i plan on mounting a wind sensor on the roof of my garage. the sensor is aluminum with cups and give a pulse output. it will be wired to my arduino which is connected to my network (though a surge protector) via cat6. power is supplied over the cat6 as well (12v with a drop down to 5v at the arduino)
should i be isolating the wind sensor somehow? (ie an optocoupler, or a separate arduino with wifi), look at a different mounting location? or am i worrying about something that i don't need to be?
i googled it, and given google returned pretty much nothing on the subject makes me thing i might be overthinking this a bit.
between the arduino and wind sensor im using roughly 20' thermostat wire. between the arduino and my switch is roughly 60' of cat 6. i'm not concerned regarding the lengths or signals, but more if I should be considered about lightning or other surge issues with the wind sensor being on the roof.
Zorac:
between the arduino and wind sensor im using roughly 20' thermostat wire. between the arduino and my switch is roughly 60' of cat 6. i'm not concerned regarding the lengths or signals, but more if I should be considered about lightning or other surge issues with the wind sensor being on the roof.
What is your concern? Any lightening strike in the vicinity will kill your whole system. A direct hit will do that and much more. Do lightening strikes happen often in your area?
Google "lightening protection" if you really want to protect it.
Paul_KD7HB:
What is your concern? Any lightening strike in the vicinity will kill your whole system. A direct hit will do that and much more. Do lightening strikes happen often in your area?
not really, but we do have good lightning storms a 2 or 3 time a year, never had a strike near us though. i realize i can't protect against a direct strike, but even if they are near the could do damage. just though i would do whats prudent. i wasn't sure if by having the wind sensor on the roof if i was increasing my risk or not. maybe ill just put a physical disconnect on it for those 2 days a year.
If you live near overhead electric power lines, they offer pretty good protection. I have lots of large amateur radio antennas in the air. I can detect LOTS of clouds with electric charges and there have been lots of lightening strikes in the area, but have never had a problem. Usually the strikes here hit poles with transformers or hit juniper trees well away from the power lines.
By not having shielded wire going to the wind sensor, it may be more susceptible to lightening induced voltages. If you do shield it, be sure to ground it only at the end closest to the real earth ground. Otherwise it will also become an electrical conductor and not a "shield".
thanks paul, shielded wire is probably a good idea for all my external sensors, not just the one on the top of my roof! i had only though to use shielded cable when trying to protect signals in the cable, not for induced voltages.