POLL:Does a 350Watt PSU use more than 10Amps?

wedi42

Platinum Member
Jun 9, 2001
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someone will know the math, but i know that 1500 watts is not more than 20 amps
so 350 watts can not be more than 10 amps
more like 5 amps
 

Scootin159

Diamond Member
Apr 17, 2001
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I'm assuming you're talking @ 110/120 volts?

If so:

350W / 115V = 3.04A

EDIT: Also remember that is 350w MAX, it's not always drawing 350w.
 

Jerboy

Banned
Oct 27, 2001
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How about "inadequate information" option?

wattage is function of voltage, current and also power factor in an AC circuit and you missed out one or two factors, therefore it is not possible to come up with the answer.

An electronic ballast(which is basically a PSU) with input of 350W driving total of 310W in fluorescent lamps at input voltage of 277V(common on commercial 480V Wye three phase supply) AC and has power factor of 0.95, the effective input current is 1.33A


This is not General Hardware, so I'm assuming you're not necessarily talking about standard computer power supply.
 

Evadman

Administrator Emeritus<br>Elite Member
Feb 18, 2001
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More info is needed! :D As you can probably tell.
 

Jerboy

Banned
Oct 27, 2001
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Hey my load draws 19.2A and it's only 230W..

Oh wait.. that's the blower motor in my car..
 

Legendary

Diamond Member
Jan 22, 2002
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Vi = P
V = voltage (110/220) I = current (A) P = Power (350 Watts)
I thought we had all the info...but then again...I'm not a physicist :D
 

Jerboy

Banned
Oct 27, 2001
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<< Vi = P
V = voltage (110/220) I = current (A) P = Power (350 Watts)
I thought we had all the info...but then again...I'm not a physicist :D
>>



Direct current circuit:

P=VI, assume duty cycle is 100%, otherwise P=VI x duty cycle

AC circuit:

P=V I x PF

He mentioned I, missing out both V and PF, therefore one can only pull numbers out of their ass.
 

N8Magic

Lifer
Dec 12, 2000
11,624
1
81


<< How about "inadequate information" option?

wattage is function of voltage, current and also power factor in an AC circuit and you missed out one or two factors, therefore it is not possible to come up with the answer.

An electronic ballast(which is basically a PSU) with input of 350W driving total of 310W in fluorescent lamps at input voltage of 277V(common on commercial 480V Wye three phase supply) AC and has power factor of 0.95, the effective input current is 1.33A


This is not General Hardware, so I'm assuming you're not necessarily talking about standard computer power supply.
>>



rolleye.gif


I think he was talking about a computer PSU. Most people don't have commercial hookups in their room/office.
 

Jerboy

Banned
Oct 27, 2001
5,190
0
0


<<

<< How about "inadequate information" option?

wattage is function of voltage, current and also power factor in an AC circuit and you missed out one or two factors, therefore it is not possible to come up with the answer.

An electronic ballast(which is basically a PSU) with input of 350W driving total of 310W in fluorescent lamps at input voltage of 277V(common on commercial 480V Wye three phase supply) AC and has power factor of 0.95, the effective input current is 1.33A


This is not General Hardware, so I'm assuming you're not necessarily talking about standard computer power supply.
>>



rolleye.gif


I think he was talking about a computer PSU. Most people don't have commercial hookups in their room/office.
>>



Well then let's see...

a good assumed PF=0.75, good assumed efficiency=70%

350/0.75=466.7W
466.7/.7=666.7VA

VA/V rms=A rms

if AC=240V: 2.9A
if AC=120V: 5.5A
if AC=100V: 6.7A


*assuming current draw is sinusoidal and the PSU is loaded to 350W.