Feeding an A1200 from 2 different PSUs. Is it safe?.
  • Order of the Butterfly
    Order of the Butterfly
    AmigaMancer
    Posts: 265 from 2005/8/25
    Hi.
    I haven't towerize my Amiga 1200 and i'm only using a A500 PSU to feed the motherboard. (plugged in the power connector of course) My hard disks and CD drive are hosted into a simple pc tower and powered from the PSU of this tower.
    The A500 PSU seems powerful enough, as both the 68k and the PPC side (WOS, PUP) in AOS3 are rock stable, but i'm having some stability issues with MorphOS. I'm not sure of what causes this issues in MOS but i want to try to plug a power cable from the PC PSU of that tower, to the disk-drive plug of the mobo and see if this improves things.

    So... i will have a A500 PSU plugged in the power plug of my Amiga and a PC PSU plugged in the disk-drive.
    Hmm, Is this safe? If it is, in which order should i switch on and off the PSUs?
    I need some responsible feedback on this because i don't want to burn my rare and precious hardware. :-D
    Amiga 1200 user.
  • »12.04.07 - 18:30
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  • Order of the Butterfly
    Order of the Butterfly
    merko
    Posts: 328 from 2003/5/19
    I'm definitely no expert on this, but I have a vague feeling it is not
    a good idea. Powering the drives etc from another PSU should be fine,
    but I suspect there might be weird and unexpected side effects if you
    plug in two of them in the same circuits.
  • »12.04.07 - 18:48
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  • Cocoon
    Cocoon
    Madgun68
    Posts: 60 from 2003/4/16
    From: Spokane, Washi...
    That is not really a safe idea. Don't risk your Amiga on something like this.

    You should be able to test it well enough with AOS3. Put the ppc under as much cpu load as possible and see if everything is still stable. (DNETC is a good place to start if you aren't running it already.)

    There are several things it could be.. (Power supply, heat related..) Or maybe something is up with MorphOS.
  • »12.04.07 - 19:14
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  • Acolyte of the Butterfly
    Acolyte of the Butterfly
    Kamul
    Posts: 121 from 2004/6/9
    From: Poland, Katowice
    I wouldn't do that. If voltages of these two power supplies are
    different (and for sure they are - at least a little), there will flow
    quite big currents by your main board wires.

    By the way, why don't you get rid of A500 PSU and simply connect pc
    PSU to A1200 power connector?
  • »12.04.07 - 19:27
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  • Order of the Butterfly
    Order of the Butterfly
    AmigaMancer
    Posts: 265 from 2005/8/25
    Thank you for the warnings guys. I won't dare it.


    @Madgun68
    Quote:

    You should be able to test it well enough with AOS3. Put the ppc under as much cpu load as possible and see if everything is still stable. (DNETC is a good place to start if you aren't running it already.)

    I haven't found a WOS/PUP version of DNET but i do have tested my system with high PPC CPU load under AOS3 and it's stable.
    Amiga 1200 user.
  • »12.04.07 - 19:44
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  • Order of the Butterfly
    Order of the Butterfly
    Wishmaster
    Posts: 342 from 2003/6/29
    Have a look here for DNet.

    http://distributed.amiga.org/
    Pegasos PPC
  • »12.04.07 - 20:45
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  • Priest of the Order of the Butterfly
    Priest of the Order of the Butterfly
    MarK
    Posts: 641 from 2004/1/25
    From: Prague, The Cz...
    i have made already two pc psus working with amiga... it's simple, you just need a multimeter, solder and some small intelligence :-) Measure all of the pins that supplies your amiga of the amiga psu, you should get some gnd, +12, -12, +5 and -5 Volts (i hope so... just don't remember exactly), then cut the Amiga cable near to the psu, release all those wires, and mark, which one brings to amiga what...
    then open the pc psu, and find where are all those needed poweroutputs, and solder there your wires from the amiga cable... that's all... now you have a strong pc psu with amiga cable, and that should be enough... for every amiga configuration :-)

    bye, MarK.

    ps: i could do it for you, if you would send it to me ;-)

    [ Edited by MarK on 2007/4/13 6:26 ]
  • »13.04.07 - 05:25
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  • Order of the Butterfly
    Order of the Butterfly
    AmigaMancer
    Posts: 265 from 2005/8/25
    @Wishmaster
    Quote:

    Have a look here for DNet.

    http://distributed.amiga.org/

    Ok, got it.


    @Mark
    Quote:

    ps: i could do it for you, if you would send it to me

    :-D Thanks, but your instructions made it easy enough ;-)

    [ Edited by AmigaMancer on 2007/4/13 18:31 ]
    Amiga 1200 user.
  • »13.04.07 - 16:30
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  • Butterfly
    Butterfly
    Get27
    Posts: 90 from 2004/8/23
    From: Vinzelles, France
    Hi !
    Use 2 PSU is very dangerous !
    If the Amiga PSU do not start, you send power to "data" pins of components without power them.

    For a unique PSU, let's have a look here :
    http://amigaga.chez-alice.fr/classic/bidouilles/alimentation/alimpcatamiga.htm

    [ Edited by Get27 on 2007/7/15 12:14 ]
    PowerMac 3.5, G4 1.0GHz DP, 1GB ram, 80GB HD + NAS, Radeon 9600 128MB Mac, 1680x1050
    PowerMac 7.3, G5 2.3GHz DP, 4GB ram, 160GB HD + NAS, Radeon 9800 128MB PC, 1680x1050
    Amiga 500+, Vampire 500v2+, HxC Floppy
  • »15.04.07 - 12:02
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  • Moderator
    Doraemon
    Posts: 137 from 2003/7/1
    From: Calella Republ...
    I literally burned one A1200, the 1200 PSU and a AT psu doing that a lot time ago.
    Do not make it!
    Its really dangerous!
  • »15.04.07 - 13:05
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  • Order of the Butterfly
    Order of the Butterfly
    AmigaMancer
    Posts: 265 from 2005/8/25
    Wow! 3 devices in a row.. Thanks for the warning.
    Amiga 1200 user.
  • »15.04.07 - 20:55
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