I just did a test of the completed PSU. I used the AS-3220 toroidal transformer. with no load, I'm reading 32V between GND and V+ although specs on the transformer from the manufacturer are are "300VA 20V" is this normal?
Also, it takes several minutes for the caps to drain. I tested R9 and R10 before installation and they are the prescribed 2.2k. Aren't those resistors designed to drain the caps? or is this a normal time period to reduce wasted power while the amp is on? (AS-3220 - 300VA 20V Transformer - AnTek Products Corp)
What's your mains voltage? If you're closer to 120 than 110 - then that seems ok.
re: caps. That's normal. Once you've got your amp boards connected, they'll drain more quickly.
Hi all.
First I apologize for the length of this message.
I've build the PSU which I've realized on diyaudiostore.com board.
I've a transformer which have only one primary at 220V and two secondaries at 24V each (two wires for each secondary therefore four wires in total)
I've a question and for this I link an image that I've found in the forum regarding the scheme of the board.
240 PSU.jpg - Google Drive
In this image, wich showing the scheme of the board, one of the first diode bridge's positive polarity and the negative polarity of the other diode bridge are connect together.
Does this not cause a short circuit? Am I wrong in the reasoning?
Maybe this is avoided by connecting to the AC main electrical ground?
If that were the case, as far as I am concerned and as far as I know it shouldn't be, I don't have an electrical ground in my house and no is possible for me in this moment to connect it, so I think that with this scheme the short circuit is inevitable.
If my reasoning is correct what should I do? Maybe would it be enough for me not to connect the pads in your following images?
https://files.diyaudio.com/archive/g...ium/PSU211.jpg
https://files.diyaudio.com/archive/g...dium/PSU26.jpg
In this case, do you still need to connect the output thermistor (TH1 - connected at the ground connector of the board)? And between what?
Finally I've buyed an AC inlet module wich have two fuses. I've 220V AC main voltage. What value must each of my two fuses have?
Thank you for your time.
First I apologize for the length of this message.
I've build the PSU which I've realized on diyaudiostore.com board.
I've a transformer which have only one primary at 220V and two secondaries at 24V each (two wires for each secondary therefore four wires in total)
I've a question and for this I link an image that I've found in the forum regarding the scheme of the board.
240 PSU.jpg - Google Drive
In this image, wich showing the scheme of the board, one of the first diode bridge's positive polarity and the negative polarity of the other diode bridge are connect together.
Does this not cause a short circuit? Am I wrong in the reasoning?
Maybe this is avoided by connecting to the AC main electrical ground?
If that were the case, as far as I am concerned and as far as I know it shouldn't be, I don't have an electrical ground in my house and no is possible for me in this moment to connect it, so I think that with this scheme the short circuit is inevitable.
If my reasoning is correct what should I do? Maybe would it be enough for me not to connect the pads in your following images?
https://files.diyaudio.com/archive/g...ium/PSU211.jpg
https://files.diyaudio.com/archive/g...dium/PSU26.jpg
In this case, do you still need to connect the output thermistor (TH1 - connected at the ground connector of the board)? And between what?
Finally I've buyed an AC inlet module wich have two fuses. I've 220V AC main voltage. What value must each of my two fuses have?
Thank you for your time.
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Hi,
Where did you get (buy) the PCB ?
I have read the > 110 pages, but I have not found this information, although I confess that I have probably missed it !
Thank you
Where did you get (buy) the PCB ?
I have read the > 110 pages, but I have not found this information, although I confess that I have probably missed it !
Thank you
Hi,
Where did you get (buy) the PCB ?
I have read the > 110 pages, but I have not found this information, although I confess that I have probably missed it !
Thank you
Universal Power Supply – diyAudio Store
There is a problem? What problem are you talking about, I’m missing it or coming into the conversation late...
I am extremely happy with the Universal Power Supply PCB that I bought from the Store and installed in my poweramp. In my opinion the board is great: there is absolutely nothing wrong with it, at all. Never forget: its design goal is universality, as proudly proclaimed in the board name for all to see. The greatest good for the greatest number of people.
If you don't want universality, or if you feel it comes at too great a cost, in terms of part count, board area, circuit complexity, or other criteria ... well then I recommend you obtain or design a different board. diyAudio is a volunteer effort, volunteer your time and expertise to create and publish a PSU which you firmly belive is better. Other members might like it!
If you don't want universality, or if you feel it comes at too great a cost, in terms of part count, board area, circuit complexity, or other criteria ... well then I recommend you obtain or design a different board. diyAudio is a volunteer effort, volunteer your time and expertise to create and publish a PSU which you firmly belive is better. Other members might like it!
Where he asks about the junction of the two bridges causing a short? It does not cause a short, and is normal.
Any bipolar supply is two 0-Vx (in this case, 0-24) power supplies stacked in series, and the place where they connect we call “ground” (or “GND”) and is now the center, because ground is where we want it to be. If we call that point ground, the lower potential point of the first bridge is negative to that GND , and the higher potential point of the second bridge is positive to GND.
Any bipolar supply is two 0-Vx (in this case, 0-24) power supplies stacked in series, and the place where they connect we call “ground” (or “GND”) and is now the center, because ground is where we want it to be. If we call that point ground, the lower potential point of the first bridge is negative to that GND , and the higher potential point of the second bridge is positive to GND.
Where he asks about the junction of the two bridges causing a short? It does not cause a short, and is normal.
Any bipolar supply is two 0-Vx (in this case, 0-24) power supplies stacked in series, and the place where they connect we call “ground” (or “GND”) and is now the center, because ground is where we want it to be. If we call that point ground, the lower potential point of the first bridge is negative to that GND , and the higher potential point of the second bridge is positive to GND.
Ok, thanks 6L6. Just wanted to make sure I did not miss something.
Ya, lest anyone get bad info, this supply kicks *** and is very simple to assemble, I did it. lol
'That PCB has been around for 7yr now with no changes. Many, many amplifiers built using it.
My first four builds used it, it was simple and I never had any issues as a complete newb, it was one of the easiest parts of my build. The thing just freakin works and is pretty damn quite as well. Not SLB quite, but very good.
JT
I thought that would be the case - thanks all!
It's a solid supply SB, if you have questions on your build, just post them here. You do have a current limit device right? It saved my rear for some d-*** mistakes and is a great sanity check... If not, do a search on, "Dim Bulb Tester."
It's just a great way to prevent a simple fk-up... it was the best 8 buck I ever spent. 😀
There is a great crew here to help. If you do a search and get back a phone-book of stuff that doesn't seem to be relevant, back out and do a search from Google. Example: "Dim Bulb and diyaudio" Google seems to be better at getting you to the right place than forum search engines. 🙂
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Yup! Got a dim bulb tester. Just getting a few more parts and ready to go.
If you are unsure, even if you feel, "dim," ask the question, you can't put the smoke back in. I hated asking questions, because I felt stupid asking them, but there's a difference between feeling stupid and being stupid... asking the question and not having a problem= not stupid; not asking the question and burning stuff up=proof of concept stupid. 😎
Hi all.
First I apologize for the length of this message.
I've build the PSU which I've realized on diyaudiostore.com board.
I've a transformer which have only one primary at 220V and two secondaries at 24V each (two wires for each secondary therefore four wires in total)
I've a question and for this I link an image that I've found in the forum regarding the scheme of the board.
In this image, wich showing the scheme of the board, one of the first diode bridge's positive polarity and the negative polarity of the other diode bridge are connect together.
Does this not cause a short circuit? Am I wrong in the reasoning?
Not a short. It's a series connection.
Maybe this is avoided by connecting to the AC main electrical ground?
If that were the case, as far as I am concerned and as far as I know it shouldn't be, I don't have an electrical ground in my house and no is possible for me in this moment to connect it, so I think that with this scheme the short circuit is inevitable.
Mains earth has nothing to do with it.
In this case, do you still need to connect the output thermistor (TH1 - connected at the ground connector of the board)? And between what?
Thermistor between PSU circuit board GND to chassis.
Finally I've buyed an AC inlet module wich have two fuses. I've 220V AC main voltage. What value must each of my two fuses have?
With 220V mains 1.25A. HOWEVER, your country may not allow a fuse on the neutral. You may be able to bypass that depending on the IEC inlet connections. Make sure to follow local AC mains wiring rules and regulations.
Thank you for your time.
Absolutely! Thats what the forum is for.

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