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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: bubba on April 21, 2005, 09:26:14 PM

Title: A1200 Power Supply Recommendations
Post by: bubba on April 21, 2005, 09:26:14 PM
I've read alot about power issues with A1200D's using the original power supplies. I'm currently upgrading my A1200D piece by piece and am concerned I will run into power problems soon.  

Can someone make a recommendation for a power supply for my A1200 with the following configuration:

A1200D
Internal 2.5" HD
Internal Floppy
External Floppy
PCMCIA Device (Ethernet or Surf Squirrel)
030/40 mhz accelerator w/32MB

Will the standard A1200 PSU provide enough juice, or should I get an A500 PSU?  If not, what options do I have?

Thanks!
Title: Re: A1200 Power Supply Recommendations
Post by: Harlbro on April 22, 2005, 12:40:46 AM
If you're like me and wish to keep your desktop A1200's original cuteness (i.e. don't want to tower it) but still want to upgrade it a little, the standard PSU is a problem. Once I acquired a 68040/25 accelerator (along with 64Mb RAM, 4Gb 2.5" HDD and 3Com ethernet), the A500 PSU I was using couldn't handle it. I ended up getting my hands on a converted PC PSU. Actually, I have two A500 PSUs but they were both pretty old and needed replacing. So I say get your hands on an old PC AT PSU (<486 or early Pentium) I think are easiest to convert. I know it's pretty simple, does anyone have the instructions (for laymen like me) for converting an PC AT PSU to a standard plug for A500/A1200? I've got two lying here I need to convert.
Title: Re: A1200 Power Supply Recommendations
Post by: adolescent on April 22, 2005, 12:52:12 AM
Montek in Canada sells an inexpensive adapter that converts a PC AT to the A500/A1200/A600.  

http://www.montek.com/cart/product.php?productid=27706&cat=0&page=1


Title: Re: A1200 Power Supply Recommendations
Post by: icbrkr on April 22, 2005, 01:06:53 AM
I'm running close to the same setup and haven't had an issue with the original power supply:

Amiga 1200
68030/50Mhz w/MMU
32MB Fast RAM
6GB Internal drive
Floppy
External Floppy
10 BT PCMCIA NIC

Brian
Title: Re: A1200 Power Supply Recommendations
Post by: blobrana on April 22, 2005, 01:13:39 AM
Hum,
But when you do...
you can always splice one up yourself...

It`s easy, and with only minimal risk of death. Just have a search on google.com for instructions on how to join up a AT pc supply to the amiga, using its own cut lead...

[color=808080]BTW, Anyone notice how  Montek`s site always has 5 users online? [/color]
Title: Re: A1200 Power Supply Recommendations
Post by: Beowulf on April 22, 2005, 01:47:09 AM

Does this powershot adapter come with a case or something you put the power supply in?
Title: Re: A1200 Power Supply Recommendations
Post by: SamuraiCrow on April 22, 2005, 01:56:47 AM
Nah, just run it open-frame.  If you want a tower kit order a tower kit.
Title: Re: A1200 Power Supply Recommendations
Post by: Harlbro on April 22, 2005, 08:10:18 AM
Ahh, this is what I was looking for:
ftp://de.aminet.net/pub/aminet/hard/hack/ExtraPower.lha

This one is only for AT PSUs not ATX. There are other instructions for working on ATX PSUs, of which seem cool cause you can poweroff your machine through software.
Title: Re: A1200 Power Supply Recommendations
Post by: guest1955 on April 22, 2005, 01:00:52 PM
If you want to splice the original PSU up to an AT power supply, this is the way I did it for my 1200.

The 1200 PSU wiring is:
Black = Common
Red   =  5v
Brown = +12v
White = -12v

These were patched into the auxilary power cables on the AT PSU.
From the left of the cable (Blue wire) to the right (Red wire) they matched up as:
Blue  = +12v
Black = -12v
Black = Common
Red   =  5v

Don't forget to use a metre first though.
Title: Re: A1200 Power Supply Recommendations
Post by: blobrana on April 23, 2005, 11:43:14 PM
Hum,
yeah...
Explicit pictures here... (http://mysite.wanadoo-members.co.uk/blobrana/database/amigapower.html)
Title: Re: A1200 Power Supply Recommendations
Post by: XDelusion on May 29, 2005, 09:31:39 PM
---edit--- posted in wrong place
Title: Re: A1200 Power Supply Recommendations
Post by: delshay on May 29, 2005, 10:29:29 PM
@tanletown

@ the AT PSU end you have black= -12 & black = common are you sure?


i done my own conversion useing a pc powersupply,dont remember black being -12v...
Title: Re: A1200 Power Supply Recommendations
Post by: Karlos on May 29, 2005, 10:47:35 PM
Quote

delshay wrote:
@tanletown

@ the AT PSU end you have black= -12 & black = common are you sure?


i done my own conversion useing a pc powersupply,dont remember black being -12v...


-12VDC is blue on every AT / ATX PSU I ever looked at (and I've looked at a few).
Title: Re: A1200 Power Supply Recommendations
Post by: Alma96 on May 30, 2005, 01:07:14 AM
Hello,

For my A1200 with an Apollo 1230/40Mhz accelerator (with a 2.5''HD, an Ethernet card on PCMCIA and a Twister1200 serial card on the clock port), I use a standard A500 PSU and it works fine. If I had to upgrade to a 68040 or 68060, I would go for a PC PSU because the A500 would not do the job.

Title: Re: A1200 Power Supply Recommendations
Post by: blobrana on May 30, 2005, 01:50:32 AM
yellow = +12v
blue = -12v
Black = Common/gnd
Red = 5v
Title: Re: A1200 Power Supply Recommendations
Post by: mattabat on May 30, 2005, 02:45:51 AM
I have a similar setup (except with a 68040 processor running at 40 MHz) and I find that my trusty A500 power brick sees me through fine.
I *did* have a PC PSU but it died due to the dust the thing sucked in.

--
mattabat
Title: Re: A1200 Power Supply Recommendations
Post by: fillosauru on May 31, 2005, 03:32:29 PM
Yea, the PC AT souns pretty good;
I made myself a backup supply for A500 from an old British computer, RM Nimbus power supply;
I don't kow how many watts it suplies, but me A500 works ok with it.
Title: Re: A1200 Power Supply Recommendations
Post by: Bandaid on May 31, 2005, 11:29:23 PM
In a similar situation, I was thinking about upgrading my 65W A500 power supply the other day when I noticed an amazing similarity in size between  it (the hollow A500 type PSW) and a uATX power supply.  Those little guys give you between 200 and 300W!

I don't know if they will supply -12V but a small DC-to-DC converter or even a linear regulator should give you the voltage needed for the Amiga's audio ICs.  You only need ~100mA for -12V anyway.

It looks like it is possible to shoehorn a uATX PSW into the A500/A1200 PSW case. :-D

Unfortunately when I picked up a used uATX supply the other day it was dead (bought at a surplus store)  :-(

Title: Re: A1200 Power Supply Recommendations
Post by: guest1955 on June 12, 2005, 05:25:47 PM
I got a chance to get all my old A1200 stuff out of the loft, so I could check the PSU wiring. I can confirm, after checking with a meter, that on my AT PSU- the blue wire definately does link to the +12V on the Amiga power lead.
Guess this prooves that if anyone intends to work with PSUs, they should definately check with a meter beforehand.