The HP Pavilion w1907, 19 inch Widescreen monitor, RK283AA,
uses 49 Watts in operating mode, 2 watts in sleep mode.http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00916924&tmp_task=prodinfoCategory&cc=us&dlc=en&lc=en&product=3351967
The Compaq Presario SR5410F Desktop PC, has a 250 Watt power supply. (Maximum wattage rating )http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01374067&tmp_task=prodinfoCategory&cc=us&dlc=en&lc=en&product=3686678
Back in the day when this computer was made, Power Supply manufacturers were 'fudging' a bit on the truth.
(HP has their Power Supply's made by another company.
Bestec, HiPro, and Delta, are three of them )
Actual wattage is more like 60 to 70 percent, of what is stated.
250 divided by 10 = 25.
25 times 6 = 150 (60 percent)
25 times 7 = 175 (70 percent)
Your Power Supply's actual maximum rated wattage, may be as low as 150 Watts!
Going with the Power Supply produces a maximum of 250 Watts;
If you are playing an intense game, or have several programs running at once, you MAY reach using 250 Watts.
Just surfing the internet? About 100 Watts.
Desktop PC plus Monitor:
1) Surfing Internet: 149 Watts, or let's just say - 150 Watts
2) Computer is maxed out running hard?
249 Watts, or let's just say 300 Watts.
Voltage times Amperage = Wattage
Wattage divided by Voltage = Amperage
Number 1 above? About the power it takes to use a 100 Watt light bulb, and a 50 Watt light bulb. (Incandescent)
Number 2? About the power it takes to run three 100 Watt light bulbs.