constant to momentary

Hello All, 

I have read the posts concerning the Constant to Momentary Circuit and believe that it will help with the final circuit that I need to build.

Here is what I need to do.  Connect two wires (short them) for a small duration as if someone pressed a button for a moment.

Essentially I have a home automation system and would like to use an existing Applainace Control Module to simulate someone pressing my interior button of the garage door opener.

The Applicance Module will respond to commands and provide a constant 120 Volt AC output and then respond to another command to remove the 120 V AC output.

I have gone this far.

Hooked up a standard (cell phone charger transformer) ( 120 V AC to 9 Volts DC ) to the Applicance module. So when the appliance module is on and supplying 120 V AC I get 9 Volts DC over the two wires that come off of the transformer.  Ran the 2 wires from the transformer to a standard SPST Relay on pins 85 and 86. This DOES latch the relay and the coil is energised as long as there is power supplied. This creates a connection ( continuity) between pins 30 and 87.  I could connect the 2 wires from the garage door button to these pins , but that would just simulate the button being pressed indefinately.  I need the connection to drop away after a second or so.

Then it would be great if then when the applicance module turns off and removes the 120v AC->9 volt DC source voltage then the contacts are shorted or closed again briefly.

This would allow me to press once on the home automation controller and supply 120 V AC- >9 V DC and short the connection thus opening the garage door and then press again and remove the 120 V AC -> 9 V DC souce Voltage and then short the connection again thus closing the garage door. And over and over... :)

I really cant visulaize how to do the entire circuit so I thought I would post up and let HoTWater Wizard and others a chance to conquer this one!

Thanks mucho!

Good suggestions.  Since the applicance module works off of the house's 110 V supply and the signal to turn off or on is sent through the line then yes it may be prone to spikes and such that could cause funky operation. 

I can build the simple circuit and try it out to see how it actually performs. If it is glitchy then I can substitute another solution.

Since I have a push button panel on the kitchen wall that would interface with the existing light control modules already installed and now the new applicance module for the GDO then I would not be so inclined to carry a remote in my pocket, but more likley to want to tap the button to open the garage from the kitchen before I venture out to the garage. So portability of the remote is a seconday concern as I could always carry my small GDO remote in my pocket. Ive got too much in my pockets already and tend to forget to load that remote in the pocket as well so a hard wired (sort -of) solution would be helpful.

Whats an RKE though?  Logic gates? What configuration? And's and NOR's and such? How would they layout?

I sketched the bare details in the picture linked at the period at the end of the sentence in my first post-  you'd use an exclusive-OR gate and an inverter along with a resistor and cap to do the timing of your pulse.  I'm not at a computer with the program I usually use to draw things, so it's just a crude picture, which is why I didn't figure I'd put it out in a more obvious link.  I was going to sketch it out better later on, but if you want to get a look at it now just click on the period. Sorta like an easter egg

The output would be used to drive a transistor stage to drive your relay, not shown in the picture.

RKE is just a remote keyless entry module intended for controlling car door locks.