Lighting Help!!!!!!

Trekmanscott · Post by **Trekmanscott** » Mon Apr 11, 2005 6:57 am

I'm in a bind and I hope someone out there can help me. I'm in the process of building Ertl's Defiant. I'm building the model so that it light's up. I wired 15 LED's of differing colors inside the model. two of the lights are connected to a 4060 chip so that they blink. Here's my problem. Everything was working just fine when I glued the 2 halves of the model together. Yesterday After I laid down the base coat I removed the paint masks and reconnected the wiring to do a light test and to check for light leaks. Only 1 of the 2 LEDS on the 4060 chip will blink! I have no idea what could be wrong. I'm leaning towards the fact that I need a new battery. The 1st LED in the series will blink, so i'm thinking that there's not enough power in the battery to light the second LED. I can't reopen the model. I used epoxy to glue the aftermarket parts into place. Anyone have any idea what could be causing this, and have any ideas on how I could fix this. I can't reopen the model. I used epoxy to glue the aftermarket parts into place.

Scott Hasty · Post by **Scott Hasty** » Mon Apr 11, 2005 9:54 am

I'm 99.999999% certain it's not a power issue. I'm equally certain you have a bad connection. Did you solder all the joints?

Scottie

Trekmanscott · Post by **Trekmanscott** » Mon Apr 11, 2005 10:10 am

I did not solder. I used a wire wrap tool for all of the connections. The whole thing is bizzare. Any suggestions on how to fix it?

rossjr · Post by **rossjr** » Mon Apr 11, 2005 10:49 am

It could be power but it would be better to see a schematic of what you wired. I am concerned that the LED's are in series when I think they should be in parallel, maybe it's just the wrong term you used but it sure would help to identify the problem.

Scott Hasty · Post by **Scott Hasty** » Mon Apr 11, 2005 1:31 pm

Trekmanscott wrote:I did not solder. I used a wire wrap tool for all of the connections. The whole thing is bizzare. Any suggestions on how to fix it?

Well, that brings me to believe you have a broken connection. If it were power, your other LED wouldn't operate (as well as your CMOS chip). Short of cracking it open and fixing it, I cannot think of any other way of getting to it unless you want to cut (or drill) through the area you think the proplem is in.

Scottie

MarkW · Post by **MarkW** » Mon Apr 11, 2005 2:06 pm

I gotta agree--your best best may be to cut it open in an inconspicuous place and try fixing it.

In general, soldering is my preferred way to go. It is a gaurunteed joint.

Sparky · Post by **Sparky** » Mon Apr 11, 2005 2:25 pm

It is possible that the power is to low to light one light, In fact on Neil's tug there are a red and green led on either seid for nav lights, they are hooked in parallel to the driver circuit but have their own dropping resistor. Since they have different voltage ratings as the battery gets low you can hardly see teh green blining while the red is still visibile. But if the hole thing isn't noticebly dimmer then you probably have a bad contact connection. Also if epoxy or something else managed to get onto a connection that wasn't sodlered it may have isolated the wires enough to brake the electrical connection.

Post by **LindaSmile** » Mon Apr 11, 2005 2:32 pm

Try reversing the polarity.... sorry, I couldn't help myself.

Linda

Trekmanscott · Post by **Trekmanscott** » Mon Apr 11, 2005 7:43 pm

OK well I bought new batteries and I put them in no good. So I took mark and scott advice and I cut open a smaller area on the model and for some reason the LED was bad. I have No idea what happened to it. Well after about a half hour the LED was replaced and I'm ready to seal the hole. I guess I lost a couple day on this 1 LED but I guess it better that it happened now and not in Louisville

A freaid thought that maybe the gass leaked out of the LED. Who knows. Well I have to go fill in the new "door" I added to the Defiant.

Thanks for the help guys.

rossjr · Post by **rossjr** » Tue Apr 12, 2005 8:54 am

Please tell me that you have a resistor in series with the LED, if not you will be replacing a lot LED's frequently...

Balok · Post by **Balok** » Tue Apr 12, 2005 7:30 pm

Yup, and use solder after you wirewrap.

I use this all the time.
<A HREF="http://ourworld.compuserve.com/homepage ... d.htm">LED Series Calculator</A HREF>

en'til Zog · Post by **en'til Zog** » Wed Apr 13, 2005 4:03 am

If the LEDs are being driven by an IC like the 4060, they're safe enough with no resistor - even if the chip is being fed 9 volts. I've been using them that way for years, no ill effects to the LEDs.

That's the nice thing about using CMOS chips - the output is 11 milliamps max - safe for any LED. And no, I've never had trouble with the 'excess voltage'. It seems to be the amperage that fries the LEDs rather than too much voltage. IF the amperage is kept down things seem to be fine.

My experience. Your mileage may vary.