Power needs of an A1200

[Harrison]

We all know that the standard A1200 PSU is a bit weak for much more than a standard A1200 with a ram expansion.

I therefore purchased a Goliath PSU for my A1200 back in the day and it worked perfectly. However it was noisy with the PC PSU fan.

I've recently been running the A1200 with an A500 PSU, which we all know is much stronger and that has been working fine with a setup of A1200 + Ram expansion + 3.5" HD.

However I've now been upgrading the A1200 so was wondering if the A500 PSU will be powerful enough to still work OK with the final setup. It will consist of:


A1200 with 3.1 roms
Blizzard 1230 MK-IV with 32MB ram
40GB 2.5" HD
Buffered IDE interface
laptop CD-Rom drive
PCMCIA network card

And in future I also plan to be adding a Catweasel MK2 plus PC laptop floppy drive.

So will an A500 PSU power that OK? Or should I start using the noisy Goliath again (would consider replacing the PC PSU inside it for a new quiet one).

[Zetr0]

@Harrison

my friend, you are going to need some extra juice!!!!

35 watts is not going to cut it m8.... you will need atleast a good 60 to get that off the ground and remain reliable...

[Harrison]

Thanks. I did think as much.

Although isn't a A500 PSUs rated at 60W? (says it on their cases) Is that right?

Oh, and how much power does a Blizzard 1230 use?

[Zetr0]

@Harrison

I have two A500 PSU boxes, so check yours as one says 60watts the other 35, and the A1200/A600 ones i have are 25 approximately

alas i have no stickers or dates on the plastic :( so I dont know which of the A500 PSU's was made first :(

Now Juice.... Its all how those wonderful watts are provided :) the A500 psu will max out at 5 amps on the +5v (5v * 5amps = 25 watts).... now near enough everything Amiga uses that precious +5v, infact a 1200 mobo with a Blizz 030 on it will sap 4.5 amps.

a 2.5" hard disk.... (old = 500ma 0.5 amps on the +5v) = (0.5*5=2.5 watts) new is around 300ma

a 5.25 ROM will be around 1.5 amps +12/5v pending on manufacture (that can be from 7.25 watts for the +5 model or 18 watts for the 12v model)

obviously writers / burners will use more as will 3.5" hard disks.

LOL i know one guy that expanded his amiga that near enough every time he put a floppy in the drive the whole thing gurued to death LOL.... but that was near enough everything.. an toasty 040/ midi/rom/3.5hdd a crap load of stuff really...

[Harrison]

I've got 4 A500 PSUs. One of them from a very early 1.2 A500 (original style keyboard with C= key) came with a PSU without a watt rating on it, so I have no idea what rating that one is, however it seems much heavier than the others which tends to be a good sign. However the other three PSUs (2 from 1.3 A500s and 1 from 2.04 A500+) all have 60W written on them.

I think I will try the A1200 with the Blizzard, 2.5" HD and CD-Rom, with a 60W A500 PSU and loop an intensive demo to check for stability.

The 2.5" HD is only about 4 years old at most (taken from a broken laptop) so it isn't that old and therefore shouldn't need as much power as an older one, and the CD-Rom isn't really in use that much (I mainly added it as an easy way to update the WHDLoad files on the HD as and when needed).

I will test it all out and see how it goes. Failing that I will just overhaul my old Goliath PSU and utilise that again.

[Harrison]

Got the 1230 Accelerator in the post today so just had to "test" it "quickly". A few hours later :lol: and many games and demos tested I now think I probably do need a stronger PSU. It runs fine with the A500 60W PSU for general things. It boots into Workbench and you can access CDs and launch games and demos. However there are the occassional random sudden system reset for no reason and I think this can only be a power issue.

So tomorrow I'm going to dig out my Goliath PSU and see if it is still working. :)