picobay.com — These days, EVERYONE is interested in lowering their household electrical consumption. One way to help do that is by tracking and understanding power usage real-time (not a month later when you get the electric bill). The following will describe the details involved in making a safe, real-time web based household power usage chart for cheap.
Jan 20, 2009 View in Crawl 4
Closed AccountJan 20, 2009
the software would monitor your actual electricity usage in each room.
dearinternetsJan 20, 2009
"Or worse, their electronics"You got that backwards right?
spaceyraygunJan 20, 2009
because there isn't a little tag on every appliance that tells you how long you've used each appliance. or how long one has been in standby or some other way appliances drain electricity without you knowing about it.
ogarzaJan 20, 2009
Besides, this monitor assumes the power factor is 75%.. wth?Everyone knows that the appliances that are the big consumers do not fall in the average power factor.You will either have a PF close to 1.00 for resistive loads like heaters, toasters, ovens, stoves. But for an inductive load like motors and pumps it will be closer to 0.60.This is a nice way to know when something is using power, but you can't tell how much, since the spikes in the graph are the ones with the extreme PF conditions and will either be much or too little, the averaged loads are the constant ones in the background which you will not notice at all.If someone want's to take on this project himself, I suggest sampling the current and voltage and their displacement. A simple enough mod to the article's project.However the method in the article is more of a novelty and conversation piece than an actual power meter.
rustmanJan 21, 2009
This guy has been monitoring everything in his house for a while. You can see it all on here >> <a class="user" href="http://bwired.nl/">http://bwired.nl/</a>
martoqJan 21, 2009
If you will notice he is connecting the clamps to the incoming street circuit. Shutting off the main breaker won't do dick unless your power company has an outside shutoff...which most don't.
duffahtollaJan 21, 2009
I had to look it up myself, but it kinda looks like you do need to consider the phase..<a class="user" href="http://en.wikipedia.org/wiki/Electricity_meter">http://en.wikipedia.org/wiki/Electricity_meter</a>Electrical Meters don't need to consider power factor because they monitor the voltage and current simultaneously. New ones measure instantaneous voltage and current readings to measure the power. Older ones combine the force from two magnets, one generating a force proportional to voltage and the other current. But like tightscrummy said, looking at the Amps x Volts label of a device wont give you that. And the DIY device looks like it's using only an inductive sensor to measure the current. He's just initially assuming the voltage is in phase. Since it generally won't be, he's applying an approximate power factor to adjust the output reading.
haikufuJan 22, 2009
It's a USB port, says right on their site.
mati2Mar 13, 2009
ok left with no words ..::buried::..