sfogg Posted February 25, 2004 Share Posted February 25, 2004 Craig, "when you facvtor in what c harges the capacitor has nothing to so with the waveform and I also do not see how or why there would be any DC component to a wave form." Just consider that flat top of a perfect square wave... ignore the rest of the wave for a minute. What is its frequency? 0 hz. What is the frequency of DC? 0hz. Now look at the entire square wave. What is that 0hz component doing in relationship to the rest of the waveform? It is changing from positive to negative at whatever the frequency of the square wave is. Shawn Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 25, 2004 Author Share Posted February 25, 2004 Well I just measured the output of my function generator and there is really no measurable DC coming from its output when compared to the AC signal. At full output there is 15 VAC and the DC is in a MV range almost the same as if the probe was lying on the bench. I just don't get the point here. Craig Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 25, 2004 Author Share Posted February 25, 2004 Shawn, I really do not mean this as a insult but you just do not have the talent to put things in a context that I can grasp. I bet 5 minutes on the phone and I could grasp what your talking about. I know in a matter of second Mark Deneen would have me well versed in the entire subject. Mark has a way of explaining things so that almost anyone could understand. The more you type the more confused I become. Craig Quote Link to comment Share on other sites More sharing options...
sfogg Posted February 25, 2004 Share Posted February 25, 2004 "Well I just measured the output of my function generator and there is really no measurable DC coming from its output when compared to the AC signal. " OK... where is the 0 volt point in your square waves? That would be right down the horizontal middle of them. That means for one cycle half the dc 'component' (flat horizontal line at the top of the square wave) is positive and half (flat horizontal line at the bottom of the square wave) is negative. Your meter is summing those two components... guess what the result is? Zero. Shawn Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 25, 2004 Author Share Posted February 25, 2004 well then why is the AC 15 volts ??? Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 25, 2004 Author Share Posted February 25, 2004 Shawn, What do you do for a living ?? Craig Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted February 25, 2004 Share Posted February 25, 2004 ---------------- On 2/25/2004 5:22:23 PM NOSValves wrote: ---------------- On 2/25/2004 4:46:35 PM Guy Landau wrote: I just lost you guys, on that one. How the hell did we get all this scope talk? This boring thread should have been long gone.---------------- Boring to those with little minds ---------------- OTOH, I do enjoy your comments. Maybe you should put another one of your client's amps on the scope (Please, no names this time) , and start all over again? Maybe with better explanations - Or should we just ask Shawn or Jeff to do that (It seem like they know what they're talking about as opposed to........................) Quote Link to comment Share on other sites More sharing options...
sfogg Posted February 25, 2004 Share Posted February 25, 2004 "well then why is the AC 15 volts ???" Because AC by its very name alternates and you meter is measuring point to point. DC is referenced against ground. If your square wave is 10v point to point that means have (EDIT: half of) off its 'DC' is +5v the other half is -5v. Hence when it is summed you end up with zero. Shawn Quote Link to comment Share on other sites More sharing options...
sfogg Posted February 25, 2004 Share Posted February 25, 2004 Craig, Quick experiement for you to try to hopefully visualize this better. Hook up your voltmeter again to your function generator this time have it put out 2v P/P at 20hz on a sine wave. Measure the DC level. Change your function generator to square waves. Again measure its DC level. In both cases you should see it zero volts. Now insert a diode between the positive lead from your function generator and your voltmeter. Doesn't matter which way you insert the diode... one direction and it will block the positive component, the other direction and it will block the negative component. Remeasure the DC voltages on sine waves and square waves. Shawn Quote Link to comment Share on other sites More sharing options...
rigma Posted February 25, 2004 Share Posted February 25, 2004 gerbache, Where in TN do you live? I am near Nashville and have several tube and SS amps powering Klipschorns and LaScalla's. If you are close, I would be glad to have you over. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 25, 2004 Author Share Posted February 25, 2004 ---------------- On 2/25/2004 5:37:30 PM Guy Landau wrote: ---------------- On 2/25/2004 5:22:23 PM NOSValves wrote: ---------------- On 2/25/2004 4:46:35 PM Guy Landau wrote: I just lost you guys, on that one. How the hell did we get all this scope talk? This boring thread should have been long gone.---------------- Boring to those with little minds ---------------- OTOH, I do enjoy your comments. Maybe you should put another one of your client's amps on the scope (Please, no names this time) , and start all over again? Maybe with better explanations - Or should we just ask Shawn or Jeff to do that (It seem like thet know what they're talking about as opposed to........................) ---------------- I see you being your positive self as always ! Why don't you go help someone spend there money its seems to be all your good at Heh !! Whether I understand scope operation or not doesn't really matter now does it ! Its the results of my work that matter and they are wonderful as always !! I asked Alan if he minded me putting this up by the way . Craig Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted February 25, 2004 Share Posted February 25, 2004 Why should I help them spend money, if you already do such a wonderful job. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 25, 2004 Author Share Posted February 25, 2004 Well you know Guy some of us have to support are selves and are families. I'm pretty sure you would have a hard time understanding that Craig Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 25, 2004 Author Share Posted February 25, 2004 Now that is easy to understand ! You really should of been a college professor Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted February 25, 2004 Share Posted February 25, 2004 Shawn, you wrote: "If you make your scope distort the signals so that the input and output look the same (becaue of the scopes distortion) that is hiding the distortion of the amp and is misleading. Maybe you didn't intend to do that but hiding distortion was the end result. When you instead remove the scopes filtering (distortion) and show the actual signal input into the amp (without the additional filtering/distortion of the scope) and then show the actual signal coming out of the amp (without additional filtering in the scope) you see the distortion introduced by the amp itself." Maybe you should draw what you meant... Quote Link to comment Share on other sites More sharing options...
sfogg Posted February 25, 2004 Share Posted February 25, 2004 "Maybe you should draw what you meant..." Basically, just take what Mark did and change the output from the device under test from a perfect square wave to one with a little distortion but not as bad as what the scopes filtering is doing. Leave everything else the same. The input/output displays on the scope are still going to look the same because the distortion of the wave by the scopes filtering is much higher then what the amp is doing to the square wave. IOW, the amps distortion is hidden by the distortion introduced from the scopes filtering. When the distortion of the amp surpasses the distortion of the scopes filtering then the input/output will look different. Shawn Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted February 25, 2004 Share Posted February 25, 2004 Shawn, I'm OK without a drawing. I was asking as an altruist! Quote Link to comment Share on other sites More sharing options...
sfogg Posted February 25, 2004 Share Posted February 25, 2004 I know, I was just trying to help others visualize what I've been trying to get across for awhile now. Shawn Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 25, 2004 Author Share Posted February 25, 2004 Mr Painfull Do you even own a scope ?? Quote Link to comment Share on other sites More sharing options...
gerbache Posted February 25, 2004 Share Posted February 25, 2004 I'm in Knoxville, at the University of Tennessee, to be exact. Not terribly far from Nashville, depending on what part of town we're talking about. Quote Link to comment Share on other sites More sharing options...
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