Re: Is it possible to simulate ac signal with dc?..tia sal



On 5/31/07 1:02 PM, in article C28477FC.69535%dbowey@xxxxxxxxxxx, "Don
Bowey" <dbowey@xxxxxxxxxxx> wrote:

On 5/31/07 10:06 AM, in article dgD7i.14714$RP4.1358@xxxxxxxxxxxxxxxxxxxx,
"Geoff R" <no@xxxxxxxxxxxxxxx> wrote:

Don Bowey wrote:
On 9/19/05 7:28 AM, in article FWzXe.10$tz3.1345@xxxxxxxxxxxxxxx, "Don
Stauffer" <stauffer@xxxxxxxxxxxx> wrote:

One problem with some of these discussions is that there are two
definitions of DC. One has DC as any signal always of the same polarity,
another requires DC to have the same value throughout time.

DC with a varying voltage but always the same polarity can of course be
changed to AC by running the signal through a capacitor.

Another problem I have seen whose argument reduces to the above is a
pulse width modulated signal but always of the same polarity (if you can
call zero volts a polarity- however, to overcome this problem one can
consider a PWM signal from a small fraction of a volt to many volts).

Another argument I have seen rage from the PWM situation is whether a
PWM signal is analog or digital :-)

Answering the practical question of a newbie with this type of
hypothetical/metaphysical nonsense is...... Well, garbage.

I wonder if these considerations of DC began with the musings of some
complete idiot, or some idiot with a phd attempting to think outside the box
(an incomplete idiot).

No, I think that this thread is finally onto what the original poster
wanted to know. i.e. does the voltage of the centre pin of the phono
connector stay above the ground connection or does the voltage alternate
between say -1v and +1v. Both of these would generate an audio signal
but only one would be true AC, the other would be pulsed DC.

Having said that, I still don't have an answer to the original poster's
question.

You attributed the post to me, but I didn't write any part of it.

Since I don't recall the original question, I have no comments.

Don


I went back and read the complete thread and looked through the patent file.

Here are my few comments:

The apparatus called for in the application requires both a Carrier
frequency that will vary in the range of 200 Hz. to 200 kHz., and a
Modulating frequency which will vary in the range of 20 Hz. To 200 Hz.
Obviously, an AM modulator is required, as is a Power Amplifier. Beyond
that it is all adaptive of frequencies and wave-shapes such that they can be
altered by the gas conversion process.

There is nothing in the computer's sound card that will enable the gas
conversion process.

Yes, your sound card puts out an AC signal (tones and whatever).

Don




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Relevant Pages

  • Re: Is it possible to simulate ac signal with dc?..tia sal
    ... One has DC as any signal always of the same polarity, ... > consider a PWM signal from a small fraction of a volt to many volts). ... > Another argument I have seen rage from the PWM situation is whether a ... complete idiot, or some idiot with a phd attempting to think outside the box ...
    (sci.electronics.misc)
  • Re: Is it possible to simulate ac signal with dc?..tia sal
    ... DC with a varying voltage but always the same polarity can of course be ... consider a PWM signal from a small fraction of a volt to many volts). ... complete idiot, or some idiot with a phd attempting to think outside the box ...
    (sci.electronics.misc)
  • Re: Is it possible to simulate ac signal with dc?..tia sal
    ... DC with a varying voltage but always the same polarity can of course be ... consider a PWM signal from a small fraction of a volt to many volts). ... complete idiot, or some idiot with a phd attempting to think outside the box ... i.e. does the voltage of the centre pin of the phono connector stay above the ground connection or does the voltage alternate between say -1v and +1v. ...
    (sci.electronics.misc)
  • Re: MIL-STD-188-114A vs. RS-232
    ... As I recall the main difference was polarity. ... We already have a SOT-23 dual transistor that should do the ... I will have to add a voltage inverter to generate -5 volts. ...
    (comp.arch.embedded)