How to find wattage of this external SCSI power supply?

computer

Platinum Member
Nov 5, 2000
2,735
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Guys, I have this external case and power supply (see below). I forgot I had it and guess I can use it for my external 5.25" bay and external power supply (from another post). The problem is I can't find what the wattage is of the power supply in it. The sticker states "100/240VAC 2.0A" which Ohm's Law tells me it would be 200 watts @100v, and 230 watts @115v. This sounds like a lot for just a SCSI HD, although it is one of those massive 10lb full height boat anchors. I don't know if I should go by that sticker, and THAT figure is the REAL wattage, or take readings from the 12v and 5v lines and go by them. 12v is 4.2A and 5V is .8A which is only 50 watts on the 12V line. So, is this a 50 watt PS or 200 watt PS?

I wanted to use the PS to power some devices since I think my PC"s main PS is going to be choked a bit. This device would be great since I can't find any external AT PS enclosures and I need an external 5.25" bay anyway for an audio EQ.

Here and here are some images and I pasted the info they give below:

** External 9.0GB SCSI Hard Drive **

- Drive Model Seagate ST410800N
- Formatted Capacity of 9,090 MegaBytes
- Internal Transfer Rate 44-65 mbits/sec
- External Burst Transfer Rate of 10 mbyte/sec
- 5400 rpm Spindle Speed
- 5.5 ms Average Latency
- 1024 Kbyte Read Look-Ahead, Adaptive, Multi-Segmented Cache Buffer
- 11ms Average Access Time

- Preinstalled into a ROCK SOLID External SCSI Case
- Selectible SCSI ID
- Heavy Duty Fan
- Case is UL, CSA and TUV approved
- External Connector is HD (High Density) 50 (aka: Micro DB50 - Female) w/passthrough
- Case size is 13 x 9.25 x 5.5 inches (L x W x H)
- PC and MAC Compatible
- NEW (case) and Refurbished (Drive), w/power cord
- External Case has NO FACE-PLATE BEZELS


High-Capacity, High-Performance, Full-Height
Narrow SCSI-2 disk drive with 9.09GB of
formatted capacity, PRE-INSTALLED into a high
quality External SCSI Case!!!

Thanks.
 

Zepper

Elite Member
May 1, 2001
18,998
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That drive's a monster, does it rock like a washing machine with a full tub when it starts all those platters moving?
. Power supplies are rated by their output, so it's about a 50 Watt power supply. If it's a switching PSU then it will be drawing 75W or so from the wall at full load. If it is an old-style, linear PSU, then at least double the AC draw. What it draws from the wall is irrelevant to the output power - I just threw it in FYI.
.bh.
 

computer

Platinum Member
Nov 5, 2000
2,735
2
0
Originally posted by: Zepper
That drive's a monster, does it rock like a washing machine with a full tub when it starts all those platters moving?
. Power supplies are rated by their output, so it's about a 50 Watt power supply. If it's a switching PSU then it will be drawing 75W or so from the wall at full load. If it is an old-style, linear PSU, then at least double the AC draw. What it draws from the wall is irrelevant to the output power - I just threw it in FYI.
.bh.
Probably! But I never even powered up the HD. It can certainly be used to anchor an aircraft carrier. I learned more about it, see this thread:
http://forums.anandtech.com/messageview.cfm?catid=27&threadid=1299835

It's not 50 or 54 watts going by the Amp readings on the line because they are identical on a 300 watt ATX and a 250 watt AT. I'm not saying it's NOT 54 watts, it might be. I'm just saying that those current readings of .8 and 4A I mentioned in the original post are not what determines its wattage.
 

Zepper

Elite Member
May 1, 2001
18,998
0
0
Yes, the power rating of a power supply is the total output power. On most ATX PSUs the output rating is less than the sum of the VxA of the different rails because several rails share a winding off the transformer (the 3.3 and 5V rails). In the case of a dual voltage supply, the output power can be taken as the sum ot the VxA of the rails becaluse there is no sharing of windings.
.bh.