Normally closed switch
 

I recently installed one of these latches on a garage door for a very security conscious client (same guy I might install a new opener for, other thread):

http://vistagaragedoor.com/SlideLatchLock.jpg

I put another opener button over just above it as you need to release the latch before hitting the button or it binds up in an alarming kind of way. He forgets to do so now and then and is worried that he's going to do some damage. I suggested a power cut-out operated by the latch. He likes it and I thought I'd be able to find a normally closed switch easily enough, a switch that would be pushed open by the end of the steel slide bar and spring back to closed whenever the latch is released. I'd route the 110 power through it.

Not finding such a switch readily however.

Use a magnet Epoxied to the latch to control a reed switch that trips a normally closed 12v relay powered by a door bell transformer.

Run a wire with a toggle switch right by the lock so when you set the padlock, you flip this switch, disabling power to the button.

You should cut out the whole opener, not just the button since someone could still bind it with the remote.

^ That was my thought, just cut out power to the opener motor so no way does it start up period when the latch is closed.

I had a thought something like that. I was thinking to find a medium strength stretch spring and put one end through a small hole in the end of the toggle on a normal household switch and anchor the other end somewhere, holding it normally closed w/o too much pressure. Not sure if I could position it so the end of the slide bar on the latch would push it far enough. Your idea might work - I could use the same spring setup with a thin braided cable also attached to be pushed by the slide bar, maybe I'd file a small notch into the end of it so as to push the cable w/o it slipping off.

That also sounds interesting, do you mean a 12 volt relay that controls an AC switch? That would be the sophisticated way to do it. I'm surprised there isn't an off the shelf kit for this. Plenty of people have both and opener and a latch of this sort. Letting your entire house be secured by a wireless opener is a bit weird. I frequently run into people, such as my client, who do not lock the door between the house and garage. If a remote is ever stored in a car parked on the street, breaking into the car would gain access to the house.

My client is freaked that hackers will learn how to break the code for an opener. My reading tells me this would be tough but who knows. That's why he wants the latch - for his peace of mind while sleeping. He's early 70s w/money, not too strong and lives alone.

Go to local electrical supply house and tell them you want a limit switch. They will have many types. An Allen Bradley or square D distributor will have a huge variety.

There are all different types. Many of them have both N.O. and N.C. contacts.

Good tip. I suppose I was premature posting this today, when those places are closed. There are two places in my area (that I know of right off) that carry off the wall stuff like that. It helps having the right words to throw out so I appreciate that.

No, the 12 volt relay *is* a remotely operated AC switch. Whenever 12 volts is applied to the coil, it opens or closes a set of 120 volt contacts.

I'm kinda surprised that the door opener doesn't have a set screw/adjuster for "opening torque" - you should just be able to set that down a bit and prevent the binding that you are seeing.

If this is the same as the other thread - is there another person that operates this door ? might there someday be confusion/annoyance when one guy turns the power off to the door and the other wants to get in ? (I could be reading your posts wrong...)
-John

just sell him on a new opener that code hops

^ I tried to explain code hopping to him. I'm pretty sure his current unit has it. It's about 13 years old, has the safety eyes down by the floor. This guy makes bank - he's an editor, about half of his business is via Skype, but he can be clueless about the physical world. At one point the opener was stopping in mid flight and I couldn't make it right with the set buttons and dude is insisting that we need to spray WD40 at the point it's stopping. This after it effortlessly moved past that spot moments before. Something appears to be fried in its mini computer.

A few months ago, it phantom opened and closed several times and when he went to check it out, he said he saw a car make a K turn (he lives at the end of a culdesac) and take off. His anxiety was that the individual had hacked his code and was going to come back later. Probably just someone visiting a neighbor. I tried to explain the code hopping thing to minimal effect.

No I'm sorry, I have a flurry of garage door opener business going - well, two clients at once but I rarely work on the things at all. I might ought look into subbing out as a garage door guy. There's money there. Anyway, no, it's the other client shares his garage with a tenant. This guy has a single car garage and lives by himself. His son visits regularly but doesn't use the garage.

Get yourself a reed-switch...the kind that has a "paddle" on it.

Mount it in such a way that when you throw the bar through the track (w/wo the padlock) the "paddle" is depressed and it will then make/break the circuit you have feeding power to the opener-motor.

Simple and sweet.

Get a reed-switch for the rated power/current you expect to encounter with your project. To be on the safe/durable side, get the next up-rated unit...it will last longer.

A simple note: It's always best to run "low-voltage" down low where there's a chance some little "kidlette" might be goofing around...remote the AC up high and out of sight and your home-owners' insurance agent won't get all sorts of hinky on you (or your work) should something happen. Insulated terminals/spade-lugs and wiring will go along way to making everyone happy and fat like a pig.

Enjoy! :thumbsup:

^ I didn't see that one back when and I went with a basic setup, 110 all the way. I agree your method would be better in many regards but I think this will do. He has no kiddies running around and I have open wires well protected.