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House Access Help



I'm rather new at home automation. I'd be interested in feedback
regarding a plan for a passive entry system to my home.  The plan and
components I have envisioned exist but I have not seen them configured
in the way I've planned.

Pictures from the top, inside, and outside of my front door can be
found at the following urls (I apologize in advance for the smallness
of the jpg's that msn groups pulled from my computer -- hopefully my
description below will provide the detail that may be so small as to be
illegible on the jpgs):

Top View
http://groups.msn.com/HouseAccess/shoebox.msnw?action=ShowPhoto&PhotoID=3

Outside View
http://groups.msn.com/HouseAccess/shoebox.msnw?action=ShowPhoto&PhotoID=2

Inside View
http://groups.msn.com/HouseAccess/shoebox.msnw?action=ShowPhoto&PhotoID=1

Principle elements of the plan:
(1) Long range proximity reader - It seems as if the normal distance
for a proximity reader is something on the order of 6" or less. My
intention is to be able to approach my front door and have it open as I
approach without having to remove my key card from my wallet.  This
would suggest a range quite a bit longer than 6".  Long range proximity
readers are out there (HID Maxiprox) but it appears they are targeted
to parking garages and such.

Would anyone like to comment on applying a long range proximity reader
to home automation application?

Since the long range proximity readers I've come across are on the
order of 12" x 12" or larger my thought is to mount it indoors (in the
drywall??) where it is not an eyesore.  Should I reasonably expect this
sort of installation to work?  Are there challenges with this sort of
installation that I need to be aware of?

With a long range proximity reader I need to be concerned with the
distance that the reader penetrates indoors (I have provided for this
in my diagram by specifying that the read area extends only outside the
front door).  I don't want to be activating my front door once I'm
inside.  Are proximity readers typically directional?  Can they be made
directional by the use of properly placed shielding? (metal??)

(2) Keypad mounted outside - I've seen some keypads (some elegant, some
ugly) on the web (feel free to make suggestions if you would).  They
keypad would provide access in lieu of a keycard (for house cleaners,
guests, etc.) allowing me to add/remove access codes and limit access
to specific times.

(3) Control unit mounted inside - Don't know if this is the proper term
but I understand that separating this from the keypad is a more secure
solution.

(4) Electric strike - Would be activated by either proximity reader or
keypad via control unit. I like the fact that the electric strike is
mounted in the door frame and is therefore capable of being powered
without having to wire the door itself.

My expectation is that the strike, when activated, would allow the door
to swing open for some preset time.  I'm wondering about how much time
I should alot.  I suspect it's easier with a short range proximity
reader as one expects that entering the door is immediate upon
activation.  I don't want the door to prematurely "lock" so it should
be longer than 1 second delay.  On the other hand, I don't want the
door to swing open for 10s of seconds after entry so the delay should
be shorter than 30 seconds.  Is this going to be a pain in the butt?

(5) RF electric deadbolt - I would love to have a deadbolt which
functions in the same way as the electric strike.  Since a deadbolt
isn't a latch and since a deadbolt isn't spring activated it appears an
electric strike won't work with a deadbolt.  That leaves an RF deadbolt
with a key fob as an additional component to the plan.  The idea of
replacing batteries for the thing seems rather inelegant to me.  My
father-in-law suggested a second latch acting as a deadbolt (with a
second electric strike), IF there exist latches which act (and look --
who wants two doorknobs on a door) like deadbolts.  Does this beast
exist?  Would this be as secure as a deadbolt?

(6) Fail secure - Both the deadbolt and the electric strike would be
fail secure.  I would have both keyed on the outside and a handle/knob
on the inside in case of power failure.

Please feel free to comment on any or all parts of the plan.  What am I
overlooking or failing to appreciate?  What should be I looking for
from these components if I was interested in hooking this into a
comprehensive home automation system?

Thanks for your patience in reading this rather long post.

= Joseph



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