I just found two power monitoring devices, one for the main power meter and one portable, that look really good. The one for the main power meter clamps the detector/transmitter to the glass cover of the meter and sends the information to the display inside the house. The portable unit has peak reading feature that others have mentioned as being useful. It also has a function to log the amount of time a device draws more then a set amount of power. You could track the time a refrigerator compressor is running for an example. Now if the main power meter transmission could be captured for the HA system all sorts of things are possible. Take a look at:
Smells more like you just spammed the newsgroup trying to sell something. Go away. Most folks will not buy from a vendor that spams newsgroups. And will go out of our way to tell others not to as well.
You'll catch less flak from self-appointed moderators if you search the group before posting with wide-eyed exuberance.
Watts Up has been around for 3-4 years. It and other power meters have been discussed here. IMO, it's a bit pricey - you're paying $100 for the RS232 (now USB) interface as compared to the Kill A Watt (previously mentioned in the reefer madness thread) which can measure the same things (with better accuracy unless the new USB model of Watts Up has improved on accuracy).
ROTFL. The Watts Up was first mention in this newsgroup in 1998! So was it Dave Houston "posting with wide-eyed exuberance" "3-4 years ago" and ~five years after it was first discussed here ? ;-) The Watts Up was initially tested marketed in 1992 and was available on-line at retail by at least 1998. Dennis, you might also check out the web site of long-time comp.home.participant who has implemented some interesting and useful DIY power monitoring See Ed Cheung's site at:
formatting link
Requires soldering skills, but might provide some ideas.
Mark, Thanks for the related links. I was more then just a little surprised at the holier then thou reaction to my post. I thought sharing both ideas and information on interesting related products was exactly what the group was all about. I remembered seeing several posts requesting information on how to monitor the main power meter, as well as posts mentioning a desire to be able to monitor peak power usage, which I didn't think the kill a watt meter would do. Here I thought I was simply passing along some useful information I ran accrossed, only to get slammed as a spammer. I also wonder how many posters search the group each time before posting a question or comment. I can personally remember seeing dozens of messages that would fail this criteria, and I for one would not slam them for it. We are supposed to be helping each other, aren't we?? Dennis
----- Original Message ----- From: "Mark_F_Hult" < snipped-for-privacy@nothydrologistnot.com
Newsgroups: comp.home.automation Sent: Sunday, February 18, 2007 6:06 PM Subject: Re: Power monitoring device
I am reminded of an old joke about the dour and dull Drill Instructor whose job it was to get new recruits off the bus and into the processing building.
"Off the bus. Turn Right. Follow blue line to blue door" "Off the bus. Turn Right. Follow blue line to blue door" "Off the bus. Turn Right. Follow blue line to blue door" and so on.
After a few dozen busloads he whines, "I keep telling them but they don't never larn".
As you may have found, there are several problems with searching the newsgroups for prior answers. You bumped into the 'territory' of one of the frequent posters who thinks 'the world begins' when he first becomes aware of something.
One of my pet peeves are the regulars who post something that they subsequently realize is [choose a polite descriptor] and then don't correct the record. They do us all a disservice by polluting the record. Sometimes too there are changes and improvements. The silliness over the compact fluorescent lamp (CFL) discussion is a good example. Folks who painted themselves into a corner years ago with ill-advised pronouncements keep trying to defend an outdated position by referring to circumstances of 30 years ago as if they were today's reality.
So ask away. You will find that even the brusque have useful things to say if you learn how to filter out self-important posturing.
(The spammer thing is different issue. Some folks have a low threshold for those that would use comp.home.automation for commercial purposes contrary to the newsgroup's charter. It's easy to react too quickly. This too will pass quickly.)
That *is* a major flaw in what otherwise is a very nice piece of HW for very little $. Hopefully, someday all devices likes this will come with some sort of output port for logging purposes.
I wanted something a little more useful so I took a heavy duty extension cord and "unzipped" it so that I can wrap a few turns of wire around one conductor and feed it into a RatShack multimeter with a PC serial port. That way, I should be able to correlate the KAW's readout with what I see on the meter's LCD. Assuming the extrapolation to be relatively linear, I should be able to monitor usage over a long period of time. My refrigerator clearly draws very different amounts of power at different times of the day. Electrical use appears to be very tightly related to the room temperature and the number of closings and openings per day.
I still won't be able to capture peak loading, but I will be able to determine, for example, how much opening and closing a refrigerator door contributes to the overall electrical usage. Of course, I'll have to log the openings and closings, but that's pretty easy to do with an old laptop running Activehome and a Hawkeye mounted inside the reefer. Whenever it's opened, it sends a signal. Hmmm. That sounds like a good way to test for open door events that last longer than X seconds as yet another way to detect imminent coil freezeups. If the dawn/dusk sensor sees too much dawn, the door must be open. With the dogs getting smarter every day, that may be a very useful sensor indeed! I'll either have to hardwire it to a 3VDC supply or load it with lithium batteries to work reliably in the cold. I'll also have to mount a TM-751 nearby since the refrigerator walls will act as a Faraday cage and limit transmission range.
Now all I have to do is to assemble all the gear, get it downstairs and hook it up. I've been casually monitoring the unit with the KAW but it's been SO abnormally cold here I am afraid the readings won't be meaningful. These HA projects always seem to stretch out a lot longer than I think they will.
Good advice, David. After a while, you even learn to ignore the posts that may have some interest or value if they turn out to be vehicles for someone's bitch fight. That's pretty sad, but it seems the only way to encourage people to behave as if they are in a friend's living room. Of course, some people will *never* get it. I wince every time I think of the newbies to HA that post here, get caught up in some bad blood that's been going on for years and are never heard from again. It's almost the rule now, instead of the exception. :-( I've had more than a couple of threads I've started get "hijacked" by one set of long standing grudge matches or another.
It's worse than that, I fear. Some people just like to fight and no amount of cajoling, bribing, group embarrassment or any other "technique" is going to break them of the habit. The exchanges will always be of the sort:
Q. Why is the sky blue?
A. Because Joe S. Ragman is a moron.
Q. How do I turn on a light remotely?
A. You wouldn't have to if Joe S. Ragman hadn't thoughtlessly turned it off. What a maroon! if Joe S. Ragman says POTAYTO, you can be sure it's really POTAHTO!!!!"
Reminds me of the guy who fixed the annual cockroach race by preheating the plate the bug had to race across. It really *flew* when it sensed the heat.
I mostly ignore the big, flaming hunks of flamebait that are frequently tossed out into the group unless I absolutely need the information that might be lurking behind the ire. That makes it worth the potential singe marks. I'm also far less likely to spend time replying to someone who seems to be a sock puppet of one of the "usual suspects." Lately a lot of CHA posts have come from people who have suddenly appeared on Usenet for the very first time but seem quite net-savvy. Very suspicious. While the protagonists take great care to assure us the flaming is for the good of the group, most people know that's just not true. It's just ego-tripping with a side-order of rationalization.
Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.