Ok, crazy idea, but I got this HUGE garage door opener, and since I have a 92 convertible, the sun visors are small and this thing would constantly make it fall down. I took it apart and the board is very small, so....

I want to hide the components somewhere, and wire up a button.. The problem is that I have no idea how to go about getting 9v out of my electrical system.. Any hints would be appreciated.

Thanks

 

Wire it up to a regular nine volt battery that can be replaced easily.

 

That would be too easy!!! \

Actually I want to put it in the header above the windshield.. Even if I did wire up a 9v battery, I would have to remove the whole piece just to replace the battery, much easier to just wire to 12v.

 

Why, you can always extend the battery leads and run them down the "A" pillar post to a spot under the dash.

 

I would do a permanent installation. Go to radio Shack and get a DC to DC Adapter. Here are two models:
1. 9-Volt Vehicle DC to DC Adapter
2. Universal Vehicle DC to DC Adapter

You can gut it out and put it in a small project box also available from RS, and hide it under the dash. Then run the output wire up the pilar to where you want it.

-Ozzy

 

I would use a 9 volt lithium battery in the header. These batteries are expensive but they last for YEARS. They can be hard to find (I think Radio Shack has them). No need to run any wires!

 

An alkaline 9-volt battery would last for years in that type of application; it's not like you'd be changing it two or three times a week.

 

Look at the link below. They have a simple schematic to get 9volts just what you probably need

http://www.uoguelph.ca/~antoon/circ/car912.htm

 

Build a small power supply using a 7809 voltage regulator. Modify the garage door opener so that the button switch is closed at all times (remove switch, solder contacts together on circuit board) and use an external hidden pushbutton to send power to the opener. This saves power and generates no heat, so you don't need to heatsink the regulator.

At least, this is how I do it...

On my GP, I have the (+) side of the power tied to the "flash to pass" circuit and the (-) side tied through a hidden button and the ignition switch. So, to get into my house, you need the key in the ignition, the flash to pass high beams on, and then you have to find the button. (All this after you defeat the car alarm...) And if anyone gets that far, you'll meet me and Mr. Smith&Wesson...

 

Yes, an LM7809 is the way i would go.....