LED Nav lights

[apatti]

I have researched past posts on LED nav lights and have a few questions. First, for those of you that have installed them:

1) Did you buy a kit from someone or roll your own?
2) Did you have any trouble with your DAR not wanting to certify your aircraft for night flight? Did you have to provide any test documentation?

Second, for any DAR's out there that have inspected aircraft with LED nav lights?

3) What, if anything, did you require from the builder to "prove" compliance?

As you can guess, I really like the idea of LED nav lights and would even feel comfortable rolling my own. I just don't want to have trouble with the inspection.

Thanks in advance...

[RV7Guy]

Hi Tony,

I have the Creativeair LED's, an early version. I built them and have never built anything electronic in my life. No big deal.

Now they have more improved versions that fit in the tips great.

In most cases the LED's exceed the FAA requirements. My DAR looked at them briefly and simply commented on how they should last longer than regular lights.

Use them with confidence. The Creativeair package is very reasonably priced. Hardly worth the time you could be building to research a do it yourself package.

[Norman CYYJ]

LED's work very well. But some of the constant current drivers for them are very noisy. The noise is hard to detect in the radio's but will show up by cutting the receivers range down by quite a bit.

[chaskuss]

I have a set of the conventional Grimes style position lamps. I know that manufacturers have created LED bulbs using standardized bulb sockets so that you can install LED bulbs into lamps built for standard incandescent lamps. Has anyone built an LED bulb for the Grimes style lamps?
Charlie

[apatti]

Originally Posted by Norman CYYJ

LED's work very well. But some of the constant current drivers for them are very noisy. The noise is hard to detect in the radio's but will show up by cutting the receivers range down by quite a bit.

Sounds like they may be emitting broadband RF energy that gets into the receiver's AGC (automatic gain control) circuit. Has this been documented? Anyone else have this problem? Is the degree of the problem related to the distance between the drivers and the antennae?

[Brantel]

Originally Posted by Norman CYYJ

LED's work very well. But some of the constant current drivers for them are very noisy. The noise is hard to detect in the radio's but will show up by cutting the receivers range down by quite a bit.

Follow the directions for the constant current source and this problem is minimized or eliminated. A filter cap is all that is needed to shunt the noise.

If if is that big of a problem, run as many in series as you can and then use a resistor to fine tune the remaining voltage drop and then you have a totally passive system with no noise potential whatsoever.

[Jeff R]

Some LED current drivers work by chopping the input voltage. This allows the LEDs to be run at max peak current to obtain max brightness but with less power loss. The current switching can generate radiated noise unfortunately. A filter capacitor at the LED end of the power leads might help. Maybe try a large electrolytic in parallel with a small ceramic capacitor. The large capacitor will even out the current spikes in the power leads, and the small capacitor will filter out the higher frequency noise that the large capacitor can't. As was said, you could simply use a series resistor and then there shouldn't be any noise problem at all, but the power losses will be higher and the life of the LEDs might be reduced.

[mannanj]

apatti:

Check your PM's

[frankh]

Works great, no noise and the DAR said.."Woah, they are BRIGHT!"

Frank