Amiga.org

Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: redrumloa on August 10, 2003, 06:01:23 AM

Title: Amiga 500 power supply, only 34.6W?
Post by: redrumloa on August 10, 2003, 06:01:23 AM
Are my calculations right?

5V  * 4.5A = 22.5W
12V * 1A = 12W
12V * 0.1A = 1.2W
-------------------------
Total = 34.6W?

P=V*I right? Simple right? Right?!?
Title: Re: Amiga 500 power supply, only 34.6W?
Post by: jeffimix on August 10, 2003, 06:27:05 AM
Umm, are these the figures for the wires that come out of the power supply? What kind of power is sent to the motherboard itself (not just HD/CD/floppy power cables)?
Title: Re: Amiga 500 power supply, only 34.6W?
Post by: NeRP on August 10, 2003, 08:14:16 AM
Yeah, I believe you're right.  If I recall, the Amiga 1200's PSU is a
whopping 23.1Watts.
Title: Re: Amiga 500 power supply, only 34.6W?
Post by: Homer on August 10, 2003, 12:08:59 PM
Redrumloa - Yes,
In a DC circuit its as simple as P=V*I with no complications, and the powers are additive as you surmised. What was the reason for this test though ? Were you just shocked how small the power requirements are for the Miggy ? (And how large they are for the PC ??)  :-?
Title: Re: Amiga 500 power supply, only 34.6W?
Post by: PaSha on August 10, 2003, 12:43:18 PM
Quote

redrumloa wrote:
Are my calculations right?

5V  * 4.5A = 22.5W
12V * 1A = 12W
12V * 0.1A = 1.2W
-------------------------
Total = 34.6W?

P=V*I right? Simple right? Right?!?


Well, on my calulator it totals to 35.7 W :)
Anyways, IIRC these are the most powerful A500 powersupplies, the SMPS (switch-mode) kind that weigh next to nothing.
The older ones that are as heavy as a brick, have only 2.5A of +5v, giving a total 25.7 W.

-Paul
Title: Re: Amiga 500 power supply, only 34.6W?
Post by: redrumloa on August 10, 2003, 02:07:07 PM
@jeffimix

This is based on the V and A specification marked on the power supply.

@Homer
I knew it was small, but I have specific reasons to know the exact wattage rating.

@all

Thanks!
Title: Re: Amiga 500 power supply, only 34.6W?
Post by: Lo on August 10, 2003, 06:28:51 PM
Quote
This is based on the V and A specification marked on the power supply

Of course its not constantly using 35 watts?
perhaps using a clamp type AC ammeter on the pwr cord while the
A500 is doing its "secret task"  :-P


Quote
I knew it was small, but I have specific reasons to know the exact wattage rating.


hmmm..Retro gaming center?  A500 rendering farm? :-P
Title: Re: Amiga 500 power supply, only 34.6W?
Post by: redrumloa on August 10, 2003, 06:50:34 PM
Quote
hmmm..Retro gaming center? A500 rendering farm?


It's under NDA, atm :roflmao:
Title: Re: Amiga 500 power supply, only 34.6W?
Post by: Dietmar on August 10, 2003, 07:05:01 PM
>Were you just shocked how small the power requirements are for the Miggy ? (And how large they are for the PC ??)

35W is nice but should have no positive shocking value. To put it into perspective, a basic Pegasos system with HD and low-end graphics card reportedly needs 22-25W. That figure was given for the demo system recently on Giga TV. And even the crazy PC world occasionally comes up with a surprise on this side of 300W. For example, Via's 500MHz m-itx systems only need 5-15W for all electronics, including cpu, ethernet, usb, audio, tv, vga, etc. When I played with a slightly faster variant (EPIA800), I had trouble with the PSU turning itself off because it did not notice the load. Only disabling energy saving and forcing the system to draw more power could keep the PSU interested ;)
Title: Re: Amiga 500 power supply, only 34.6W?
Post by: Athlon on August 11, 2003, 04:01:06 AM
35.7  on mine too
Title: Re: Amiga 500 power supply, only 34.6W?
Post by: jeffimix on August 11, 2003, 04:54:43 AM
/me has a creepy feeling Redrumloa's gonna do something... wierd...
Title: Re: Amiga 500 power supply, only 34.6W?
Post by: Waccoon on August 11, 2003, 05:20:18 AM
Quote
Dietmar:  I had trouble with the PSU turning itself off because it did not notice the load.

Damn, now that's funny!  I used to think only the motherboard could control auto shutoff.

Or maybe it's just a conspiracy to fuel Intel and AMD sales.  :-D