------------------
> >Pacific Northwest DIY Synthesizer meeting, July 20, 2002
> >See: www.sound-photo.com
>
>---------------------------------------------------------------------------
> >
> >----- Original Message -----
> >From: "Scott Gravenhorst" <music.maker at gte.net>
> >To: <synth-diy at dropmix.xs4all.nl>
> >Sent: Saturday, July 20, 2002 11:55 AM
> >Subject: [sdiy] 2 Diode ring modulator rough designs - request advice
> >
> >
> >> http://home1.gte.net/res0658s/diode_ring_modulators.html
> >>
> >> There are two rough designs here.  One uses transistor phase
> >> splitters, the other uses 4069 inverters in linear amp mode
> >> to achieve the required inverted and non inverted copies of
> >> the input signals.
> >>
> >> What I see in the 4069 design is an issue with current flow
> >> through the diodes (and drive MOSFETs) on input X.  I am not
> >> terribly concerned about distortion.
> >>
> >> Should I put small series current limit resistors to feed
> >> the X side of the ring?
> >>
> >> In the discrete design, should I power this with a dual supply?
> >>
> >> Any other comments regarding design flaws?
> >>
> >> Opinions on which has a better chance of working at all?
> >>
> >>
> >> Thank you for your time.
> >>
> >>
> >> =========================================================
> >> - What good are laws that only lawyers understand?
> >> - Government: The other religion.
> >> - The media's credibility should always be questioned.
> >> - Lambs who lie down with lions are lunch.
> >>
> >> -- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
> >> -- Linux Rex         | RedWebMail by RedStarWare
> >> -- FatMan: home1.GTE.NET/res0658s/FatMan/
> >> -- NonFatMan: home1.GTE.NET/res0658s/electronics/
> >>
> >>
> >
>
> =========================================================
> - What good are laws that only lawyers understand?
> - Government: The other religion.
> - The media's credibility should always be questioned.
> - Lambs who lie down with lions are lunch.
>
> -- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
> -- Linux Rex         | RedWebMail by RedStarWare
> -- FatMan: home1.GTE.NET/res0658s/FatMan/
> -- NonFatMan: home1.GTE.NET/res0658s/electronics/
>
>