Found this useful inductor calculator -- could be useful for those intending to roll their own.
Only thing I don;t get on the results generated (I'm thinking of a 2.2mh for my Mini-A PSU) is the column 'power'... with 12awg it gives 800watts and with 17awg (the aircore inductors I've so far been able to source cheaply) it gives 350watts -- imagine this is the power handling, no?
Only thing I don;t get on the results generated (I'm thinking of a 2.2mh for my Mini-A PSU) is the column 'power'... with 12awg it gives 800watts and with 17awg (the aircore inductors I've so far been able to source cheaply) it gives 350watts -- imagine this is the power handling, no?
my post was completely ignored
Not to offend anybody, but you guys asking question about Pi filtres on this thread ought to reed a book first.
Amazingly it has cover 5 or more pages on such simple matters as a wound conductor that most don’t care much about it after giving all the simple knowledge available plus links to suitable sites.
Just take a piece of insulated copper wire and wind it over a core, shoot for 2 or more mH and you are done. Now if you want to get picky about it dip it on electrical varnish and let it harden for a couple of days.
apassgear said:
Not to offend anybody, but you guys asking question about Pi filtres on this thread ought to reed a book first.
Amazingly it has cover 5 or more pages on such simple matters as a wound conductor that most don’t care much about it after giving all the simple knowledge available plus links to suitable sites.
Just take a piece of insulated copper wire and wind it over a core, shoot for 2 or more mH and you are done. Now if you want to get picky about it dip it on electrical varnish and let it harden for a couple of days.
my man....................
Stefanoo said:
thanks a lot for the suggestion Mr Pass.
I was using the following topology CLCLCRCC with R=3.3ohm.
So i'll try to lower this value
I would like to ask you guys, this things:
Since i was suggested that a regulated power supply is, in general if well done, better for a preamplifier
in case, would it be convenient to put the stab stage after clc... section or before?
To me, it lools more convenient t oput it after.
Do you guys have any suggestion on a good topology to implement to stabilyze the rail voltage (without using LM or any chip)?
The rail voltage that i should have is about 60V (the supply for the P1.7).
What ripple value can be considered to be VERY good?
Thanks a lot in advantage.
Best,
Stefano.
now read just two words:
SHUNT REG
few tips:
use CCS in front of shunt element
burn minimum same amount of current in reg -as load is
use minimum capacitance you can after reg
use one reg per stage
for preamp - if you make decent reg ( shunt or series,your choice) ripple value is already negligible , so why bother with numbers.......
edit:
first hit on google
http://tiny.pl/dbxh
I built my Aleph with 25VAC secondaries and 3 amp bias. The DC voltage came out to be 33 volts. The capacitors are 33,000mF with 0.56mH inductors in between (surplus, very cheap and large awg). The amount of AC ripple at the first capacitor is 153 mV. The second capacitor after the inductor sees 16.6 mv. Thats roughly a -20 dB reducton in ripple. If you do the math for XC=1/2pi F C and XL=2 pi F L, frequency being 120 Hz, it works out to be correct. The inductors XC has about 10 times the reactance as the capacitor so that gives you about -20dB. The amps are very quiet.
The point is even a small amount of inductance can give you great gains in noise reduction.
BDP
The point is even a small amount of inductance can give you great gains in noise reduction.
BDP
Attachments
Well I have a P1.7 type variation that Iv'e been rebuilding into a nicer package... I'm still working on my silly supply too, but it's almost done I don't use a regulator on the -20V rail but it has good filtering ("a bit exagerated" maybe). It also is connected to a current source wich will reject the supply noise further. I'm thinking of trying to build a regulator using an LU1014D on each positive rail though. Haven't seen anyone doing one of those yet??? I don't use the upper current sources like the 1.7. My circuit draws about 100mA per channel.
I have included a pic.. As you see it here, I can't measure any ripple with my scope on the 80V rail, (20mV/Div), (too small?). Using the DVM set to AC Volts it bounces around 1-5mV? I didn't actually have final grounding connected during those measurements...
I have a P1.7 type variation that Iv'e been rebuilding into a nicer package... I'm still working on my silly supply too, but it's almost done I don't use a regulator on the -20V rail but it has good filtering ("a bit exagerated" maybe). It also is connected to a current source wich will reject the supply noise further. I'm thinking of trying to build a regulator using an LU1014D on each positive rail though. Haven't seen anyone doing one of those yet??? I don't use the upper current sources like the 1.7. My circuit draws about 100mA per channel.I have included a pic.. As you see it here, I can't measure any ripple with my scope on the 80V rail, (20mV/Div), (too small?). Using the DVM set to AC Volts it bounces around 1-5mV? I didn't actually have final grounding connected during those measurements...
Attachments
Cloth Ears said:
Back in the '80s I reached a point when I couldn't find anything that I felt like reading and didn't have money anyway. (Just goes to show you how old I am...old enough to remember an era when people still read for pleasure. [Ohmigod! Dude you must be, like, ancient!]) For some peculiar reason the idea came to me to write something, myself. Too much blood in my alcohol stream, I guess. I tried it, found that I enjoyed the writing process, and decided to play with it for a while. 'A while' is now approaching twenty years.
It has been said that anyone can become an author--you just have to write a million words as practice. I got into the club cheap; only had to do about a hundred thousand before my first sale.
Grey
I confess that I'm of two minds regarding complicated circuits for folks with little or no experience. Part of me says, "Let 'em tackle a project with some meat on it." The other part says, "But then nine out of ten people get in over their heads and get disillusioned. Then they lose their will to diy, settle in front of a television, gain a hundred and fifty pounds, have a heart attack, and die. And being a notorious softie, I don't want their death on my conscience."
In the final analysis, it falls to the individual to answer honestly: Am I going to pull this off, regardless of difficulty, or is this just mental masturbation?
No, I said answer honestly...don't just tell me what you think I want to hear. After all, it's your money, your time, and your lover's patience. Don't overlook the importance of that last one. A lot of people don't understand the burden they place on others when they lose it and start banging their head against a wall. (I've got this special place where I've got the cinder blocks softened up enough that I barely feel the pain any more. Or maybe it's just that all my nerve endings gave up sending signals that went unheeded.)
Don't just tell me you feel the fire. I may or may not believe you. Lots of people claim to have the necessary passion, but not so many follow through.
Many are called. Few are chosen.
Abandon hope, all ye who enter here.
Here be dragons and things unknown...
Grey
In the final analysis, it falls to the individual to answer honestly: Am I going to pull this off, regardless of difficulty, or is this just mental masturbation?
No, I said answer honestly...don't just tell me what you think I want to hear. After all, it's your money, your time, and your lover's patience. Don't overlook the importance of that last one. A lot of people don't understand the burden they place on others when they lose it and start banging their head against a wall. (I've got this special place where I've got the cinder blocks softened up enough that I barely feel the pain any more. Or maybe it's just that all my nerve endings gave up sending signals that went unheeded.)
Don't just tell me you feel the fire. I may or may not believe you. Lots of people claim to have the necessary passion, but not so many follow through.
Many are called. Few are chosen.
Abandon hope, all ye who enter here.
Here be dragons and things unknown...
Grey
Mmm.
Stefanoo,
if you look closely you'll notice that a great many of the folks who enjoy the single ended Class A thingy share some personality flaws.
Some may grow their own veggies, and some are veggies.
Others enjoy Sci-Fi, quite a bunch like tinkering in general.
Looks like some sort of age time frame oddity thingy.
A generation that knows the value of cold hard cash, but still prefers conscious awareness as a way of meaningfull living.
Obviously, i'm one of the time framers too. I enjoy Sci-Fi, languages and reading, even read some of Mr Rollins's short hand. Some of us find metaphorical wanderings entertaining and meaningfull, occasionally.
(though buying a Rollins book on sleep deprivation is a no-no)
You've come quite a distance compared to the first post i read from you, but it looks as that you desire to read 1 book only and you are in a mighty hurry to finish it.
To get a meaningfull grasp on the operation of powersupplies, CLC or otherwise, maybe you should learn the basics or take a look at older stuff first. e.g. : check out the rails (and the ferrite coils) in the Mark Levinson ML2 schematic at Marklev.com
Otherwise you may be better off at a coil thread for the deaf who measure and Spice only.
I'm punching out, boss.
Stefanoo,
if you look closely you'll notice that a great many of the folks who enjoy the single ended Class A thingy share some personality flaws.
Some may grow their own veggies, and some are veggies.
Others enjoy Sci-Fi, quite a bunch like tinkering in general.
Looks like some sort of age time frame oddity thingy.
A generation that knows the value of cold hard cash, but still prefers conscious awareness as a way of meaningfull living.
Obviously, i'm one of the time framers too. I enjoy Sci-Fi, languages and reading, even read some of Mr Rollins's short hand. Some of us find metaphorical wanderings entertaining and meaningfull, occasionally.
(though buying a Rollins book on sleep deprivation is a no-no)
You've come quite a distance compared to the first post i read from you, but it looks as that you desire to read 1 book only and you are in a mighty hurry to finish it.
To get a meaningfull grasp on the operation of powersupplies, CLC or otherwise, maybe you should learn the basics or take a look at older stuff first. e.g. : check out the rails (and the ferrite coils) in the Mark Levinson ML2 schematic at Marklev.com
Otherwise you may be better off at a coil thread for the deaf who measure and Spice only.
I'm punching out, boss.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.