Developing a new A500/1200/600 power supply. -12V needed?

[Retrofan]

Arnie I'm not an electrician and I don't like the idea of frying things

Edit BarryB your first link is perfect, I like it.

[Arnie]

LOL, well maybe not you, but someone could help you

[Mounty]

Originally Posted by Retrofan

Mounty I only need a PSU that delivers 5 volts to the Amiga socket. I only receive there 4.6 or around, I don't remember. Let's see, my ATX outputs 4,9 volts (I've got a led screen showing that), and there are 2 meters of not so thick cable connecting later to a bad amiga psu socket.

You also won't need much watts in the psu, only the ripple is important. http://eab.abime.net/showthread.php?...ope#post837066


.

Not just 5 volts.

Also 12 volts and minus 12 volts.

[Retrofan]

Yes, I know. I talk about the important part:

Originally Posted by Schoenfeld

ATX PSUs don't treat the 5V rail as a critical line. Regulation on that rail is average, but not good enough to maintain stable operation of a computer that is 5V-based.

Jens

[Yakumo9275]

for a c64 psu, last time I looked around, was hard to find a nice tranny that you could tap off 9VAC from one or two taps here in the usa. I remember finding some rated at 220 but not for usa 110. I ended up hacking a tranny out of a 9vac walwart (good for a one off, no point if you need more than one!)

[Mounty]

Originally Posted by Retrofan

Yes, I know. I talk about the important part:


Originally Posted by Schoenfeld View Post
ATX PSUs don't treat the 5V rail as a critical line. Regulation on that rail is average, but not good enough to maintain stable operation of a computer that is 5V-based.

Jens

There are a lot of people using ATX power supplies with their Amigas. They are the people to listen to. What are they saying? Do their experiences agree with Jen's statement?

It is very important that the 5V is accurate, because hard drives use it, and they need an accurate supply just like a computer does.

These days, with accurate components becoming very cheap, it is relatively easy to get close to 5V.

[BarryB]

Plus, Amigakit sell an ATX PSU that's been modified for the Amiga, so are they wrong or have they done something to the 5v rail? I have one in my A1200 and that powers a Mediator/Sound Card/Graphics Card/Blizzard PPC/2 floppy drives/Indi AGA mk2/Dual CF Card/140mm 12v Case Fan and have had no issues.

[Lord Aga]

Originally Posted by BarryB

Plus, Amigakit sell an ATX PSU that's been modified for the Amiga

They do ?
Linky dinky pretty please.

[Arnie]

Originally Posted by BarryB

Plus, Amigakit sell an ATX PSU that's been modified for the Amiga, so are they wrong or have they done something to the 5v rail? I have one in my A1200 and that powers a Mediator/Sound Card/Graphics Card/Blizzard PPC/2 floppy drives/Indi AGA mk2/Dual CF Card/140mm 12v Case Fan and have had no issues.

Tower version only?

[BarryB]

Originally Posted by Lord Aga

They do ?
Linky dinky pretty please.

Originally Posted by Arnie

Tower version only?

Not looked since I bought mine but they only have the one for Towered A1200s at the moment! The one I bought had rubber feet so it could sit on a desk and had an option for the Amiga connector only or leaving the original molex/floppy connectors, I had the one with all the connectors still attached as I wanted to power a CD/DVD drive and connect to a Mediator.

This is the page, but not currently live: http://amigakit.leamancomputing.com/...roducts_id=866

[Amiga1992]

Originally Posted by BarryB

Plus, Amigakit sell an ATX PSU that's been modified for the Amiga, so are they wrong or have they done something to the 5v rail?

This is the first time i hear of this, then again I don't have a tower Amiga with a Mediator or something power hungry like that. My 030@50 setup works great with a picoPSU.

[BarryB]

Perhaps Mounty should just buy cheap ATX PSUs, put them in a new case with an Amiga connector grafted in and sell them for 3x the price

[cpiac64]

i have a c64 psu made in italy, verify schematics and add soon

[Retrofan]

What is necessary having an ATX PSU to use a sensor and rectify the delivered 5 volts? Any link explaining that? Any kit? I'm thinking in adding it to one of my ATX's PSUs. Well, at least I'm curious.

[thgill]

Originally Posted by Arnie

So what's wrong with Ray's psu, not reliable enough or too expensive or both?

Nothing is wrong with Ray's PSU design. It's actually quite well built with both 9v AC and 5v DC protection.

I did a mini review and taking apart of Ray's C64 psu a couple weeks ago:

[ Show youtube player ]


Considering I am in the US, mine only cost about $105 shipped. It was certainly worth the money.

[Lord Aga]

Originally Posted by BarryB

This is the page, but not currently live: http://amigakit.leamancomputing.com/...roducts_id=866

Yes, this has been dead for quite some time. So it is more accurate to say that they don't sell Amiga PSUs.

Looks like Obi Van Mounty is our only hope

[Mounty]

Originally Posted by Lord Aga

Yes, this has been dead for quite some time. So it is more accurate to say that they don't sell Amiga PSUs.

Looks like Obi Van Mounty is our only hope

These are not the droids you are looking for...

Er AHEM! Sorry..

I was studying the schematics last night and I reckon I could put a C64 power supply together for less than 10 quid. Probably not in a nice neat package for selling but it should work fine.

9V ac and 5V regulated. Not exactly rocket science. It's when it gets inside the C64 it turns into a dog's breakfast. I mean, two seperate 5V rails?? What's all that about?

[Kehil]

Originally Posted by Mounty

There are a lot of people using ATX power supplies with their Amigas. They are the people to listen to. What are they saying? Do their experiences agree with Jen's statement?

Jens statement does not say that there is no ATX power supply working with Amiga well. Difference between good and bad (budget) one will surface with expansions connected to the system.

http://eab.abime.net/showpost.php?p=1014340&postcount=268

[Retrofan]

Originally Posted by Mounty

These are not the droids you are looking for...

Er AHEM! Sorry..

I was studying the schematics last night and I reckon I could put a C64 power supply together for less than 10 quid. Probably not in a nice neat package for selling but it should work fine.

9V ac and 5V regulated. Not exactly rocket science. It's when it gets inside the C64 it turns into a dog's breakfast. I mean, two seperate 5V rails?? What's all that about?

Don't worry about the "nice neat package"; I've got an empty C64 (epoxy kind) PSU awaiting for something inside...

[Mounty]

Originally Posted by Kehil

Jens statement does not say that there is no ATX power supply working with Amiga well. Difference between good and bad (budget) one will surface with expansions connected to the system.

http://eab.abime.net/showpost.php?p=1014340&postcount=268

Of course. That is obvious. Push a low quality item hard and it's more likely to fail than a high quality item.

Myself, I don't really want to get involved with high current PSUs.