Another garage door question

[JayH]

2) "U" shaped photoelectric proximity sensor, not the cheapest solution, but no moving parts! Simply mount it on the frame so the bar interrupts the beam. You may need to cover the lock hole.
Example: http://www.fargocontrols.com/pdf/sensors/Fargo_Value_PU.pdf (NPN model for Elk, you can even power off Elk +12V)
Or hit up your local electronics surplus store.

Jay

The photoelectric prox sensor looks interesting. I wonder what the light immunity stats mean in the real world. Too much light from another source would trigger a false "unlocked" condition. That probably doesn't matter since the only way that would happen when the door is really locked is if I left the lights on in my shop. I would want to know about that anyway. Am I correct in thinking that too much ambient light cannot cause a false "locked" condition, i.e., the ambient light can't somehow result in the sensor not seeing its own beam?

Certainly seems like a good off-the-shelf solution, and is as cheap as wireless (cheaper since I don't have a wireless receiver in my shop and it may be too far away to ge picked up by the one in my home.

Ira

I haven't tried this, but some observations on this choice (opinion, take them as you will):
- It is using infrared, not visible, so I would _presume_ they have an appropriate detector and filter;
- Fargo Controls is a known Industrial Automation company, not a Harbor Freight, so I would expect quality even from their "Value Line";
- There is a sensitivity setting
- You can always mount it so the detector points towards the wall and cover the bar in black non-reflective tape to cut down accidental detection.

I did some looking around and this was the only one I found that had an opening > 1/4" and was "budget". If you try it, I'd love to hear how it works.

As a last thought - I don't know what a "failure" on this device would look like - you may want to put a sanity rule in "If door is open and Lock is NOT OPEN then send panic message"

Jay

 

[Ira]

I haven't tried this, but some observations on this choice (opinion, take them as you will):
- It is using infrared, not visible, so I would _presume_ they have an appropriate detector and filter;
- Fargo Controls is a known Industrial Automation company, not a Harbor Freight, so I would expect quality even from their "Value Line";
- There is a sensitivity setting
- You can always mount it so the detector points towards the wall and cover the bar in black non-reflective tape to cut down accidental detection.

I did some looking around and this was the only one I found that had an opening > 1/4" and was "budget". If you try it, I'd love to hear how it works.

As a last thought - I don't know what a "failure" on this device would look like - you may want to put a sanity rule in "If door is open and Lock is NOT OPEN then send panic message"

Jay

'Nuff said. For $35, I will give one a shot. I tried finding a place on the web to buy one, but came up empty. I guess you have to place a phone order directly with Fargo. I will give them a call tomorrow.

I will also try the mag sensor to see how good it works (since I already ordered the magnets).

Ira

 

[Steve]

That photoelectric sensor was something I was thinking but I could not find one like that so I didn't mention it since I figured you would have to rig one up yourself which you said you did not want to do. That's a great find... That sensor is 3/4" wide, hopefully the 1/2" throw is enough to completely block the sensor portion (or I guess you could always extend the bar a bit with sheet metal if needed).

 

[dBeau]

I took a rare earth magnet with a hole in the middle and used a small sheet metal screw to attach it to the very end of the locking rod. At "just the right spot", I mounted a standard window sensor (reed switch) to a metal strap and attached the strap to the 2x4 stud that's next to the door. When the rod is in the locked position, it bumps into the window sensor. But, because the sensor is attached to the strap, there is some spring action available and it just moves out of the way. To help protect the magnet, I wrapped it with electricians tape. It looks and works great. I also have another sensor at the top of the door to detect when the door is closed. My Elk now know if the door is opened, closed or closed and locked. The only tricky thing about mounting the locked sensor is the path of the wheels in the track. Some of the hardware sticks out and gets close to the sensor as the door goes up and down.

Of course what I'd really like is an electric dead bolt for the door. I've looked but cant find anything.

 

[ano]

Or you could just install a garage opener. Door closed = locked.

 

[Ira]

Or you could just install a garage opener. Door closed = locked.

True...but there are three garage doors in my shop, and the one that I open depends on what I'm doing at the time (using tractor, using mower, using trailer, working on something in the shop, etc.) so that would be substantially more money.

Ira