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

[Mounty]

Originally Posted by Retrofan

Yes, two seconds to find them http://www.vesalia.de/r50e_amiga_har...pare_parts.htm

It would be nice if you could make a Mechy Apower style PSU.

To make it unbeatable it would have to add the 5v sensor in the power connector to supply exactly that.

Two seconds to find them and another two seconds to reject them.
That is not a place where developers buy components. It is for the general public who just buy one or two units. If that turned out to be the only option I would drop the project immediately, as it would no longer be economically viable.

I'm not sure what a Mechy Apower style PSU is, but I'm guessing it is an enclosure that at these miniscule volumes would cost me more per unit to make than the end user would pay for the entire power supply.

The mechanism for ensuring exactly 5V is called regulation. This is normally performed by pulse width modulation, which is what I would be using.

[Predseda]

Originally Posted by Mounty

I may have a supplier for this connector, but if that does not happen, then the buyer would need to transfer the cable from his broken psu.

This is very unhappy situation. I would like to buy several complete PSUs for my Amigas that dont have any, not as a replacement, but as spare ones. If I have to kill one to get another one working, it is not a solution for me.

[cpiac64]

you need create 5V 5A for amiga with espansion
12V 2A and -12V 0,1A

if you need square connector, i have 4 nos black

[BarryB]

Talking of ampage, will it cope with extra stuff installed like an accelerator (Blizzard 1230 or BPPC in A1200), indi ECS/AGA, USB, A1200 PCMCIA card, up to 3 external floppy drives etc?

[Mounty]

Originally Posted by Predseda

This is very unhappy situation. I would like to buy several complete PSUs for my Amigas that dont have any, not as a replacement, but as spare ones. If I have to kill one to get another one working, it is not a solution for me.

Nbody is suggesting you "kill" a good one. The idea is you take a cable from a faulty psu.

Originally Posted by cpiac64

you need create 5V 5A for amiga with espansion
12V 2A and -12V 0,1A

if you need square connector, i have 5 nos black

I'm not sure I want to create a super-powerful psu. You can go down the ATX PSU route if you want that. I was thinking of a low cost direct replacement.

Originally Posted by BarryB

Talking of ampage, will it cope with extra stuff installed like an accelerator (Blizzard 1230 or BPPC in A1200), indi ECS/AGA, USB, A1200 PCMCIA card, up to 3 external floppy drives etc?

No.

[cpiac64]

some original psu are 4,5 A on 5 volt

[Mounty]

Originally Posted by cpiac64

some original psu are 4,5 A on 5 volt

Yes, but most weren't.

As usual, I'm not going to bust a gut trying to appeal to absolutely everyone.

Most people will suffice.

[Vot]

Aren't people just using pcio psu's these days (the genuine ones are good), non genuine are rubbish however

[Retrofan]

Originally Posted by Mounty

I'm not sure what a Mechy Apower style PSU is.

http://www.amiga.org/forums/showthread.php?t=57275

http://www.amiga.org/forums/attachme...1&d=1302220256

[Predseda]

Originally Posted by Mounty

Nbody is suggesting you "kill" a good one. The idea is you take a cable from a faulty psu.

But you know - I need additional new PSUs. That means I would need to buy some faulty ones - or connectors - because of it. If you are able to develop a cheap complete SMALL Amiga PSU, I will buy it. I am fed up with bricks.

[Mounty]

Originally Posted by Vot

Aren't people just using pcio psu's these days (the genuine ones are good), non genuine are rubbish however

Yes, but that's because there's nothing much else out there.

Originally Posted by Retrofan

http://www.amiga.org/forums/showthread.php?t=57275

http://www.amiga.org/forums/attachme...1&d=1302220256

Thanks.

Originally Posted by Predseda

But you know - I need additional new PSUs. That means I would need to buy some faulty ones - or connectors - because of it. If you are able to develop a cheap complete SMALL Amiga PSU, I will buy it. I am fed up with bricks.

That's the idea. But we may have to be flexible regarding connectors.

[BarryB]

Be much easier if they had used a round 5 pin din for socket/plug, would have saved a lot of messing about. Just wondering if there is a 5 pin round socket that will fit the same pinout?

[Mounty]

Originally Posted by BarryB

Be much easier if they had used a round 5 pin din for socket/plug, would have saved a lot of messing about. Just wondering if there is a 5 pin round socket that will fit the same pinout?

Even if you could find a round plug with properly aligned pins, the body of the plug would prevent the connectors from mating properly.

For those who can use a soldering iron, with a little imagination you could cut the connector off and install almost any right-angled connector you wanted.

Or you could attach something like this:

[Mounty]

Originally Posted by BarryB

If no C64 support, build one separate. A few members have looked into making one, even Jens, but no one so far has done it and released one

As for the square plug, it was made by Mouser Electronics, Stock No. 171-4405

Maybe there wasn't much of a demand for a C64 PSU. That would put most developers off.

[Daedalus]

Yep, a 5-pin round DIN connector would most likely be a drop-in (solder-in) replacement for the existing connector. The only problem might be someone trying to use an incompatible PSU and frying something - C64 or Atari XL for example.

[hooverphonique]

Originally Posted by Retrofan

No idea about the -12v line, but I need exactly 5volts delivered to the psu plug of the Amiga. Jens was going to put a sensor there to control it.

that's just a matter of connecting the sense line to the power connector that plugs into the amiga. Requires an additional (thin) wire in the cable, though..

[Mounty]

Originally Posted by hooverphonique

that's just a matter of connecting the sense line to the power connector that plugs into the amiga. Requires an additional (thin) wire in the cable, though..

Nothing is exact in electronics. There is always a tolerance.

The Amiga will accept a few mV either side of 5V. A decent regulator will take care of that.

[john1979]

Originally Posted by Akira

You also need 12 or 9V AC for a C64 (12V for old ones, 9V for new ones). I wouldn't bother trying.

Both old and new need 9V AC.

Originally Posted by Mounty

Maybe there wasn't much of a demand for a C64 PSU. That would put most developers off.

The demand is massive. Look at the huge amount of PSU threads on Lemon64, or the many replies to Kipper2k's thread (which came to nothing, and he can't even be bothered to reply in that thread now.) The C64 PSU was so incredibly bad that almost everyone looks to replace it when they get a 64.

[Mounty]

Originally Posted by john1979

Both old and new need 9V AC.



The demand is massive. Look at the huge amount of PSU threads on Lemon64, or the many replies to Kipper2k's thread (which came to nothing, and he can't even be bothered to reply in that thread now.) The C64 PSU was so incredibly bad that almost everyone looks to replace it when they get a 64.

Was was so bad about it?

[john1979]

Originally Posted by Mounty

Was was so bad about it?

They get hot and slowly cook themselves. To make it worse some are filled with epoxy trapping the heat in even more. When they fail they usually send around 12v down the 5v rail and kill the C64. To make it even worse again, people tend to assume the C64 is broken and not think about the PSU, so they plug it into a another C64 and kill that one as well.

They are ticking time bombs.