Garage door alert

[ehsjr]

Ed wrote:

"ehsjr" <e.h.s.j.r.removethespampunctuation@bellatlantic.net> wrote in
message news:CtyQj.3745$E77.1973@trnddc05...


Here's one idea:

| <--door
|
|| _
|| | | <--weight
|o--------- <--hinge
| o------.
| | | <--micro switch
| -----

A cheap strap hinge that can pivot to a 90 degree angle mounted
to the inside of the door. A small weight on the end of the hinge.
When the door comes down, the hinge contacts the roller on the
microswitch and the switch transfers due to the small weight.

Because the hinge can pivot, the herky-jerky door motion does
not transfer to the switch, nor can the assembly drive the
switch too hard if the door goes a little bit farther.
Also, you can install it such that the micrtoswitch transfers
when the door is within say 1 inch of fully closed. That way,
if the door stops a little bit shy of fully closed, the
switch still transfers.

There's nothing critical about dimensions - the hinge need
not be at a perfect 90 degree angle when in contact with the
switch. The weight can probably be a #10 machine screw
with two nuts. (Two nuts so that it locks - but I'd also use
locktite or nail polish or paint on the threads.)

There are undoubtedly many other ways you can do it.

Ed


I must not be thinking clearly, as I can't quite see how this would
work. The free side of the
hinge would be hanging vertically, perpendicular to the door, when
open.

Yes.

It would still be
hanging vertically, but parallel to the door, when closed

No - I think you missed the 90 degree part:
">>A cheap strap hinge that can pivot to a 90 degree angle mounted

to the inside of the door."

The hinge makes an L when the door is closed, with the
vertical leg of the L screwed to the door and the horizontal
leg parallel to the floor, because of the 90 degree limit.

But unless
the switch was also mounted on the
door I don't see how the hinge would operate the switch.

Anyway, I looked at the door more carefully and see I may not have as
much of a problem
as I thought. The top edge of the door is stopped firmly by the beam
forming the top of the doorway.
Since it is pressed tightly against the beam when closed, if I mount
the switch carefully it can't
get damage. I think I'll give that a try. After all, the switch cost
me only about $5.00.

Great!

Ed

Ed

 

[ehsjr]

Ed wrote:

Just want to show off the finished project!

http://www.efsowell.us/ed/projects/garagedooralert/GarageDoorAlert.pdf

Thanks for all the help!

Ed

Nice! Good idea making the red LED a flashing type.
The resistor you mention in your writeup is 1000 ohm
or 1K - not 1000K as the writeup says..

The appearance in the living room is great - barely
noticeable. Nice to see the photos of the completed
project.

Ed