How are you getting the relay power to the relay? Along the same cable as the 1-wire network? It kind of sounds like it.
It would be useful to know how long the wire run is, what gauge wire is used, and what the relay coil specs are (resistance, voltage, current, etc.). Generally speaking, with one wire devices that use any amount of power, there are two ways that power is delivered: 1) A higher voltage is provided on the same cable as the 1-wire. Often this is 12V or more. Then a point-of-load regulator is provided where this power is used. In your case, this would be at the relay. 2) Provide the (regulated) power required directly at the point of load - at your relay. Do not use the 1-wire cable as an auxiliary power bus. I also kind of wonder if you're really turning that 2N2222A on hard enough. I would have thought a 4.7k more appropriate than 10k for the pull-up (and not sure I understand the need for the 1k base resistor). Again, what are the relay coil specs? If we assume something like 40ma and 125 ohms, then we know we can safely drive the transistor fully into saturation with no current limiting collector resistor. If the beta of the transistor is 100, then we'll need 400ua of base drive. The 11k that you have when the circuit self biases as the output of the 2406 floats barely provides that. Also, have you considered a BSS110 as a high side FET switch (or maybe a 2N7000 as a low side switch)? Then you are pretty much just dealing with the gate voltage and no biasing issues. Caveat: It's been a while since those ET classes in college, so I could well be talking nonsense. But hopefully this is of some help. On Mar 20, 2011, at 6:26 PM, Mick Sulley wrote: > Hi, > > I have expanded my network to about 20 DS18?20's and all was fine. I am now > trying to add some I/O using Embedded Data Systems D2P modules which use > DS2406. I need to switch mains voltage so built circuits to switch relays > with the D2P units. > > The network is basically Cat 5 cable with some spurs off in 4 core phone > cable. I had some concerns over power requirements a while back and decided > to use 2 separate 5v power supplies, one for the sensor circuit and one for > the relay circuits. > > I added one of the D2P units and it seemed OK, I then added a couple more and > the network crashes. Using owfs and looking at the directory structure I see > various things, maybe no devices at all then refresh and see a couple of the > temperature devices, refresh again and see nothing, etc. > > The D2P unit that caused the crash was at the far end of the network, I > unplugged it and plugged it in half way down and it worked. I put it back at > the end and unplugged the relay +5v supply and it works (but obviously the > relays don't work). Not sure if this diagram will get through, the circuit I > have used is - > > > <unknown-BFUOSV.png> > > I am really stuck here, I don't know what to do next. Can anyone help please? > Thanks > Mick > ------------------------------------------------------------------------------ > Colocation vs. Managed Hosting > A question and answer guide to determining the best fit > for your organization - today and in the future. > http://p.sf.net/sfu/internap-sfd2d_______________________________________________ > Owfs-developers mailing list > Owfs-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/owfs-developers ------------------------------------------------------------------------------ Enable your software for Intel(R) Active Management Technology to meet the growing manageability and security demands of your customers. Businesses are taking advantage of Intel(R) vPro (TM) technology - will your software be a part of the solution? Download the Intel(R) Manageability Checker today! http://p.sf.net/sfu/intel-dev2devmar _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
