Nice replys
The Mouser stock number is:
553-CMT908-V1 It IS in mH and it does say 2.0 mH.
The description goes as follows:
Highly dependable Triad common model EMI supression inductors are used in various types of power supplies to eliminate noise common to all lines. These units also provide effective differential mode filtering.....they minimize AC line transmitted interference often created by high frequency switching power supplies.
I agree they don't talk about dripping voltage or high saturation points, but they clearly say power supply.
There is another one 553-FIT44-1, they are in pH so I suspect they are too small.
Mouser doesn't seem to have a big selection of anything, I'm ready to call Digikey.
C
The Mouser stock number is:
553-CMT908-V1 It IS in mH and it does say 2.0 mH.
The description goes as follows:
Highly dependable Triad common model EMI supression inductors are used in various types of power supplies to eliminate noise common to all lines. These units also provide effective differential mode filtering.....they minimize AC line transmitted interference often created by high frequency switching power supplies.
I agree they don't talk about dripping voltage or high saturation points, but they clearly say power supply.
There is another one 553-FIT44-1, they are in pH so I suspect they are too small.
Mouser doesn't seem to have a big selection of anything, I'm ready to call Digikey.
C
You don't actually need air-cored inductors to get the effect, so that means you can have higher L and lower cost. You already have quite a bit of iron in the supply courtesy of the main transformer ...
A very positive side-effect of using an LC model is that you can extract more power out of the transformer than without an inductor (assuming component values chosen correctly).
The effect of pulse shortening in an C type supply is almost sickening and the reason that oversized transformers are used. The more C you put in, the shorter the pulse, and the lower the utilization of the transformer, the higher spikes imposed on the power system of your house etc. These pulses happen 100-120 times per second depending on where you are, and are very very large even though average current is typically low. I would guess 2+ orders of magnitude larger than average, depending on how your equipment is built of course.
Nelson's basic (and somewhat oversimplified) explanation of the effect of an inductor is accurate enough to for understanding of the concept.
A way to get a little bit of both is to use an CLC filter where the first C is small enough that it does not undo too much of the good of the LC (by pulsing the transformer), while taking rather a lot of spiking off the supply, reducing strain on rectifiers (watch out for reverse voltages!) and reducing the peak current of the inductor. The effect of the inductor is of course reduced. This also allows you to loose less voltage than you do from the pure LC filter if that is a problem for you.
Use PSUD2 to simulate, and try to put a 1uF (high quality in real life!!!) capacitor for the first C in a CLC setup and you will likely see what I mean. Then experiment with PSUD2 before building something suitable.
Petter
A very positive side-effect of using an LC model is that you can extract more power out of the transformer than without an inductor (assuming component values chosen correctly).
The effect of pulse shortening in an C type supply is almost sickening and the reason that oversized transformers are used. The more C you put in, the shorter the pulse, and the lower the utilization of the transformer, the higher spikes imposed on the power system of your house etc. These pulses happen 100-120 times per second depending on where you are, and are very very large even though average current is typically low. I would guess 2+ orders of magnitude larger than average, depending on how your equipment is built of course.
Nelson's basic (and somewhat oversimplified) explanation of the effect of an inductor is accurate enough to for understanding of the concept.
A way to get a little bit of both is to use an CLC filter where the first C is small enough that it does not undo too much of the good of the LC (by pulsing the transformer), while taking rather a lot of spiking off the supply, reducing strain on rectifiers (watch out for reverse voltages!) and reducing the peak current of the inductor. The effect of the inductor is of course reduced. This also allows you to loose less voltage than you do from the pure LC filter if that is a problem for you.
Use PSUD2 to simulate, and try to put a 1uF (high quality in real life!!!) capacitor for the first C in a CLC setup and you will likely see what I mean. Then experiment with PSUD2 before building something suitable.
Petter
I'm short on time again (you're surprised?), but I thought that I would address the Aleph-X who-did-what-when issue that yldouright raised a day or two ago with a short timeline:
3/29/01--I first raised the possibility in Petter's X-100 thread that the Aleph and X topologies might be compatible. Post #50.
3/30/01--Nelson posted that variants existed and that the concept worked. Post #62.
11-12/01--I spent a month or more looking at variations on paper, trying to figure out how to glue the two together. The schematics that I still have on hand are computer-generated, dated late December; the pen-and-paper trial versions (the way I usually work) are all gone and were undated at any rate.
Somewhere right at the end of 2001, or perhaps the first day or two of 2002, I e-mailed a schematic to Nelson asking if it would constitute a valid mating of the two topologies. In particular, I remember being concerned that the crossing over of the feedback from one side of the amp to the other wouldn't be "X." I've got a hardcopy of the e-mail somewhere if anyone is interested in the precise dates, but can't guarantee that I can lay hands on it quickly.
Much to my surprise, Nelson replied in an hour, saying that it was similar to new commercial product that they would be introducing at the CES in just a few days' time. He asked me to keep quiet about the idea until after the show. Then the scoundrel went and let the cat out of the bag while still at the CES, as I recall.
I spent the next couple of months working up a prototype, putting in an hour or two per night, usually between 1 and 3AM. I got pretty surly after a bit (all due credit to my wife, who had to live with me during that period). I'm used to getting by on very little sleep, but it got pretty extreme. (In particular, I felt obliged to apologize to Joe Berry for simply stopping e-mail during that period. Rude of me.)
Nelson had indicated that there would be a DC offset problem if I built the circuit according to the first schematic that I sent. I scratched out fifteen or twenty ideas that might or might not work before I even started the prototype. One of them was the resistor to ground at the each ouput, but I used 1k resistors. I mentioned to Nelson that I was able to get the DC within reasonable limits but that it wouldn't stay put. He suggested that I drop in 30 ohm resistors. I would never have considered using a value that low--I thought 1k was getting a little on the low side--and appreciate his help on that point as I would probably would have had to resort to a servo--something I wanted to avoid doing, if possible. I even had the resistors back to the tail of the differential thing, but discarded it like a fool. Credit to Ian for bringing it back into play.
5/24/02--I opened the Aleph-X thread
I have a few ideas in mind that might be fun to use in a version 2.0, but I'm seriously backlogged: three circuits I've been commisioned to build and just found out today that I've sold another story...but that the editor wants changes. And me with a 2 year-old who needs constant attention. Not to mention a phono stage I'm working on and yet another (tube, this time) iteration of my crossover. Clearly, something has to give, as I don't know at this point how I'm going to manage all this. I can probably deliver the tube preamp I promised in another thread fairly soon, as I've done considerable work on the concept, just need to organize a few things. I've also threatened a Ver. 2.0 Mini-A, which would be a stepping stone to the 2.0 A-X if I can just get some time.
We'll see what happens. Usually at this point in the game I plead for patience from those who might be interested in new projects. At this point, I'll be honest...I'm the one who is losing patience. Got ideas, but no way to bring them to fruition.
Grrrr....
Grey
3/29/01--I first raised the possibility in Petter's X-100 thread that the Aleph and X topologies might be compatible. Post #50.
3/30/01--Nelson posted that variants existed and that the concept worked. Post #62.
11-12/01--I spent a month or more looking at variations on paper, trying to figure out how to glue the two together. The schematics that I still have on hand are computer-generated, dated late December; the pen-and-paper trial versions (the way I usually work) are all gone and were undated at any rate.
Somewhere right at the end of 2001, or perhaps the first day or two of 2002, I e-mailed a schematic to Nelson asking if it would constitute a valid mating of the two topologies. In particular, I remember being concerned that the crossing over of the feedback from one side of the amp to the other wouldn't be "X." I've got a hardcopy of the e-mail somewhere if anyone is interested in the precise dates, but can't guarantee that I can lay hands on it quickly.
Much to my surprise, Nelson replied in an hour, saying that it was similar to new commercial product that they would be introducing at the CES in just a few days' time. He asked me to keep quiet about the idea until after the show. Then the scoundrel went and let the cat out of the bag while still at the CES, as I recall.
I spent the next couple of months working up a prototype, putting in an hour or two per night, usually between 1 and 3AM. I got pretty surly after a bit (all due credit to my wife, who had to live with me during that period). I'm used to getting by on very little sleep, but it got pretty extreme. (In particular, I felt obliged to apologize to Joe Berry for simply stopping e-mail during that period. Rude of me.)
Nelson had indicated that there would be a DC offset problem if I built the circuit according to the first schematic that I sent. I scratched out fifteen or twenty ideas that might or might not work before I even started the prototype. One of them was the resistor to ground at the each ouput, but I used 1k resistors. I mentioned to Nelson that I was able to get the DC within reasonable limits but that it wouldn't stay put. He suggested that I drop in 30 ohm resistors. I would never have considered using a value that low--I thought 1k was getting a little on the low side--and appreciate his help on that point as I would probably would have had to resort to a servo--something I wanted to avoid doing, if possible. I even had the resistors back to the tail of the differential thing, but discarded it like a fool. Credit to Ian for bringing it back into play.
5/24/02--I opened the Aleph-X thread
I have a few ideas in mind that might be fun to use in a version 2.0, but I'm seriously backlogged: three circuits I've been commisioned to build and just found out today that I've sold another story...but that the editor wants changes. And me with a 2 year-old who needs constant attention. Not to mention a phono stage I'm working on and yet another (tube, this time) iteration of my crossover. Clearly, something has to give, as I don't know at this point how I'm going to manage all this. I can probably deliver the tube preamp I promised in another thread fairly soon, as I've done considerable work on the concept, just need to organize a few things. I've also threatened a Ver. 2.0 Mini-A, which would be a stepping stone to the 2.0 A-X if I can just get some time.
We'll see what happens. Usually at this point in the game I plead for patience from those who might be interested in new projects. At this point, I'll be honest...I'm the one who is losing patience. Got ideas, but no way to bring them to fruition.
Grrrr....
Grey
That's pretty much how I remembered it, and has
been described before. We probably should not
expect people to read every ancient posting, so
some time in the future it will come up again.
😎
been described before. We probably should not
expect people to read every ancient posting, so
some time in the future it will come up again.
😎
Nah, I don't expect folks to be able to remember all that. Especially if they never knew it. A lot of the principle characters in those days are gone, and the new folks wouldn't know.
It would help if the search engine here didn't flake out on even the simplest searches. I tried searching for Aleph-X and the stupid thing couldn't even find the original thread.
Harrumph!
Fortunately, I made hardcopies of all our (Nelson/me) e-mails. Otherwise, I would have lost all documentation during the virus attack and, later, disk crash. Ain't computers wonderful? Paperless office, my (mumble)! You want something safe, you put it on paper.
That leaves begging the question of where to find said hardcopies, but I know two or three places I can look if it matters enough.
Grey
It would help if the search engine here didn't flake out on even the simplest searches. I tried searching for Aleph-X and the stupid thing couldn't even find the original thread.
Harrumph!
Fortunately, I made hardcopies of all our (Nelson/me) e-mails. Otherwise, I would have lost all documentation during the virus attack and, later, disk crash. Ain't computers wonderful? Paperless office, my (mumble)! You want something safe, you put it on paper.
That leaves begging the question of where to find said hardcopies, but I know two or three places I can look if it matters enough.
Grey
GRollins said:
The meaning the same as got no idea.
O... comon, let us know them, even if very brief... 🙂
Clarkcr said:
Clarkcr-
I'm in McKinney. I have a friend in Sachse and just about to drive to his house...
Maybe we should get together and listen to some music one night.
I just mailed off my Proceed AVP today so it can be upgraded therefore I'm down for a couple of weeks, but my friend will host us for a few of hours..
We used to do Friday or Saturday listening where we mixed and matched components 2-3 times a month.
Also I would be happy to assist in building or testing new gear.
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