[TCML] Fried It !/filtration
TeslaMiles at att.net
Wed Nov 10 04:15:22 MST 2010
Personally, I believe any leakage of RF or EMI around a filter would not be significant to distroy any device that is properly grounded. I do believe any wires connecting to a device can "pick-up" random RF just like an antenna and depending on the source location and power level CAN be distructive to electronics connected to them.
In the case of my irrigation system controller I firmly believe the zone valve control wires acted like an antenna and carried RF directly into the controller. There two cables, five conductors each feeding into the control unit. I do not believe the power source for the controller had anything to do with the failure.
I'm thinking if I place a ferrite core on each cable as close the terminal connections that it may protect the device. Thoughts?
Or I just might take Gary's advice and build a quick disconnect with a ten pins connector.
Sent from my iPhone
On Nov 9, 2010, at 10:28 PM, dave pierson <dave_p at comcast.net> wrote:
Random thoughts, from some history in the field:
as noted, limitation exists in EMI radiating around filters,
including with enough energy to damage things.
ANY wire can pick up and reradiate EMI.
While filters are somewhat directional, they are not
hugely so. If cheap: use back to back.
'line filters' are used to meet FCC/etc specs down
to fairly low freqs, disrecall limit but 100 KHz is tested to,
and lower. Likely data on line, if looked for.
Disconnecting victim leads, where practical (wiring to garage
door, irrigation controllers is effective, and MOST effective
if the disconnect is as near the 'victim' as possible.
While a coil operates at 100KHz, say, fair amounts of power
may exist at higher/harmonic freqs...
While cars do have electronics, the manufacturers (NOW...)
have fair experience (and embarassment) in getting them
emi/rfi resistant. There Are Tales from the old days...
New dwp: dave_p at comcast.net
Tesla mailing list
Tesla at pupman.com
More information about the Tesla