can I use this: http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=255-808
I am not sure if 14AWG is enough to handle the current of a Pass Labs amp.
I am not sure if 14AWG is enough to handle the current of a Pass Labs amp.
I was talking (OK! OK! email) to Steve (ApexJR) the other day. He thought he could get "either 2 or 3 (of his 8mH inductors) in a Priority Mail Flat Rate International Box which can ship for $39.50". That would be 2 of these monsters, plus postage, to your door for $79.50 in US dollars - which under $94 Australian before you pay conversion fees (if they are applicable).jarthel said:
And I think they're 8awg, which is more than enough for anyones purposes...
John Broskie of the Tube Cad Journal mentions a trick of using
a iron core choke in seriese with an air core choke sort of like
using a good bypass cap with that electrolitic cap. I saw this
used in an OTL amp that used a choke loaded cathode fowler
and always wondered why they did this. So in the case of a
power amp maby a 10mh high current iron core and a .5mh
air core might be an idea?
a iron core choke in seriese with an air core choke sort of like
using a good bypass cap with that electrolitic cap. I saw this
used in an OTL amp that used a choke loaded cathode fowler
and always wondered why they did this. So in the case of a
power amp maby a 10mh high current iron core and a .5mh
air core might be an idea?
Attachments
jarthel said:amplifier will be F4. the service manual does not have the current rating for the transformer.
1 power supply for both channels.
Thank you
service manual of F4 tells you all- power,current everything
~1,5A per rail - per channel . so your chokes ( one in + and one in - ) must be good for at least 3A DC .
NP sez in servman that current draw for both channels is ~160W .
multiple that with 2,3,4,50 ..........whatever you fave number is.
go to NP's Pass and FW site and download every pdf you can.
and read
he even made effort to wrote one on PS topic.....
Magura said:You guys really know how to turn simple things real complicated
Magura
Considering that this is the third or fourth inductor-in-power-supply thread we've had in the last six months and that the threads keep turning absurdly Byzantine, I have to say that I agree.
I'll grant that the search function here leaves a bit to be desired, but surely it's up to locating the word "inductor," possibly even in conjunction with "power" and "supply."
Grey
Zen Mod said:
can you point me to the right page?
I am reading: http://www.firstwatt.com/downloads/f4_om.pdf and cannot find what you said.
I know you said to download all the PDFs but the only PDF related to the F4 is the one I linked above.
Thank you.
GRollins said:
Has anyone using LC input in their power supply?
PI-filter (or CLC vs CRC vs C)
inductors for Aleph X PSU
PI-Filter
PS question - CLC vs C filtering
First Pass project, need Aleph-M PSU advice please
proper design of pi-filter for Aleph 30
pi-filter Power supply for Alephs
choke for the power supply
All in the last 2 months (I gave up after 6 months). I couldn't find much before that... out of 563 entries from searching for "inductor power supply".
I keep bees. (Bear with me, you'll see where I'm going with this in a second.) There are two primary magazines for those who keep bees in the US: American Bee Journal and Bee Culture. At one point I had a subscription to both. Now I have neither. Why? Because the magazines keep running the same dozen articles over and over and over and over and over...How to Prevent Swarms, Africanized Honey Bees, How to Find Queens, Things to do With Bee's Wax, and a rather limited number of other topics.
Mind you, I keep bees. I like bees. But I find the repetition to be mind-numbing.
Electronics is a far more varied field. There are lots of things to talk about. It's not necessary to keep recycling the same thread topics. Particularly ideas that have already received the 'bee-treatment,' if I may coin a phrase.
Don't get me wrong...I'm not trying to rain on anyone's parade...it's just that there's this little button that says "Have you searched?"
Perhaps we should petition the Powers That Be to add another button after comes up after the first one that says: "No...really...have you searched?"
Grey
P.S.: Silly me. I didn't know there was a competition to see who could start the most threads.
I must have missed that thread.
Mind you, I keep bees. I like bees. But I find the repetition to be mind-numbing.
Electronics is a far more varied field. There are lots of things to talk about. It's not necessary to keep recycling the same thread topics. Particularly ideas that have already received the 'bee-treatment,' if I may coin a phrase.
Don't get me wrong...I'm not trying to rain on anyone's parade...it's just that there's this little button that says "Have you searched?"
Perhaps we should petition the Powers That Be to add another button after comes up after the first one that says: "No...really...have you searched?"
Grey
P.S.: Silly me. I didn't know there was a competition to see who could start the most threads.
I must have missed that thread.
jarthel said:
Sigh...
This is one of those calculator things, although simple addition with a pencil and a piece of paper will do the trick.
Page 14 of the F4 manual says, "Output device bias is approximately .53 amps per device..."
Since there are three output MOSFETs per rail, this means that the bias will be .53 + .53 + .53 = 1.59 Amps per rail, which is reasonably close to what Zen Mod said earlier. If you want to get picky, the JFETs in the front end will draw a few mA, but then so will the power LED and so forth. The sum total of all of the little things is negligible. Essentially, the current draw of a power amplifier is whatever the output stage draws.
I confess that I'm short on sleep (about three hours last night, four hours the night before), which makes me grumpy, which leads to me being impatient with silly threads...something I try not to do, but I'm human. But please, please, please make an effort before posting. I see a lot of people losing patience with you and I really doubt that everyone here at DIY is short on sleep at the same time.
Not all of the answers are going to be spoon fed to you. You're expected to exert yourself a little bit. The F4 is not a project, per se, it's a commercial product that Nelson is building, even as we speak. As such, the manual isn't laid out as a how-to. You need to use your wits if you intend to build an F4. If you want a more builder-friendly project, consider the Zen or perhaps the A-75 (in my opinion the all-time champion project writeup). Be forewarned, however, that you'll still need to think a bit if you intend to build either of those projects.
Grey
GRollins said:
I like the bee analogy, and I also notice the duplication.
I did start one of these threads (the PI-filter (or CLC vs CRC vs C) one) to ask a specific question. I listed the posts I'd found that didn't answer my question, and Babowana answered it on the first reply. Grey then furthered that a few minutes later. This was really helpful. And, if it was closed at that point it probably would hav emade a useful reference, as after that it was just me whinging a bit about not being able to find any (I did eventually) and some other advice and questions.
A lot of these (seemingly) similar threads seem to devolve into the same questions and answers - like cable threads...
I have searched about using an inductor/choke in a psu within the 'pass labs" section and not many discussions came up.
==============
if you think I have done wrong, report it to the mods I reported off-topic replies to one of my threads and a mod cleaned it.
I guess if your request is reasonable, the mod will act on it
==============
if you think I have done wrong, report it to the mods
I reported off-topic replies to one of my threads and a mod cleaned it.I guess if your request is reasonable, the mod will act on it
Not many came up? How many does it take?
Your attitude isn't illegal or against the rules, but then neither is picking your nose in public. That doesn't mean that it's something a wise man does every day.
The thing that you don't seem to have realized is that this site depends on good will. If your neighbor comes to you asking if he can borrow a hammer, you will probably lend him one. If he comes the next day wanting a screwdriver, you'll probably do that too. But when it's a hammer on Monday, a screwdriver on Tuesday, a drill on Wednesday, a pry bar on Thursday, a sander on Friday, a saw on Saturday, a chisel on Sunday, and on and on and on, you'll eventually ask your neighbor whether he ever intends to buy his own tools.
That's not an unreasonable question to ask.
Grey
Your attitude isn't illegal or against the rules, but then neither is picking your nose in public. That doesn't mean that it's something a wise man does every day.
The thing that you don't seem to have realized is that this site depends on good will. If your neighbor comes to you asking if he can borrow a hammer, you will probably lend him one. If he comes the next day wanting a screwdriver, you'll probably do that too. But when it's a hammer on Monday, a screwdriver on Tuesday, a drill on Wednesday, a pry bar on Thursday, a sander on Friday, a saw on Saturday, a chisel on Sunday, and on and on and on, you'll eventually ask your neighbor whether he ever intends to buy his own tools.
That's not an unreasonable question to ask.
Grey
"But when it's a hammer on Monday, a screwdriver on Tuesday, a drill on Wednesday, a pry bar on Thursday, a sander on Friday, a saw on Saturday, a chisel on Sunday, and on and on and on, you'll eventually ask your neighbor whether he ever intends to buy his own tools."
that neighbor really likes you
that neighbor really likes you
Magura said:
http://www.briangt.com/gallery/magura-inductors
Here you can see some of the tools you need to make exactly such an inductor as I made for Steenoe.
Yes you need a lathe or the like. Something with low revs and quite a bit of power, in order to make the windings lay reasonably even and tight.
The inductors get the shape of the winding-tool, so the tool is the key here.
To make a decent tool will take you a few hours and a nice big chunk of aluminum. Once you have made the tool you can wind the inductors in like half an hour a piece. Again, the tool is the key.
This is naturally depending how big an inductor you have to wind. The big ones from the link, are like a days work to make one.
For 25A you will also have to impregnate the inductors to keep them silent, so a special heat resistant polyesther enamel is a must.
Besides that, all you need is to get some practice, it takes a few attempts to get a reasonable result.
Magura
thanks.
I'll certainly keep you poste on my first attempts
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