ACA1232 - Power consumption.

[Coolhand]

I've got an individual computers 1232 030/33 hopefully coming my way in a few days.  I know there may be issues with the card - the timing probs - but I'm mostly concerned that I don't have a heavy duty enough PSU to use it reliably.

All I presently have are the original puny A1200 brick, and one I bought off an internet seller which I'd hoped would be a more powerful A500 brick but turned out to be an equally puny A600 supply.

To be fair, the A600 says 60 watts on the case (and was advertised as such) but apparently according to Ian Stedmans site neither brick can output more than 3 amps on the 5v.

Fully configured the 1200 will be basically stock with CF hard drive and the accellerator.

So does anyone use these weak PSU's with a similar configuration? Am I worrying too much about it - I guess there's an unlikely chance its 'just enough', or should i hack the end of the a600 psu onto an ATX PSU, or is there another option?

Thanks.

[Coolhand]

Thankyou both for the replies.  I looked at that Amigakit PSU (its where I ordered the ACA from - ordered it last night and its being processed today, w00t!), but thats a PC AT/ATX PSU with an amiga cable hacked on by amigakit themselves though?

Because I'm cheap and like to mess with these things I'd perhaps make my own with an old ATX PC supply + the cable off the a600 supply.

I don't really mind it being 'loose' on the floor, its earthed, right?

I'd prefer a neater, silent package though.

If there's a more compact supply that can fit inside the A600 brick (which is even bigger and yellower than the 1200's) and can run silently, safely, in that confined space with no fan that woud be great.

I'm just wondering really what the 1232 might draw from the PSU... Sounds like it might work fine for years based on what 007 is saying - presumably the older the card, the more power hungry - I can't seem to find any figures on what the ACA1232 actually needs?

[Coolhand]

http://ianstedman.co.uk/Amiga/amiga_hacks/Amiga_Power_supplies/amiga_power_supplies.html Ian has posted tables of the power consumption (i'm sure many of you reading this are familiar with it) But I think i read it wrong originally and thought i'd need a lot more than 3amps on the 5v.  so with an ACA 030 the a1200 should need about 2.5amps? leaving me a spare half an amp.... Do the ram chips need a lot more - again i assume you can power a lot more ram with less power these days as opposed to an older card with less memory.

Even if it is adequate, they're old parts and i'm definately interested in making something thats more powerful and efficient, if it can be silent and safe.

[Coolhand]

As another alternative, there's always this:

http://www.amiga.org/gallery/index.php?n=2386

wth is that, antenna cable? I'll pass no judgement on someone elses work but  it's a bit 'whackier' than what i'd thought of hacking together.

really interested in stuffing new psu innards into the old power brick though, keeps it all looking faithfully yellow and nasty... could you fit a pico and a 12v brick inside an old A600 brick?

[Coolhand]

hey whats wrong with bromine brown?

my stock 1200 psu (which along with the machine, i've owned for 20 years) is quite nice and white - never seen a black one... I'm leaving that one untouched and i'm really trying to avoid painting anything or cutting extra holes etc... keeping everything as stealth and as a original looking as possible. so i'm happy to gut the spare 600, yeah retrobrite is something i've looked at... maybe in the summer.

Pico psu seems pretty expensive for me in the UK! For what it is, i could pick up a whole Raspberry pi for as much... then plus the powerpack, isn't there a small low power mains atx power pack for a tiny pc that i could use? one that is low wattage, cheap, requires no active cooling and could be fitted in the chunky a600 brick? wishful thinking i guess;)

[Coolhand]

My ACA1232 along with a real 40GB 2.5" internal HDD is powered from a standard "slimline" amiga 600/1200 powerbrick. The powerbrick hardly gets warm, even after hours of use. If the power supply works and it doesn't get hot, then I don't see a problem. However, I have tried powering that same expanded Amiga with the heavy A600/1200 issue PSU (filled with epoxy like the C64 ones) and the 1200 doesn't even turn on.
Just try it with the PSU you have. If your Amiga works, then great. But, keep your eye on the PSU and make sure it doesn't get hot. If it gets hot then you should find another solution, or get a slimline one like mine (it's the smallest powerbrick that was supplied by Commodore, airey should have one in stock on ebay). All I can tell you is that that particular PSU works like a charm for me.

Paul, did you have to make any timing fixes? I suppose I won't know until I actually start using it, but the 1232s sound like they're a bit more robust in that regard than the earlier ACA's.

Anyway, if the standard PSU works fine for you, again thats re-assuring to know... I doubt my CF needs much power, I have no plans to run any other hardware on there.

I think i have a slimline powerbrick, I'm pretty sure thats the one i had with my 1200, at least its a lot smaller than the A600 one i bought last year... the 1200 was bought in '93.  I stopped using it in favour of the A600, thinking it was superior :whack:

both psu's seem to work perfectly, maybe i'll test them out with the multimeter before installing the ACA... Even if its actually no more powerful its nice to have a backup.

I'm wondering though, how come it says 60 watt on the back of the A600 PSU when according to stedmans site its only 22.2W? is that because its actually drawing 60 but wasting 37.8W?

I guess they made both colors...

There was someone who mounted a micro ATX(including fan) in A500 brick and the result was quite nice. That is why I suggested it. I had acquired a micro ATX OS from somewhere and after seeing that project I was going to do one of my own but I found that the A1200 PS(my black one) is quite a bit smaller than the A500 one used. I don't know if there is a physical size difference between the A600 and A500 bricks.

I also read an article (perhaps Tomsharware) where someone removed the fans from PC PS and they were still able to operate reliably without a fan. I don't know if this due to the fact that CPU fans provide enough airflow through the case.

I once had a 486 computer that I used to run some satellite equipment. I removed the fan from the PS and ran it that way for years....

I guess it just depends on the power you're actually using, I'd carry out a lot of testing to see how hot its really getting with and without the fan! I'd be concerned about something like that overheating in the small plastic case... even bundling a modern 12v brick and pico psu in one.  eh I guess there's no ideal solution, seems like with what Paul and yourself are saying, I can manage with what I have so far.

btw, outstanding service from Amigakit so far, my items have now been 'delivered' according to their website and I can track them on royal mail - only placed the order 24 hours ago.:banana:

[Coolhand]

Yes, mine was a revision 2B A1200 motherboard, so it needed fixes (very simple to do mind).
I have the chunkier Amiga PSU's as well, but the ones I have run too warm for my liking, so I stick with my slimlines.

I have a very very beefed up A1200 that's also running off of a standard PSU!

As for the 60 watts rating, for a guess that'll be the overall power consumption of the PSU when driving it's maximum rated loads. Remember, PSU's aren't 100% efficient... far from it. Some are very bad.

is that 60 watts from the wall? according to stedman the max is 22.5... I'm thinking it can supply 22.5 max to the computer as various DC voltages, but needs 60 watts to make that DC power from the mains!

Also a lot of waste heat to dump out at full tilt, never noticed a large amount of heat coming from either brick so far.

2B, Thats the same revision as mine... sorry for all the q's but did you have to do the whole works on it http://eab.abime.net/showthread.php?p=753433#post753433 or just remove the couple of caps on the back? maybe i should order some components and warm up the soldering iron... guess I need to replace the caps too, what have I got myself into?:roflmao:

[Coolhand]

My A1200 was a NOS from Amigakit like 3-4 years ago.

Its a 1D4 and I took the MB to do a different MB fix for multiscan artifacts and at that point I inspected to see if I needed the timing fix and it did not. It did not look like those components were ever populated... so not all need timing fixes.

I run with Blizz1260.

I've had the thing apart a lot of times, it needed a lot cleaning when I decided to start to ressurect it a couple of years ago - I've replaced the keyboard membrane (half the keys didn't work) and modded a pc floppy to replace the knackered chinon thanks to some walkthroughs i found online. Anyway one time I looked at that area and it does have those infamous capacitors and resistors, but I'm not going to touch it until i know whether its having probs or not. So far i haven't found anyone with a 2b who has had no issues so i'm anticipating doing some work on it, all part of the err, fun.

[Coolhand]

Yes, that particular PSU must be very inefficient.

I haven't checked but I guess my original power pack - the later compact one - provides the same power but perhaps uses less power from the wall to do that.

As for the fixes, I just pulled off (they disintegrated) the two tiny capacitors with needle-nose pliers. Soldering iron not needed! I tell ya...it was the best de-soldering job I had ever done... you wouldn't even know that those components were ever there, as it just looks so bloody neat.

Call me crazy but I might do it the old fashioned way... Dremel...

must get some decent solder wick - got some cheap stuff but its useless.  

Either way, if that's all I have to do I'll be a happy bunny... i've seen pics of mod wire going here and there and talk of ferrite beads and resistors. Less I have to mess with it the better.  

The next job will be to replace all the electrolytic caps...  I probably won't wrench those off with pliers tho;)

[Coolhand]

as a follow up on this thrilling thread, I dug out the slim psu, same model number as the phat yellow supply. marked for A600 again (this was the one that came bundled with my desktop dynamite 1200) but the power is rated at 25watts... Which was what lead me to believe the 60 watt was better/more powerful.  

Of course I checked the wrong thing when i bought it and the DC output on the 25 is exactly the same as the 60watt supply, just as Ian Stedmans site suggests.  

So clearly there's a big improvement in efficiency between the two... I'll go back to using the slimline and keep the nasty browny yellow, inefficient one for a mod or a backup.  Presumably because one is so much more efficient - yet they were probably manufactured within a year or two of each other - one is linear and one is switchmode?

[Coolhand]

I'm pretty sure the original A1200 PSU was 30 watts. The 68040 uses 15Watts exactly, so maybe it was a 15 watt psu.
Check the specs for a 68030. You can calculate the voltage x megahertz (5 volts?). The card and the RAM would be no concern at all.

Put in a bigger PSU if you can afford it, the system might run a bit smoother when you add hard drives and accessories.

if it needs 15 watts of power and runs on 5v then thats using 3 amps of power... So your 040 alone is maxing out the standard 1200 +5 rail.

030's use a lot less juice... but then they're more similar to the 020 than the 040...  When I read the figures on Stedman's site I was reading the combined A1200 + Accelerator as the value for the accelerator alone.

Though i'm not worried based on what people (thanks Coltch) are saying its odd that I can't find the max power consumption figures for the ACA. Are they a secret or am I just not looking hard enough?

I agree even though its enough, a slightly more powerful supply would be desirable, especially a modern supply... I just dont think the Pico is worth it for the money, I can't find a supplier with reasonable prices here, when its still not really ideal and needs work to house it etc.... Modding a low power ATX seems like the only option really if you need the power. Surprising that no one is producing dedicated modern Amiga PSU's though.

[Coolhand]

If you mean the timing issues, as I understand it, its random even within the same PCB revision because the specific components used could be different - presumably depending on what commodore could source. I'll soon find out whats what, board arrived today I think (it says delivered on the RM tracking site) but I haven't been home to fit it yet.

[Coolhand]

So I got the card and installed, with many 2d games its crash city as expected.

Dremelled off the two caps on the back of the board (actually carefully de-soldered and cleaned up with chem-wick - awesome stuff)

It's slightly better but not reliable at all with about half the titles i tried, It absolutely hates anything by bullfrog for example... I guess I will have to try and source the correct parts and make the rest of the alterations, hope that fixes it up better.  Kinda crappy that there's not a definitive guide, seems I have to combine the advice on Ian Stedmans site with the instructions from Jen's... I'll probably raise a support ticket with Amigakit and see what they advise.

edit: hmmm, maybe I spoke too soon, only thing thats actually crashed it at this point is Theme Park, syndicate runs great, very smooth played through 4 missions with no issues, just removing those 2 caps has made a massive improvement!