In Reply to: Yo John posted by Dan Banquer on March 21, 2007 at 05:19:59:
db: ""
Are you sure about this? I have never seen any plots that would indicate that the above is correct.""Guess you don't get out much, eh?? Don't you remember Time Tunnel?? That huge lissajous? :-)
The equations are easy. When you plot the voltage and current of a reactive load, it doesn't go through the origion. It's also easy to see on a scope.
The easiest way is on a 576 curve tracer in AC mode..but it's still easy with a speaker and music. After all, it's just phasor analysis.. Make a simple current viewing resistor, say 100 milliohms, and use it's drop for the scope vertical, the amp output voltage as the horizontal, and any speaker as the load..if it's pure resistive, it'll be a straight line through the origin..regardless of the musical content.. But any reactance will cause the line to form an ellipse..that means operation in 2 and 4 as well as 1 and 3..but be careful of the .1 ohm resistor, it'll also have a non trivial b dot error component at typical audio frequencies, so any measurements you get will be useless unless you make the CVR correctly.
As for speakers and reactance?? Guess you don't listen to those resonators much, eh? One note wonders made for cars.
Sheesh, even the SWTPC 250 had SOA protection which extended into quadrant 2 and 4..waaay back then..
Amp design/system reactance is important in two applications. First, when the user is beatin the livin hell outta the amp...which I tend to do...:-( ..second, when one is nitpicking the daylights outta the image reconstruction parameters. (which I can't be bothered with given today's recording/delivery technology).
Cheers, John
Cheers, John
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Follow Ups
- Re: Yo John - jneutron 06:17:29 03/21/07 (19)
- Re: Yo John - Dan Banquer 06:48:46 03/21/07 (18)
- Re: Yo John - jneutron 07:13:23 03/21/07 (17)
- Re: Yo John - Dan Banquer 07:37:53 03/21/07 (16)
- Re: Yo John - jneutron 08:51:29 03/21/07 (15)
- Re: Yo John - Dan Banquer 09:55:39 03/21/07 (14)
- Re: Yo John - jneutron 10:05:43 03/21/07 (13)
- Re: Yo John - morricab 03:31:08 03/22/07 (5)
- Re: Yo John - jneutron 06:20:46 03/22/07 (4)
- Re: Yo John - morricab 15:25:02 03/22/07 (3)
- Re: Yo John - jneutron 06:34:23 03/23/07 (2)
- Re: Yo John - morricab 08:56:56 03/23/07 (1)
- Re: Yo John - jneutron 11:34:23 03/23/07 (0)
- Re: Yo John - Dan Banquer 11:05:33 03/21/07 (6)
- Re: Yo John - jneutron 11:46:10 03/21/07 (5)
- Re: Yo John - Dan Banquer 11:53:52 03/21/07 (4)
- Re: Yo John - jneutron 12:07:04 03/21/07 (3)
- Re: Yo John - Dan Banquer 12:17:56 03/21/07 (2)
- you have mail. Do us a favor, start a new thread - jneutron 13:20:02 03/21/07 (0)
- Re: Yo John - jneutron 12:44:01 03/21/07 (0)