Ok, folks, I have made some practical guide lines which I'll believe noone has had any objections against.
A good way to get some results is to grab simulation values for the parts in mind plus some extrapolations of what the physical circuit may add in terms of parasitics. Put those data into for example LTSpice, freeware. With Spice you can solve equations with some trial and error and by that forget about formulas.
I was trying to create a technical discussion but at the moment everyone agrees with me.
A good way to get some results is to grab simulation values for the parts in mind plus some extrapolations of what the physical circuit may add in terms of parasitics. Put those data into for example LTSpice, freeware. With Spice you can solve equations with some trial and error and by that forget about formulas.
I was trying to create a technical discussion but at the moment everyone agrees with me.
P-A asked always the same question, since the first post Carlos wrote on the subject. Carlos just wants to share his experience. For me, the snubber works very well in both configurations (unregulated and regulated PSU) used with a GC based on LM1875. It even works with a class T amp (SI).
I don't understand why Carlos should explain, more than he actually did in several threads, how and why the snubber works.
Keep on Carlos.
I don't understand why Carlos should explain, more than he actually did in several threads, how and why the snubber works.
Keep on Carlos.
@ PA:
Dude, don't say everyone agrees with you when they don't. Especially when the "originator" of the circuit does not agree.
All the snubber is, is a freaking impedance corrector/lower-er/whatever-you-want-to-call-it. It is not complicated.
The snubber works basically like this: if there is a frequency where the impedance is rather high, calculate a zobel for it. If it sounds good, then yay! If it doesn't sound good, measure some more and see if there are other peaks in the impedance, then repeat.
Stop being a *******.
Dude, don't say everyone agrees with you when they don't. Especially when the "originator" of the circuit does not agree. All the snubber is, is a freaking impedance corrector/lower-er/whatever-you-want-to-call-it. It is not complicated.
The snubber works basically like this: if there is a frequency where the impedance is rather high, calculate a zobel for it. If it sounds good, then yay! If it doesn't sound good, measure some more and see if there are other peaks in the impedance, then repeat.
Stop being a *******.
Indeed you are right but so far I haven't seen any theoretical text from Carlos which explains why he has come up with his circuit compared to a conventional snubberization. So far Thorsten, Joseph_k and janneman have done a good job putting light on the snubber. Excuse me if I have forgotten somebody worth mentioning.jram said:
I think we stop here unless someone has anything to say about my guide lines.
jean-paul said:Forget the past and join forcesMaybe we'll see a Per-Anders/CarlosFM snubber circuit in the near future
Rather a camel will fit through the eye of a needle before this will happen!
peranders said:
pls define everyone
instead of playing around with simulator tools, people should
do their homework. To discuss technical matters one should
have some theoretical background. It is not old fashioned to
know how to calculate some values.
Uli
Language Police Upupa Epops said:Once time 1 R / 100n, once time differrent value. Say why and we will be satisfied
With the unregulated PSU, lower impedance than I initially thought was needed is beneficial.
The resistor sets the impedance.
The cap sets the frequency.
A higher frequency than I initially thought was needed is also an improvement to this amp.
This was (is) work and development in progress.
Nothing comes spot-on at first time.
Who thinks otherwise is deeply wrong.
One of the many points where P-A is wrong some posts ago is that you can even go lower that 0.47R (0.5R in his words), it can be even better.
But I have been very busy lately, so you guys go
and report the results.Jesus!
interesting reading
Dont know that this would meet with Carlos approval but it is an interesting read. regards Moray james.
http://www.maxim-ic.com/appnotes.cfm/appnote_number/1062
Dont know that this would meet with Carlos approval but it is an interesting read. regards Moray james.
http://www.maxim-ic.com/appnotes.cfm/appnote_number/1062
Moray, you may not know but "snubber" isn't the right word for this, therefore you will get up the wrong documents. We call it snubber and this has been a tradition since a while back but it is still the wrong name for it.
Maybe we should call it the german way:
Impedance Peak Reduction Resistor", an IPRR
or:
"Stimolence exciter"
Stimolence is coming from the famous "Facancy analysis" which was created at Chalmers Univertsity of Technolgy. The whole thing was a joke but not everyone realized it. 50-100 pages of good scientific text of something but if you have a normal intellect you will understand 0%, not a thing, still some people believed that it was about sometihng.
What do you say? "Stimolence exciter" sound good, don't you agree?
Maybe we should call it the german way:
Impedance Peak Reduction Resistor", an IPRR
or:
"Stimolence exciter"Stimolence is coming from the famous "Facancy analysis" which was created at Chalmers Univertsity of Technolgy. The whole thing was a joke but not everyone realized it. 50-100 pages of good scientific text of something but if you have a normal intellect you will understand 0%, not a thing, still some people believed that it was about sometihng.
What do you say? "Stimolence exciter" sound good, don't you agree?
carlosfm said:
An externally hosted image should be here but it was not working when we last tested it.
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