SynysterHD

Thanks Otis! Hope it works out for you also!

Canibeat

You could probably get away with just using a 7809 voltage regulator 12V goes in pin 1, pin 2 is common ground and 3 is your 9V output. Good luck!

Rednroll

There's a few easy options, using a resistor voltage divider is probably the last one I would suggest.

Here's my suggestions:

Least Technical:
1. Forgot about dropping the voltage. The garage door opener "probably" could handle 12Volts. This obviously has a risk that it also "might" not be able to handle the additional voltage and burn out your opener.

2. Buy a cigarette lighter 9 volt DC cell phone charging adapter. This has all the circuitry built into it to drop the voltage for you. Wire accordingly.

More Technical better solutions:
3. Use a voltage regulator IC as Canibeat suggested.

4. Build your own voltage regulator circuit.

This would be my recommendation and is actually quite easy.
Parts Needed, available at any Radio Shack:
- 9 Volt Zener Diode (Often they come in "9.2" Volt values also)
- 1K resistor.

This works very similar to what you where thinking when you mentioned using resistors to create a voltage divider, but instead of wiring 2 resistors in series with each other, you wire the 1K resistor in series with the 9 Volt zener diode in a similar manor but don't have to do those calculations and works better. The way a 9 Volt zener diode works, is that it maintains a 9 Volt drop across it independent of the total voltage across the circuit, where anything above 9 Volts get dropped across the 1K resistor where a 9 Volt drop is maintained across the Zener Diode when they are wired in series with each other.

You would wire it like this. Wire the 1K resistor and Zenor diode in series in the following arrangement. 1K resistor leg connects to your Battery (B+). Other leg of 1K resistor gets connected to "Anode(-) side of Zener diode. Cathode(-) Side of Zener diode connect to GROUND. (Voltage Regulator circuit complete at this point). Now you connect the Red wire(+) of the opener to the Cathode side of the Zenor Diode and the Black wire(-) of the opener to GROUND. Thus, there's a 9 volt drop across that Zener Diode. You just built a Voltage regulator circuit.

B(+) ----/\/\/\/-------|<------- GND(-)

or


If you find the range on your opener seems to be weak, then that means not enough current is being supplied to the opener and to fix this, you could further reduce the value of the resistor to say 100 Ohms instead of 1K. 1K is pretty typical though, where I don't foresee you having to change anything. The resistor regardless of it's value, drops anything that exceeds 9 Volts (The Value of the Zener) and additionally regulates the current that gets drawn through the circuit. Essentially, this is the same thing that Canibeat suggested in using a voltage regulator IC, but is cheaper and gives you control of how much current you would allow the opener to draw.

A Voltage regulator IC is really nothing more than the circuit I just outlined, except it is put in a nice little silicon package and costs more. Also if you open up and look inside one of those 9 Volt cell phone charges like suggested in Suggestion 2...chances are you will see a Zener Diode and a Resisor.

Notice how Canbeat outlined how the 7809 has 3 pin connections and the circuit I outlined also has 3 connections. Looking at the pic I posted above and comparing to what Canbeat mentioned. Pin 1 is where that "+" sign is shown, Pin 2 is at the bottom, and Pin 3 is right in the middle between that Resistor and Zener.

Cheers!!!

SynysterHD

Canibeat:
I appreciate the link, I will go to Radio Shack this weekend and see what my best options are

Rednroll:
Dang, Those are great instructions and I will attempt this project this weekend. I'm not sure I totally understand them yet, but I will read it over and over till I have it. I'm sure once I actually get it, I'll smack myself for not knowing how to do this in the first place. I've wired up plenty of race cars, but never had to use diodes and resistors, only relays.

Thanks to both of you, Canibeat and Rednroll. Hopefully one day I can be of some assistance to y'all!

Rednroll

Actually, when I was looking for an image on the Web to show the circuit I was describing, the web page I stole that image from was a pretty decent source for info.

Maybe you might find some of this useful:
Beginners Guide

Scrolling down to about the middle of the page, they go over the basics of that voltage regulator circuit.



How are you with understanding suspensions and lift kits?

I've been on this site for the past 2 years with a lot of enthusiasm to lift my JK for off road use. While I have learned quite a bit from reading in this forum, in all honesty, the more I learn...the more I get overwhelmed because, when I do something....I like to do it right and I like to understand why I'm doing it.

So, I have a lot of questions in regards to lifts that seems to be general knowledge for the offroad crowd and for those who have modded their JK with a lift. I've kind of been looking for a lift kit for dummies Q&A thread. Kind of along the lines of, "What is a rear slip differential.?...Where is it located? What does it do? Why do I need it? And what should I expect if I don't have one? And what would someone recommend as the best bang for the buck for an entusiast?

So if you know those kinds of things....then I just may take you up on that offer. When it comes to electrical stuff, I can hang with the best of them. When it comes to mechanical stuff, like lifts, drive trains and suspensions.....I feel as dumb as a rock.

JKatfish

Looks like a great mod, tho a bit complicated. For the simple minded like me, I just stick it under the roll bat padding over my left shoulder. Takes about 15 secs.

Rednroll

Lately, I've been keeping mine in the house. My wife and I had a new born baby last year, we started throwing all the new baby stuff we got in the garage. The next thing you know, the garage is filled with stuff and my JK no longer fits in the garage.....so no longer a need for garage door opener.

SynysterHD

I'm new to the jeep world, but I do know a bit about suspension and drive trains. Limited slip is designed to let one wheel spin if the other is in a bind, ie... turning or in rock crawling when one wheel is lodged on a rock and the other is still somewhat free, it will keep pulling. You need it on any street vehicle for daily driving, it make it a whole better drive compared to a posi-track rear, both wheels turn equally and when you turn on the street with a posi rear, the tire screech and your vehicle will jump like your in 4 low on the street in a 4x4. As far as best bang for your buck, I'm not familiar with the jeep mods yet so I'm not sure about that just yet... Don't feel dumb, we all started out knowing nothing about vehicles. The more you do yourself, the faster you'll learn.

SynysterHD

I thought about doing it that way, but decided to go this route.

Matthewd5

Very well done!

I love this idea and am going to play around with this mod tomorrow, thank you for the great write up and pictures!

Matthew