Fail-safe for keyless entry - Page 4

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Re: Fail-safe for keyless entry


wrote:
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My fob needs to be reprogrammed every time the battery is changed. I
would imagine yours is similar.

Disconnecting the battery would have the same effect. It would get
very annoying to have to reprogram the fob every time I wanted to get
into the car.

Try wearing pants that aren't so tight when you keep the keys in your
pocket.

Re: Fail-safe for keyless entry


wrote:
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the
it

<<My fob needs to be reprogrammed every time the battery is changed. I
would imagine yours is similar.>>

I inadvertently did the experiment that Ian first suggested because when the
fob is popped open, the battery goes with one half, the circuit board with
the other.  After being disconnected for several hours, it still locked the
car (I looked out the window to see the lights flash).  This is a TRW remote
for a 2002 Chrysler Grand Caravan.

<<Disconnecting the battery would have the same effect. It would get
very annoying to have to reprogram the fob every time I wanted to get
into the car.>>

Yes, that would be a deal-breaker.  That's why I suggested to Ian that I
would look for a way to insert a second switch into the circuit that did not
affect the trickle current going to the IC.  That should be pretty easy
since it's an open circuit anyway.  Adding a second switch would just mean
that both had to be pressed simultaneously.

Thanks for the caveat, but as far as I can tell, my unit doesn't have a
sophisticated fob.  Perhaps that's because the keys have RF immobolizers
built into them and the security is "concentrated" at that point.

<Try wearing pants that aren't so tight when you keep the keys in your
pocket.>

It's not only pants, it's holding them in your hand with all the other
things your hands do upon exiting a vehicle or even throwing them in a
purse.  The damn buttons are just not "stiff" enough to resist erroneous
activation.  Bad design.  From a carmaker.  Who would have ever expected it?
(-:

--
Bobby G.



Re: Fail-safe for keyless entry


Robert Green wrote:
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    Some cut.

     Check with the whiz kids at alt.engineering.electrical    Someone
there might have an idea.

Re: Fail-safe for keyless entry


Robert Green wrote:
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I don't know if anyone mentioned this but I just thought there
might be a way to make a swing cover for the remote much like
what I've seen for a small pocket magnifying loupe. I think
something like that would be the perfect thing to protect the
buttons on a key fob remote.

http://en.wikipedia.org/wiki/File:Loupe-triplet-30x-0a.jpg

TDD

Re: Fail-safe for keyless entry


"Robert Green" wrote:
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Robert, this is a fairly common problem. Can you reprogram
the receiver?  If so, set it so that it will only trip upon two
successive signals within say a 2- or 3-second interval.

If reprogramming the receiver isn't an option, consider
replacing it with something that does.  These systems are
inexpensive to build from scratch and may prove to be an
entertaining project.

I can help you select parts if you like though technically
I've retired from my online business.

Regards,
Robert

Re: Fail-safe for keyless entry


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How about putting an O-ring under each button?  Increase the pressure
necessary to activate the circuit.

It's an old-school trick learned back in the days of the Reset key being on
the Apple ][ keyboard.  Putting a stiffer spring or an O-ring under the key
made it more difficult to press it accidentally (easy given it's proximity
to the backspace key).

Conversely my wife's cell phone has buttons on the outside lid (an LG
VX8350) for multimedia "features".  The keypad underneath had little stubs
to press the switches.  I snipped off a majority of the stubs and made the
buttons much harder to operate. Stupid feature that got on her nerves
anyway.

As far as cops and calls for handicapped parking, take it up with your local
representatives.  That and the local TV stations and paper.  They're always
looking for community issue material.

-Bill Kearney


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