Introduction: How to Install a "garage Door Open" Indicator

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Ever left your garage door open overnight? In addition to being a terrible energy waster, all the tools, bikes, and other stuff are available to thieves - who might even enter your home via the door from your garage to your living quarters.

Install a simple indicator which will alert you if you've left the garage door open. Total cost is less than $30-$40, and you can determine exactly where the indicator will be located.

What you'll need:

-A 24 volt doorbell transformer
-1 push button "normally open/momentarily closed" switch
-1 red LED - 2.8 volts
-1 4.7k-Ohm resistor (specific part numbers for the electrical components are provided in Step 2)
-2 strand bell wire
-Electrical tape and/or heat shrink tubing

-Wire strippers
-Soldering iron + solder
-Electric drill
-Misc. hand tools - wrenches, etc. - depending upon the specifics of your installation

Let's get started...

Step 1: Identify a Switch Location

Your first step will be to determine where you can put a switch to close the indicator LED circuit.

When I looked at my garage door, I noticed that a piece of galvanized trim on the top of the door stopped right next to the angle iron used to hang the door tracks when the door was in the fully opened position.

I bought a simple corner or "L" bracket and mounted it from the bolt that connected the wheel track of the door to the vertical angle iron bracket. A simple Radio Shack "normally open/momentary close" push button then mounted on the other side of the corner bracket, with the switch of course facing the top of the door.

By bending the bracket slightly, I was able to ensure that the switch was fully depressed every time the door was fully opened.

This arrangement might work for you, or you might have to improvise a bit. You of course want to mount the switch in a manner that it's in the "closed" position when the door is open.

NOTE: in the image below, I stopped the door's movement before it reached the fully open position so you could see the orientation of the switch in relation to the top of the door. When the door is fully open, the red push button is fully depressed, and the circuit is closed. (See 2nd picture below.)

Step 2: Wiring Diagram

Before we go any further, a simple wiring diagram.

The system uses a 24 volt doorbell transformer as the power source; a 4.7k-Ohm resistor knocks the voltage down to that required by the LED (~2.8 volts.)

All of the electrical components are available at Radio Shack and will cost approximately $6.

In addition, you'll need some 2 strand bell wire; how much depends upon where you plan to put the LED. More on this later.

All of the Rat Shack part numbers are indicated in the diagram.

Let's take a look at how I mounted the doorbell transformer in the next step...

Step 3: Wiring the Transformer

I used a variable voltage (8-16-24 volt) doorbell transformer made by Heath/Zenith. It cost about $15 at my local home center. You need a transformer that produces 24 volts.

I direct wired the transformer to a grounded, 3 prong plug and mounted it directly above a power strip near my workbench. The 4.7k-Ohm resistor was soldered in place and then secured with a piece of heat shrink tubing I had on hand; it's directly beneath the transformer in this picture.

If you wish, you could cover the wiring with plastic channel for a neater appearance; I simply chose to use insulated staples.

One other thing I did later on was to plug the power strip into a lamp timer, and set the timer so the strip is on only between 8pm and midnight. There's no reason to power the transformer 24/7, as the only critical time is at night when we're going to bed and (presumably) have forgotten to close the garage door. Which leads us to the final step...

Step 4: Install the Red LED Indicator

After thinking about this for a bit, I figured that the absolute best location for the "door open" indicator was in the master bedroom.

It could have gone in the kitchen, or mud room (whose door connects to the garage) but my logic was "if I could remember to look at an indicator in one of those rooms, I could just as easily remember to open the mud room door and check the garage door."

To be absolutely foolproof, I thought it had to be in the master bedroom. Looking around the room, I thought of getting at the ceiling light fixture via the attic, and perhaps placing the LED inside the light's frosted globe.

In the end, I decided to drill a small hole in the decorative trim on the light, oriented so it faces the head of our bed. That way, if the LED was illuminated, you couldn't help but notice it when you went to bed.

I was able to route the wire from the garage all the way through the attic to the location of the master's ceiling light. (NOTE: this was the most time consuming step in this project.) Working from the bedroom, I drilled a small hole next to the light's electrical box, within the diameter of the light itself. I then fished the wire through from the attic, and made the connections to the LED. (As with the resistor, the wires were soldered to the LED's leads, and everything secured with heat shrink tubing. You could use electrical tape for this; just make certain everything is sealed really well.)

And that's it. As mentioned earlier, I put the system on a lamp timer so it's operational only in the evening.

It works perfectly, and we're now assured that if we forget to close the garage door before retiring, the LED will bring us back to our senses.

Total cost of this project was around $40, and that included 120 feet of bell wire. YMMV; bell wire costs about $ .20 per foot.

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