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IceTeks Articles -> Testing Wattage consumption of your equipment
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| Red Squirrel - Aug-23-2004 server time |
lol. I knew this article would get lot of safety concerns.  If you use common sense, dangeraus situations can be made safe.  |
| safety alert - Aug-23-2004 server time |
| You're a fuckwit for showing current measurements using bare crocodile clips on mains-powered AC voltages. |
| Red Squirrel - Aug-23-2004 server time |
I've been zapped many ways and I can easly say from experience the most fatal is the heart thing like mentioned. By nature some people are forced to hold on tight to whatever they are being zapped by. Thankfully for me I'm the oposite. I got zapped with who knows how many amps from arm to arm, and I felt it for like an hour. It was only 120 volts. The zap might of lasted about a milisecond or 2 but enough to make me tempoarly black out and "wake up" 5 feet behind me. I was laughing though but it would of been fatal. Stupid guy put the ground wire in the live and I was holding the "grounded" device in one arm and went to unplug it with the other. Zap!  |
| masher - Aug-23-2004 server time |
| > "Did you knew that dangerous currents are measured in tens of milliamps?" Actually, there's two ways electricity can kill you. The first is the method used by the electric chair...enough power to to simply fry you, in which case the current level doesn't matter. Its the total wattage that counts. The second is a current passing through the region of the heart, in which case the current level is crucial...from 50 to 200 mA, depending on a few factors. This causes the heart to fibrillate, and leads to death. Lower or even higher current levels are safe, interestingly enough, though a high enough level will cause the heart to asystole...to stop beating totally. Its more complex than this, as AC induces fibrillation far more easily than DC...but DC induces asystole much easier than AC. And even the safe AC current level varies based on frequency, voltage, and waveform. Finally, the resistance of the human body tends to decrease somewhat the longer current passes through it...so what may start out as a safe current may quickly become a deadly one. |
| Privatteer - Aug-23-2004 server time |
| With RMS meter that could be as high as 2.1amps 5 harddrives, 1 cdrom, 1 dvd drive gf4 4200ti, xp1700 cpu. Cheap skyhawk 400w powersupply thats probably not very efficient. I'ld give you figures for my p42.8 but my meter took a dive from the top of a ladder and is still getting repaired. Instead of a load having a constant impedance drawing current in proportion to the sinusoidal voltage, electronic psu change their impedance by switching on and off near the peak of the voltage waveform. The circuit of the power supply only draws current from the AC line during the peaks of the voltage waveform, thereby charging a capacitor to the Peak of the line voltage. The DC equipment requirements are fed from this capacitor and, as a result, the current waveform becomes distorted. Since the amount of disortion changes between every powersupply a table would be pretty difficult to do. |
| Red Squirrel - Aug-22-2004 server time |
| Yeah I discovered that after, so I had added it at the end that it may not be very accurate. I'm not sure if mine is RMS or not, but I doubt it since I only paid about $100 for it. Later on I'll try to figure out a better way (low cost) to measure true RMS with any meter. (maybe plug the results in some formula or something but I doubt it's that easy) 1.24 is pretty high for 240 bolts, do you have lot of high end stuff in it? Mine ran at about 1.2 (inacurate though) at 120 volts. |
| privatteer - Aug-22-2004 server time |
| When an average response ammeter is used to measure nonlinear load current, ie pc power supply, the results can be inaccurate readings of as much as 25% to 80% the actual true-RMS current. This is an substantial difference. I would expect your meter to be ARA as True RMS meters are a lot more expensive. My Pc for example measures at .8 Amp with a ARA, but with the correct meter runs at 1.45amps (@240volts) |
| Red Squirrel - Aug-22-2004 server time | ||
It's possible to do something dangeraus and still know what you're doing. Look at those crazy stunt people like jackass. It's unsafe, but they know what they are doing so they (usually) don't get hurt. As for the accurcy, I sort of realized that afterwards, when I did more research, but this method will still give you at least an idea of wattage. If you can afford the fancy stuff that does it right good for you, but especially here in Canada it's not obvious to get the fancy stuff, sometimes it's too expensive, sometimes you can't even get it period. |
| Guest - Aug-22-2004 server time |
 Just use this !! It tells you how much watts your system is using. |
| Guest - Aug-22-2004 server time |
| Just buy yourself a Thermaltake TWV 480 Watt Viewer and is a lot simpler and safer !! |
| The Prophet - Aug-20-2004 server time |
| Excellent presentation unfortunately your theory is flawed. Watts = Amps X Volts in Direct Current (DC) circuits only. In Alternating Current (AC)circuits Power(watts) = Volts X Amps X Powerfactor or usually written as V I pf. The Power factor is a number between 0 and 1 depending on the characteristics of the circuit under test. The power factor is a measurement of how much the current is out of phase with the voltage ie) do they reach their peak values simultaneously or at some time apart in each cycle. In Inductive circuits ie) coils, motors, transformer windings then the pf is lagging ie) the current peaks behind the voltage. In capcitive circuits ie) capacitors, long transmission lines, synchronous motors etc then the pf is leading ie) the current peaks before the voltage. What you are measuring in your test is the Input Volt Amperes (VA). This is likely to be higher than the actual wattage so is an indication of loading course but what it is not is the powere supply Wattage. The Prophet IEE |
| James - Aug-20-2004 server time |
Can you say 'Clamp on ammeter'? |
| Fin - Aug-20-2004 server time |
| First you say "I knew what I was doing" and then in next sentence "Please realize that this activity, especially with amp readings over 1 can be fatal!" There is a little conflict between what you say. Did you knew that dangerous currents are measured in tens of milliamps? Resistance of person is limitting current, so current in machine doesn't mean anything. Current depends of voltage and resistance so big voltage is the dangerous thing in these measurements. |
| Hung - Aug-20-2004 server time |
| The testing setup for current measurement using crocodile clips seem unsafe. It would be better to wire everything onto a board using proper plugs/sockets. Regards. Hung KH Singapore |
| Red Squirrel - Jul-14-2004 server time |
| Measuring your equipment’s wattage is a good way of knowing if you are overloading your UPS, or if you have too many things plugged in to the same circuit. This article will show you how you can test wattage of your equipment using a multi meter and a few wires... http://www.iceteks.com/articles/db.php/act...e/pcwattage/p/1 |
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