I'm in need of a garage door alert so there is a small red light in
the house indicating it's open.
I bought one made by LiftMaster, but it's not quite right for my
situation. It consists of a battery
powered RF sender that you stick on the garage door and a receiver
that you stick on the wall inside.
There are two problems with it. First, the sender will report it the
door closed when it reaches about 50-60
degrees off horizontal. This would work OK for a roll-up door if
mounted on the uppermost segment, but
for a one-piece tilt-open door like mine it will report it closed when
the door is still partially open, such as
I sometimes leave it while my car is cooling down. The second problem
is the receiver is not what you would
call a decorator piece. It is a black plastic case about 3"x4" with a
floppy little 8" wire for an antenna and
a wall-wart power supply. If I put it out of prominence it won't be in
clear view and thus will not meet the basic need.

I'm thinking about building one. I could easily mount a limit switch
of some kind that opens or closes when the door
is really closed. Lead wires would connect to a small circuit project
box mounted on the garage wall, the other side of which is
the living room. I would drill through the wall and mount a tiny LED
on the inside wall. If done well, it would not
be conspicuous, except when it was on.

So, has anyone done something like this? Seems like it could be done
with a transistor (or relay), a resistor or two,
and a battery holder.

BTW, the LiftMAster 915LM is for sale!

TIA

Ed

Ed wrote:
I'm in need of a garage door alert so there is a small red light in
the house indicating it's open.
I bought one made by LiftMaster, but it's not quite right for my
situation. It consists of a battery
powered RF sender that you stick on the garage door and a receiver
that you stick on the wall inside.
There are two problems with it. First, the sender will report it
the door closed when it reaches about 50-60
degrees off horizontal. This would work OK for a roll-up door if
mounted on the uppermost segment, but
for a one-piece tilt-open door like mine it will report it closed
when the door is still partially open, such as
I sometimes leave it while my car is cooling down. The second
problem is the receiver is not what you would
call a decorator piece. It is a black plastic case about 3"x4" with
a floppy little 8" wire for an antenna and
a wall-wart power supply. If I put it out of prominence it won't be
in clear view and thus will not meet the basic need.

I'm thinking about building one. I could easily mount a limit
switch of some kind that opens or closes when the door
is really closed. Lead wires would connect to a small circuit
project box mounted on the garage wall, the other side of which is
the living room. I would drill through the wall and mount a tiny
LED on the inside wall. If done well, it would not
be conspicuous, except when it was on.

So, has anyone done something like this? Seems like it could be
done with a transistor (or relay), a resistor or two,
and a battery holder.

BTW, the LiftMAster 915LM is for sale!

TIA

Ed




It is a workable (and clever) plan.
All you need is the switch, a 9 or 12 volt DC wall wart
power supply, 1K resistor and the LED. No transistors
or relays needed. Put the switch, resistor and LED
in series with the DC supply, observing proper polarity.

Pay a lot of attention to how you mount and actuate the
switch, so that it stands up to the repeated use.

Ed

I'm in need of a garage door alert so there is a small red light in
the house indicating it's open.
I bought one made by LiftMaster, but it's not quite right for my
situation. It consists of a battery
powered RF sender that you stick on the garage door and a receiver
that you stick on the wall inside.
There are two problems with it. First, the sender will report it the
door closed when it reaches about 50-60
degrees off horizontal. This would work OK for a roll-up door if
mounted on the uppermost segment, but
for a one-piece tilt-open door like mine it will report it closed when
the door is still partially open, such as
I sometimes leave it while my car is cooling down. The second problem
is the receiver is not what you would
call a decorator piece. It is a black plastic case about 3"x4" with a
floppy little 8" wire for an antenna and
a wall-wart power supply. If I put it out of prominence it won't be in
clear view and thus will not meet the basic need.

I'm thinking about building one. I could easily mount a limit switch
of some kind that opens or closes when the door
is really closed. Lead wires would connect to a small circuit project
box mounted on the garage wall, the other side of which is
the living room. I would drill through the wall and mount a tiny LED
on the inside wall. If done well, it would not
be conspicuous, except when it was on.

So, has anyone done something like this? Seems like it could be done
with a transistor (or relay), a resistor or two,
and a battery holder.

Just mount your limit switch next to the top of the door, and use the NC

Thanks, Ed. I see your point about no need for transistor or relay,
provided I can find a limit switch
with normally closed contacts. I'll start looking.

"ehsjr" <ehsjr@bellatlantic.net> wrote in message
news:pTTPj.3520$nb4.1260@trnddc08...

Ed wrote:

I'm in need of a garage door alert so there is a small red light in
the house indicating it's open.
I bought one made by LiftMaster, but it's not quite right for my
situation. It consists of a battery
powered RF sender that you stick on the garage door and a receiver
that you stick on the wall inside.
There are two problems with it. First, the sender will report it
the door closed when it reaches about 50-60
degrees off horizontal. This would work OK for a roll-up door if
mounted on the uppermost segment, but
for a one-piece tilt-open door like mine it will report it closed
when the door is still partially open, such as
I sometimes leave it while my car is cooling down. The second
problem is the receiver is not what you would
call a decorator piece. It is a black plastic case about 3"x4" with
a floppy little 8" wire for an antenna and
a wall-wart power supply. If I put it out of prominence it won't be
in clear view and thus will not meet the basic need.

I'm thinking about building one. I could easily mount a limit
switch of some kind that opens or closes when the door
is really closed. Lead wires would connect to a small circuit
project box mounted on the garage wall, the other side of which is
the living room. I would drill through the wall and mount a tiny
LED on the inside wall. If done well, it would not
be conspicuous, except when it was on.

So, has anyone done something like this? Seems like it could be
done with a transistor (or relay), a resistor or two,
and a battery holder.

BTW, the LiftMAster 915LM is for sale!

TIA

Ed




It is a workable (and clever) plan.
All you need is the switch, a 9 or 12 volt DC wall wart
power supply, 1K resistor and the LED. No transistors
or relays needed. Put the switch, resistor and LED
in series with the DC supply, observing proper polarity.

Pay a lot of attention to how you mount and actuate the
switch, so that it stands up to the repeated use.

Ed


Thanks, Ed. I see your point about no need for transistor or relay,
provided I can find a limit switch
with normally closed contacts. I'll start looking.

Ed

On Thu, 24 Apr 2008 07:18:42 -0700, Ed wrote:

Thanks, Ed. I see your point about no need for transistor or relay,
provided I can find a limit switch
with normally closed contacts. I'll start looking.

Just look for "microswitches." MicroSwitch was the name of the
original
manufacturer, but, like "zipper", it has become a generic name.
Most of
these little switches are SPDT. A good free source is old
machinery.
Old copiers, VCRs and printers usually contain microswitches, but
newer
ones may have photosensor limit detectors instead.

Ed wrote:

You can use either normally open or normally closed
contacts by wiring the circuit accordingly.

Normally open:

/ LED
V+ ---o o--->|----+
|
[1K]
|
Gnd ---------------+

Normally Closed:

+---o->o---+
| |
| LED |
V+ -----+---->|----+
|
[1K]
|
Gnd ---------------+

The most important thing is the mechanical arrangement
to operate the switch. You want to make sure that the
switch is positively actuated in both directions, but
you don't want mechanical stress placed on it. Garage
door motion is not the most gentle - so you may need to
mechanically buffer the switch so that it is not unduly
stressed.

Ed

Thanks, Stephen. I had thought about a microswitch, but wondered about
how to gently engage it.
Perhaps a strip of stiff but flexible material, metal of plastic,
mounted to the door?

Ed

"ehsjr" <ehsjr@bellatlantic.net> wrote in message
Ed wrote:

You can use either normally open or normally closed
contacts by wiring the circuit accordingly.

Normally open:

/ LED
V+ ---o o--->|----+
|
[1K]
|
Gnd ---------------+

Normally Closed:

+---o->o---+
| |
| LED |
V+ -----+---->|----+
|
[1K]
|
Gnd ---------------+

The most important thing is the mechanical arrangement
to operate the switch. You want to make sure that the
switch is positively actuated in both directions, but
you don't want mechanical stress placed on it. Garage
door motion is not the most gentle - so you may need to
mechanically buffer the switch so that it is not unduly
stressed.

Thanks, Ed. I had thought about a microswitch, but wondered about
how to gently engage it.
Perhaps a strip of stiff but flexible material, metal or , mounted to
the door?

"ehsjr" <ehsjr@bellatlantic.net> wrote in message
news:pTTPj.3520$nb4.1260@trnddc08...
Ed wrote:
I'm in need of a garage door alert so there is a small red light in the
house indicating it's open.
I bought one made by LiftMaster, but it's not quite right for my
situation. It consists of a battery
powered RF sender that you stick on the garage door and a receiver that
you stick on the wall inside.
There are two problems with it. First, the sender will report it the
door closed when it reaches about 50-60
degrees off horizontal. This would work OK for a roll-up door if mounted
on the uppermost segment, but
for a one-piece tilt-open door like mine it will report it closed when
the door is still partially open, such as
I sometimes leave it while my car is cooling down. The second problem is
the receiver is not what you would
call a decorator piece. It is a black plastic case about 3"x4" with a
floppy little 8" wire for an antenna and
a wall-wart power supply. If I put it out of prominence it won't be in
clear view and thus will not meet the basic need.

I'm thinking about building one. I could easily mount a limit switch of
some kind that opens or closes when the door
is really closed. Lead wires would connect to a small circuit project
box mounted on the garage wall, the other side of which is
the living room. I would drill through the wall and mount a tiny LED on
the inside wall. If done well, it would not
be conspicuous, except when it was on.

So, has anyone done something like this? Seems like it could be done
with a transistor (or relay), a resistor or two,
and a battery holder.

BTW, the LiftMAster 915LM is for sale!

TIA

Ed




It is a workable (and clever) plan.
All you need is the switch, a 9 or 12 volt DC wall wart
power supply, 1K resistor and the LED. No transistors
or relays needed. Put the switch, resistor and LED
in series with the DC supply, observing proper polarity.

Pay a lot of attention to how you mount and actuate the
switch, so that it stands up to the repeated use.

Ed

Thanks, Ed. I see your point about no need for transistor or relay,
provided I can find a limit switch
with normally closed contacts. I'll start looking.

Ed
Wot's wrong with a reed switch like an alarm system would use?

"ehsjr" <ehsjr@bellatlantic.net> wrote in message
news:uqbQj.11555$aq4.3152@trnddc02...

Ed wrote:

You can use either normally open or normally closed
contacts by wiring the circuit accordingly.

Normally open:

/ LED
V+ ---o o--->|----+
|
[1K]
|
Gnd ---------------+

Normally Closed:

+---o->o---+
| |
| LED |
V+ -----+---->|----+
|
[1K]
|
Gnd ---------------+

The most important thing is the mechanical arrangement
to operate the switch. You want to make sure that the
switch is positively actuated in both directions, but
you don't want mechanical stress placed on it. Garage
door motion is not the most gentle - so you may need to
mechanically buffer the switch so that it is not unduly
stressed.

Ed


Thanks, Ed. I had thought about a microswitch, but wondered about
how to gently engage it.
Perhaps a strip of stiff but flexible material, metal or , mounted to
the door?

Ed

Wot's wrong with a reed switch like an alarm system would use?

These are available in N/O, N/C and change over.

The circuit would be easy and the mounting simple.

They are available at places like Bunnings. (Home Depot to you
Americans)

John G.

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

"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.

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

to the inside of the door."

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.

Ed