How to measure power utilization?

[straius]

Hello everyone,

I have been having strange unidentifiable hardware problems lately and before I go out and buy a bunch of expensive hardware I was wondering if someone could tell me how I can check the power usage in my computer.

Tyan Trinity 400
P3 667MHz
XFX GeForce4 Ti 4200
Sound Blaster Audigy
Delta Omni Studio (Pro Sound Card)
Adaptec SCSI Controller 19160
80Gig ATA100 Hard-Disk
20Gig ATA100 Hard-Disk
18Gig Ultra160 SCSI 10,000RPM Hard-Disk
Creative 56K Modem (Di5630-4)
ACER CD-RW 8x

All of that is on a 300W Power supply and I am worried that my problems might just be due to an inability to give enough power to all my components.

Does anyone know how I can find out if I need a larger Power Supply?

 

[HammerBot]

Unless you have a multimeter that can measure current, its not that easy. Im an electronics engineer and have that kind of equipment lying around and have measured the current consumption on my system once or twice. Anyway, from my point of view a 300W power supply should be enough. But you can check it easily yourself. Pull out some of the devices (e.g. all but your boot HD, the modem and soundcard) and see if your problem disappears.

 

[Hoolio]

you will find it hard to get a multimeter which can measure over 10A.

The supply leads provide about 25A max on the +5v lead. No multimeter can measure that. And my multimeter is one of the top range one, as it cost £300.

Unless you can find an industrial one.

Oh an electronics engineer what do you do?
(I am interested cos that is what I am doing at uni and I am not sure what I will do once I leave uni )

 

[HammerBot]

Right, I know that. And I didnt measure it with and amp-meter. I just stated it for the sake of simplicity. The problem with an amp-meter is also that you have to place it in series with the load (unless you have one of the expensive non-intrusive DC tonque testers). So either you have to cut the power wires or get some mating power connectors so you can extend the wires. Or you you can do as I did: Measure/calculate the resistance of the power wires and then measure the voltage drop across them. This, however requires that you take the power supply apart in order to access each end of the supply wires. This is not recommended since the PSU contains deadly high voltage parts. From the resistance/voltage you can calculate the current. The wire resistance may be difficult to determine accurately, and that sets the precision of the final result. I measured it (with a homebuild low-ohm meter) and then made a quick calculation as sanity check. The two numbers was within 5-10%. If you have a DC current protected powersupply you can get a more accurate result by testing the wires with a current of e.g. 10 Amps and measure the voltage drop as reference.

As far as my occupation is concerned: I work for a biomedical company, where Im involved in the design of equipment for high throughput screening of drugs. Currently Im designing a digital signal processing board that is going to process the data from the drug measurements.

 

[straius]

Hey thanks man, I have a multimeter, but like it was said, I suppose that wouldn't do me any good. Aside from the fact I have no idea where to start with that. hehehe

Thanks though, I'd almost rather spend the money so that the only reason I'm taking hardware out of my comp is because I'm replacing it with something better!. hehehe

Thanks again