X10 and Fluorescents
- Thread starter compuguru
- Start date
Metal boxes isolate the transmission of an RF signal. A Z-wave device installed in a metal box will emit RF signlal via the front of the device only becuase the other 6 sides are blocked. In theory it can affect the impedance of the transmitng/receiving antenna. This is one reason for which a discarded the option of z-wave.KenM said:
KenM
Active Member
This isn't purely scientific but hopefully it will help.
The white thing on the end of the wire is my Z-Wave USB interface connected to a USB cable. The Z-Wave antenna is located inside the interface.
I made a foil box about the size of a Jbox, connected it to electrical ground, and sealed in the Z-Wave interface.
I then fired up my control software and was able to talk to all of the devices in my Z-Wave network with no problems at all.
The point here is that at 900 Mhz the jbox has dimensions close enough to the wavelength of the RF that it could actually serve as a very good radiator. In my case it must have because there was no way for the RF to leak out of that foil box.
Most people picture RF as a beam of light from a flashlight. RF at high frequencies can do some mighty strange things.
I am not saying metal will not affect the Z-Wave signals. I am trying to say that metal jboxes will not necessarily stop the signals.
Ken
The white thing on the end of the wire is my Z-Wave USB interface connected to a USB cable. The Z-Wave antenna is located inside the interface.
I made a foil box about the size of a Jbox, connected it to electrical ground, and sealed in the Z-Wave interface.
I then fired up my control software and was able to talk to all of the devices in my Z-Wave network with no problems at all.
The point here is that at 900 Mhz the jbox has dimensions close enough to the wavelength of the RF that it could actually serve as a very good radiator. In my case it must have because there was no way for the RF to leak out of that foil box.
Most people picture RF as a beam of light from a flashlight. RF at high frequencies can do some mighty strange things.
I am not saying metal will not affect the Z-Wave signals. I am trying to say that metal jboxes will not necessarily stop the signals.
Ken
BraveSirRobbin
Moderator
Good test. Can you also try it with the transmitter/receiver far away (say simulate the same distance it may be from a switch in your house).
Signal strength will fall off as a function of the square of that distance.
Signal strength will fall off as a function of the square of that distance.
KenM
Active Member
Hi BSR,
For this test I was actually communicating with my installed Z-Wave switches, from the USB interface in the metal foil box at my computer. The nearest actual device is mounted in a wall switch about six feet away so that would have been the one I was communicating with. The way Z-Wave works is that you only need to talk to the nearest device and then the signal gets relayed to your end device. That is why the remotes work so well. I cannot increase the distance unless I start removing devices from my network. I may try that at some later date, I just do not have time for that now. That is a little like un-linking Insteon devices, it gets complicated in that if you leave any broken links the network may slow down.
As I said, this is not real scientific, I have no idea what I did to the signal strength. I was just trying to clear up a misconception about metal boxes and Z-Wave. Metal boxes do not necessarily stop Z-Wave from working in any one direction.
Ken
For this test I was actually communicating with my installed Z-Wave switches, from the USB interface in the metal foil box at my computer. The nearest actual device is mounted in a wall switch about six feet away so that would have been the one I was communicating with. The way Z-Wave works is that you only need to talk to the nearest device and then the signal gets relayed to your end device. That is why the remotes work so well. I cannot increase the distance unless I start removing devices from my network. I may try that at some later date, I just do not have time for that now. That is a little like un-linking Insteon devices, it gets complicated in that if you leave any broken links the network may slow down.
As I said, this is not real scientific, I have no idea what I did to the signal strength. I was just trying to clear up a misconception about metal boxes and Z-Wave. Metal boxes do not necessarily stop Z-Wave from working in any one direction.
Ken
Insteon didn't work either. It worked in nearby outlets, but not the ones that are further away, but I am not sure if that is a noise or phase issue. I ordered a signal tester from AO (The one you "buy" then can return) and will use that to see just how much noise there is.
If it is only a noise problem, could I get a couple of these: http://www.smarthome.com/4835.html and wire them into the Fluorescents ballast where they connect to the switch?
Also, what is the easist way to determine if two outlets are on seperate phases?
If it is only a noise problem, could I get a couple of these: http://www.smarthome.com/4835.html and wire them into the Fluorescents ballast where they connect to the switch?
Also, what is the easist way to determine if two outlets are on seperate phases?
WayneW
Senior Member
Use an extension cord to bring one outlet closer to the other one. Use a voltmeter between the "hot" blade of one outlet and the "hot" blade of the other outlet. If you get 0 volts, then they are the same phase. If you get about 240 volts, then they are opposite phases.compuguru said:
I plugged in my tester, and got .1V on noise, with the 3 largest banks of fluorescent lights on. There are many smaller banks fluorescents that were off. I looked at hardwired systems, and they were way to expensive. It looks like a PLC system is not going to work. 
I figured I could use Z-Wave and mount a remote on the wall to work like "keypad". The only thing I couldn't figure out is how to get something to send IR commands based on Z-Wave commands. Any ideas?
I figured I could use Z-Wave and mount a remote on the wall to work like "keypad". The only thing I couldn't figure out is how to get something to send IR commands based on Z-Wave commands. Any ideas?
upstatemike
Senior Member
What is the deal with Z-Wave and keypads anyway? Are they planning to release any in the near future?compuguru said:
upstatemike
Senior Member
It is probably neither of those. More likely a "signal suck" issue. I have a lot of fluorescent lights and they do not impact my Insteon signals. How many Insteon devices do you have installed? (Since each is a repeater, the more the better.)compuguru said:
upstatemike
Senior Member
What if you put an RFLinc close to the ControLinc and another one close to the LampLinc? This way it will use RF to "bypass" the signal suck zone and it should work OK.
I used those filters for all our compact fluroescent ceiling cans, and we haven't had any problems at all. Smarthome seems to be out of stock at this time. Worthingtion may have some.
To check phases, you can measure between the hot pins on the two respective outlets (use a polarized extension cord if necessary). You will read near 0VAC if on the same phase and 230VAC if on opposite phases. BE CAREFUL!
Jeff
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