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

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

.

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 ... Modulating frequency which will vary in the range of 20 Hz. ...
    (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: VFD question
    ... So if I wire one up to 240..does it mean that it will REDUCE the voltage ... Or is the output 24 volts? ... reduce the mains voltage by 24 V, depending on the polarity. ...
    (rec.crafts.metalworking)
  • Re: AC adaptor polarity
    ... Yes the mm has a polarity indicator and I've cleared that up now. ... And now it becomes apparent to me that the voltage would be higher when the ... Perhaps a regulated adapter would be safest as the chess unit is 600 Aust. ... > Can you see a difference if you shift the probe leads, ...
    (sci.electronics.basics)