I've been in electronics for several years, and like everything else bringing the stuff I do for a living home brings it to life -

So I tinker with electronics from time to time...

If you have ever wondered about how to setup LED's for warning lights, or maybe wished you could shrink your idiot lights to a small warning panel off to the side, here is how you do that:

First off, what is an "LED"?
L.E.D. stands for "Light Emitting Diode". It's like a very small lightbulb, but it uses much less power. To connect them is a simple matter of figuring out how much resistance you need to put ahead of them to step the voltage down to what the diode can handle. They come in a variety of shapes and sizes, so they leave a lot up to the imagination and creativety of the person using them...


No matter what kind of box or enclosure you decide to use, or even if you want to mount the things directly into your dash panel (easily done) the first thing to think about is the style of LED you want for the job. Here is a picture of some common ones -

http://www.clubfte.com/users/greywolf/led.jpg

Big, small, round, rectangular, etc...

If you can solder, and cut and fit stuff - you can have a blast with these.

For example, you can use them for -

1) A headlight indicator
2) The oil sensor light
3) High-Beam indicator
4) Turn signal indicators
5) Back up light indicator
6) Air Conditioner pump indicator (tells you it's running or not)
7) Electric fuel pump indicator

~ The list is endless.....

The key though, is that all LED's have a voltage and current limit. The formula for figuring out what you need to match an LED to any voltage source is as simple as this:

50 to 75 OHM's, for every volt applied.
Ohms, as in a resistor (common nickle and dime part available from any electronics supply house. Radio Shack has some, but it's better to thumb through the yellow pages for a real store)

Here is a simple circuit diagram I drew up:

http://www.clubfte.com/users/greywolf/lediagram.gif

If you go with 50 ohms per volt - you will have a very bright LED, and I think it's best to tame them down a little to make them last.
My preference is to run about 1Kilohm of resistance ahead of them on a 12 volt system. First, to help them last much longer, and second because it's a pretty common part to find.

And now an example of the math:

12 volts, times 75 ohms, equals 900 ohms.

If I were dealing with house current -

115 volts times 75 ohms, would be - 8625 ohms, which I would probably 'round off' to about 9K Ohms....

Once you know this much, the fun begins!

You can mount them as many ways as you can imagine-
And I can imagine a lot...

All you need is a ground on one side, and whatever electric source you want to monitor on the other, be it headlights, your fuel pump, you name it!!!

In fact - you can take all of the major warning sensor signals and run them through diodes (ordinary ones) to a master caution light, if you want to do that. Each input would need a diode to keep them from going back out to the other signal lines, but I'll get to that one perhaps sometime later.

I hope someone out there has fun with this!!!


~ Wolf

 

One last thought -

You can have all of the dummy alarm stickers you want, but the major "tell" to a car or truck thief that an alarm is really installed, is the small blinking LED in the dash panel....

You did notice the blinking one I put in the above picture, didn't you?

Run a wire to a 12 volt source, and a hidden switch.
Then connect the switch to a 600 to 1,000 ohm resistor, and finally to a bright red LED in the dash panel.

When you park in a strange place, hit the switch, and the little light on the dash begins to blink - using practically no power to speak of.

Need I say more?

*winks*

 

Thanks Wolfie,
I've been meaning to do this for a long time.

Just in time for Christmas too.

Here's a wolf I found for you !

Dennis

78 F-150 429CJ C6 ,Silver w/Explorer Pkge
641/2 Mustang,Pre-World's Fair Car #8092
64 Fairlane S/C waiting for a 390-4spd.
68-Mustang.Sunlit Gold 80,000 miles
Attachments:

 

Great Idea and a Super article ... Worth adding it to the Tech Articles!!

__JOHN__:7

 

By all means!

Oh, and thanks for the Wolf -
He's even got his own barstool!
*L*

 

Very cool and just the source I have been looking for! Wolf, how difficult would it be to make LED tailights? I have been working on restomodding my 67 F100 for over 2 years. I would love bright lights in the rear, similar to the new Caddys. Those LED taillights really reach out and tell ya to hit the whoa pedal. Thanks for any ideas or advice. Mike

 

I would have to look a set of them over, to see what they did on them...

I forget how many milliamps flow through an LED, but it seems to me if you built an "ARRAY" of appropriately colored LED's, they could be connected to a single resistor, instead of one for each.

The total amperage would have to be figured, but I would be suprised if it was even close to a quarter amp...

Never tried multiple LED's in parallel - I'll have to think about that one...

It seems like it would take a LOT of them though.

 

Greywolf is indeed a kind and thoughtful gentleman.
I'd love to get that High Beam indicator out of my eyesight.


Guy's, those LED's used in the Tail lights are a different LED than the little ones used in small signal displays.
I called somebody, and found out the cost dang near a Dollar apiece.
That kinda shocked me so I gave up the idea of creating some new tail lights for my 77. My 5er needs better tail lights too.

There is a White version of that same LED thats used in small flashlights and such. Also expensive.

I'd like to make a Fiber optic network for the inside of the Cab. It's too dark for me. I'd like to light up the windo Crank *****, the Door handles and all the ***** and switches on the Dash with the Pale Phosperesent light. Just enough for my old eyes to find the things, and not enough to bother my eyes for night driving.

I got this stuff from a Publication Called "Nuts and Volts" and I also read "Poptronics" when I get the chance to read!
What do you guys read?

Keep this kind of info coming.

 

Sounds to me like you miss Las Vegas.
*grin*

How about a Cutout with the word STOP that lights up on each side at the back of the Truck when the brakes are activated?


Dennis
78 F-150 429CJ C6 ,Silver w/Explorer Pkge
641/2 Mustang,Pre-World's Fair Car #8092
64 Fairlane S/C waiting for a 390-4spd.
68-Mustang.Sunlit Gold 80,000 miles

 

The dash panel switches could be easily handled -

When using round LED's, drill a hole the same diameter as the LED, and glue them in from the back of the panel just above or below where the switch is located.

If you can find a small reostat (adjustable resister) with a 600 ohm minimum resistance, you can install it on one end of the panel near the light switches and connect one side to 12 volts at your panel light switch (so that it's only on when the other lights are).

Then use it as the power source for all of the LED's. This way, you have a dimmer control for all of them.

The other option is to go with illuminated switches - but ensure they are connected after the panel light dimmer switch. You may have to add a resistance to make the switches match the intensity of the panel lights though. Lighted switches will also draw a bit more current than an LED would, and I don't know what that particular circuit is rated at for sure...

The door and window handles present a different set of problems, because they move.

If the window cranks had clear or translucent end *****, I could see running a fiber optic strand inside the back of the handle, to holes at the ends that:

A) Picked up light from a bulb inside the door trim panel, and

B) Played the light that passed through onto the inside of the ****, so that it would light up.

The trim piece for the handle should be clear also.

That way there wouldn't be wear and tear on the fiber...

 

Thanks again Greywolf

On my 77, I'd planned to put a Phosper Ring around the window ****. Then run the Fibre Optic link from the source in the Dash, around through the Door wiring port and bring the end of it out just above the Regulator handle.
The difusion should just make the Phosper ring glow just enough to be seen in the Dark. No matter where the Handle was left.

Lighted switches are just too bright at night. I dont know what to do about them just yet.
Years ago My Dad brought home some switches from Greyhound, that had a little light in the end of the Toggle. They may have been the Phosper kind, and the Dim spot coming down on the dash from behind the drivers shoulder kept the glow going.

Somewhere in the industry there are switches like that still available.

What I'd really like to do is make the Dash all Digital, leaving it in it's original shape and size.

On your Led circuit, you could add a Cad Cell for dimming the LED at night. So the Resistance would become greater as it got darker. That way the LED would be bright enough during the day, and not so 'Pushey' at night, and a hands off operation.

 

Truckin' magazine had some adds for digital guages, and so does J.C.Whitney's.

I haven't checked yet, but I'm about to look around FTE to see if there are any OEM (original equipment) digital guages offered here. The requirement of course is to fit the original dash spaces...

Another point, is they would be useless at night if they were not illuminated.

I expect Ken has looked at these before, and there is likely to be a product source listed right here. If not, then it's possible that they may be something that can be special ordered using club connections; who knows?
It would depend on the level of interest. I wouldn't want FTE to get stuck with a group purchase that didn't sell...

It seems to me I also saw lighted switches on sale in the electrical sections of various auto parts stores, but they always seemed kind of flimsy to me. As in easy to break.

Truck stops on the interstate are a good source for a lot of this kind of stuff, and a good crawl through none other than your local yellow pages phone book may turn up an electrical supply house that has MUCH better prices than, say - "Manny, Moe, and Jack"...

Good hunting, man!

 

Cyberdyne Incorporated, out of Pennsylvania is the manufacturer of most of the digital guages I have seen for automotive applications.

But when you start talking about a combined Speedo/Odometer/Tach combo - LOOK OUT!

They're NOT cheap...

For one, they have Hewlett Packard guage elements in 'em.

The electrical systems and wiring forum has a note from me on this, so that a group search can be done.


~Wolf

 

I was going to just link to this, when I saw where 1ole4d asked about LED's on the forum, but naaaahhhhh...

In a little more depth -

There are several kinds of Light Emitting Diodes, based on what kind of light they emit.

Some are used for lasers, some for infra-red applications. They emit light both in and beyond the visual spectrum, and most TV remote controls have an IR LED in them.

In a TV remote, the LED is pulsed almost like someone sending morse code with a light bulb. The pulses are digital code though, and the TV set reads it and interprets the information.

There are also reciever diodes that can make an electrical signal when the IR light hits them. So there are all sorts of applications for these...

 

Thanks a bunch Wolf. Now I have a better understanding of LED's. I might have to start playing with them in the future



Please don't pull out in front of me! I can't afford to play "What's this?" with you or your car.