Re: Garage door opener protection

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

One also needs to be careful about the low voltage lines to the safety
sensors.  My opener has an optical "beam breaker" kind of thing to keep you
from closing the door when there is something in the way. An evening of
quarter shrinking about 2 meters away killed it, preventing closing the
door remotely (although it still opened ok.. the beam breaker only prevents
downward motion).





Tesla list wrote:
> 
> Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Gary.Lau-at-compaq-dot-com>
> 
> Unplugging just the power cord is not enough.  Most door openers also
> have low voltage wiring going to remote pushbuttons and safety sensors.
> These inputs are surely more sensitive to HV transients than the AC
> mains wiring, and need to be disconnected as well.  Don't forget, the
> opener's chassis is effectively tied to ground by virtue of the metal
> frame, and any wire extending from the box is a capacitively-coupled
> antenna to your streamers.
> 
> Install a 3 (or whatever) position connector on your control wires as
> close as possible to the opener (couple inches max) to make it easy to
> connect and disconnect it.  I also tuck the short wire antenna back into
> its hole in the chassis.  Using this precaution (and no Faraday cage),
> my coil regularly connects to the opener's steel track with no ill
> effects.  See http://people.ne.mediaone-dot-net/lau/tesla/sparks.htm
> 
> Gary Lau
> MA, USA
> 
> -----Original Message-----
> From: Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Sunday, June 10, 2001 11:19 PM
> To: tesla-at-pupman-dot-com
> Subject: Garage door opener protection
> 
> Original poster: "Steve White by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <slwhite-at-zeus.ia-dot-net>
> 
> I am in the process of buiding a pole transformer powered coil
> theoretically
> capable of 8 foot arcs. I would like to run this coil at perhaps partial
> power
> in my garage at times. Like many people, I have a garage door opener. Is
> there
> any advice on how to protect the opener from damage? The only idea that
> I have
> is to build a grounded Faraday cage around it and unplug its power cord.
> The
> Faraday cage will take care of the electric field but what about the
> magnetic
> field?