Illuminating gauges with Electroluminescent tape

[DanLewis]

I thought people might be interested to see how I've changed the illumination of the gauges in my Bugeye using a product called Electroluminescent tape (or simply "EL tape"):

Details are posted in the "Articles" - click here.

Enjoy!
Dan

 

[George Zeck]

Any heat concerns?

 

[DanLewis]

Any heat concerns?

Not at all. The EL Tape is cool to the touch, as is the inverter. I think the whole package consumes quite a bit less power than the four incandescent bulbs that it replaced.

Dan

 

[Trevor Jessie]

What is the service life expected?

 

[DanLewis]

Hi Trevor,

What is the service life expected?

Good question. I've only had it installed a couple of weeks, so I really don't know. However, at least there's no incandescent filament to burn out. Except for the holes I had to drill in the tach and speedometer cans, it should be easy to undo the modification and reinstall the original lights. However, my guess is this will outlast them. I believe it's the same technology that a lot of modern cars now use to light their dash.

Dan

 

[JPSmit]

can you say more about how you installed it? looks great BTW

 

[DanLewis]

Hi John-Peter,

can you say more about how you installed it? looks great BTW

Thanks! I restored the details back into the original post for now. As soon as Basil publishes the article, I'll replace the details with a link to the article to avoid duplication.

'Hope that helps.
Dan

 

[JPSmit]

it does Dan thanks!

 

[58Custom]

THIS is freakin' brilliant! Ima gonna do this!

 

[Boink]

I'm already thinking TOILET SEATS... for the groggy late-night visit.

 

[JPSmit]

I'm already thinking TOILET SEATS... for the groggy late-night visit.

How are you going to get toilet seats in your instrument cans? Oh, wait a minute you mean how do I get my can on the toilet seat....

 

[58Custom]

Dan,

The kit sold in your link is for a five foot strip and an inverter to power it with 12vdc in. When you cut a single 5 foot tape into pieces, you can hook up the pieces end to end and power the pieces from the one inverter, correct?

Nevermind. I was thinking your direction to connect multiple pieces in parallel sounded off but research has shown you are correct. This link shows the same:
https://www.lighttape.com/library/DesignGuide/Connecting_Multiple_Segments.pdf

So I plan to connect the multiple pieces in parallel. The method of lead attachment in this Instructible will work but I plan to bring the leads back over the tape and secure & insulate with RTV for a compact install. As for clearance with the dash holes, I can construct the loops of tape on the gauges and then push them off, load then through the hole, load the gauge and slip them back on. I will secure them onto the gauge with some kapton tape. What's a few more scars on my hands from the back of the dash if I can get my gauges lit once and for all, eh?

Also, conductive glue. Might be easier than soldering for some. All is not far from me, might be something to try.

Hey, does the inverter or the lead from the inverter induce noise in the radio?

 

[DanLewis]

HI Tom,

Dan,

The kit sold in your link is for a five foot strip and an inverter to power it with 12vdc in. When you cut a single 5 foot tape into pieces, you can hook up the pieces end to end and power the pieces from the one inverter, correct?

You can put them end-to-end (serial) or in parallel - it doesn't make any difference. The tape has two wires in it that run the length of the tape in parallel. To the inverter power source, the tape simply looks like a capacitor. Adding more tape in parallel or in series simply increases the amount of surface area of that capacitance.

While the article you reference claims that parallel is preferred because serial connections cause heat to build up at the connection points, I don't think that would happen with the tape I used. The article is about tape that was MUCH wider and MUCH longer than the kind I used. Mine consumes so little power that there's virtually no heat generated at all - the tape AND the inverter are cool to the touch.

Hey, does the inverter or the lead from the inverter induce noise in the radio?

I'm afraid I wouldn't know - there's no radio in my car.

BTW, the reason I used four 5' tapes and cut each one to a much shorter length was the frustration I ran into trying to solder wires to the extra tape I had cut off. I followed instructions I found on the Web that said to stick copper tape to the EL tape and then solder to the copper tape. While I had no problem soldering to the copper tape, the real problem was that the two conductors in the EL tape are not the same width. One of them was very narrow (maybe 1/16"), while the other occupied the remaining portion of the 1/4" wide tape, and the two conductors were this way all the way down the tape until it got to the end where the original wires were attached by the factory. Getting a connection to that 1/16" conductor was something I won't try again.

Dan

 

[dklawson]

That is super neat!

I had considered buying strip LEDs off eBay to try something similar but this looks more uniform and "clean". Nice job!

Am I correct assuming that there is no method of "dimming" the light if you find it a bit bright?

 

[DanLewis]

That is super neat!

I had considered buying strip LEDs off eBay to try something similar but this looks more uniform and "clean". Nice job!

Am I correct assuming that there is no method of "dimming" the light if you find it a bit bright?

Thanks for the kudos!

I haven't considered whether or not it is possible to dim the light - partly because it seems just about right to me the way it is. You might try lowering the input voltage to the inverter, but I don't know if that would make a difference. It might stay the same brightness until the voltage got low enough that the phosphor was no longer excited and stopped giving off light.

I did, however, find this inverter that runs off 9v and has adjustable brightness:

https://www.ebay.com/itm/281070275668?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

Dan

 

[58Custom]

Variations in small gauge housings complicate things.

I received my el tape and inverter this week. Yesterday I started gathering up old gauges to look over the application areas. Neither the fuel gauge nor the oil/temp gauge installed in the car have the windows that yours do and my old broken oil/temp gauge does. I assume that the current oil/temp gauge will have room to add the tape around the internal circumference of the gauge housing as is done with the tach and speedo. However the fuel gauge has a two-piece face assembly using a face trim plate over the face plate itself and that face plate is inset. The width of the area between the pieces is about .25 inches and the tape is approx .375. I will have to see if trimming the width of the tape is possible and if it affects the performance of the tape to an unusable degree.

To get the wires around the various gauge bits in the oil/temp gauge I will have to source some rather fine and flexible wire.

For my first experiment, I have cut a small piece of el tape and have peeled back the plastic covering over the two grey traces. To get the 1kHz signal to the tape I am first trying Nusil CV2-1148 conductive adhesive. Once this cures I will wrap it with kapton tape and then shrink wrap and test. It is currently curing.
For the second experiment I cut another strip and using scissors I slit it to the width required for use between the face plates of the fuel gauge and tested it. It works, so now I have to find a way to insulate the exposed edge of the phosphorus strip (prolly some clear RTV).

 

[DanLewis]

The width of the area between the pieces is about .25 inches and the tape is approx .375.

I think I've seen narrower tape listed by a distributor in China, but I certainly haven't found it anywhere at retail. FYI, the first time I tried to use the tape on the smaller gauges, I did something similar - I trimmed the width and placed it inside the gauge. I think the only reason I ultimately chose to put it on the outside instead was that I didn't have to trim it or worry about the trimmed edge.

It's curious that your smaller gauges do not have the windows to let light in as mine do. I presume that means that the original incandescent bulb was not mounted external to the gauge, but perhaps was inserted into the back of it somehow? Are your gauges made by Smiths, like mine?

It sounds like you have found solutions to these challenges. Keep me posted on your progress (and pictures too)!

Dan

 

[58Custom]

Dan,

Pix to follow eventually.

I have a MKIII Midget with Smiths gauges and I have a Smiths fuel gauge pulled from a MKIII in a wrecking yard. Neither have the windows so this is a real variation.
Yes, the Smiths oil/temp and fuel gauges use internal bulbs inserted into bulb tubes on the back like the speedo and tach. Like this.

Just tested the strip with the wires glued with CV2-1148 conductive adhesive. No workey. One side shows continuity from end of wire to phosphorous strip but the other side does not. Infinite resistance between wire and adhesive blob. Seems if the bared wire is touching the phosphor the glue keeps it there but if the wire has moved away from direct contact with the phospor the impedance of the cured adhesive is too high to pass current. So the CV2-1148 is out. That's OK, the sample was free.

Next week I'll get over to an electronics store for some Wire Glue and some fine, flexible wire and some small connectors. Also, folks are soldering this stuff so I will try that as well.

 

[DanLewis]

Just tested the strip with the wires glued with CV2-1148 conductive adhesive. No workey. .

You might try soldering to copper tape, but be sure to get the kind with conductive adhesive, like this.

Dan

 

[58Custom]

You might try soldering to copper tape, but be sure to get the kind with conductive adhesive, like this.

Dan

OK, just bought a piece. I know how I will use it to contact the thin trace sufficiently but securely. Hopefully I will be able to show a fuel gauge install next weekend. Fun stuff!