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LED lights and static

W

wings05rv6a

Active Member
Hello everyone,

I have been flying my RV6a for several months now. :p My wife has to smack me in the head after every flight to "GET RID OF THAT GRIN".

I do have a question regarding my home made LED marker lights. They are very powerful and put out a tremendous amount of light. Unfortunately they also create static in our head sets. I sure would like to use them more. Does anyone have any ideas of what I should do?

THANKS
BOB WIECZOREK.
 
Spruce has some LED lights glued into a socket base to replace wingtip NAV lights. They are old school individual LED bulbs. The problem with just cludging together a bunch of bulbs, is RF radiated noise as these threads have shown. One particular color.... I recall it being the green one.... would wipe out several frequencies on a com radio during tests I did. The companies like Whelen and Aeroleds charge more for their products, but they are sure tested more. The loose collection of bulb concept will probably disintegrate in time as well, due to vibration. Now, truth be told... I found a nice aluminum housed set of off road lights from China that fit nicely out in the wing of my 9A. Bright enough to land with and quiet on the radio. The rub is, you have to be willing to trash them if the testing shows a problem. So you may save, you may lose.
Some of the imports are cheap enough that it is just fun to try them out. Other times... you want to spend the money and just get the tried and true. Now, for the certified crowd...the FAA has been making it very expensive for manufacturers to get approvals. And slow.... SLOW. Which is quite frustrating since the nature of LED's is so simple. Cooler, less current and long lived. Bless the FAA, they are going to keep us from harm.
 
flightlogic said:
. Now, for the certified crowd....
Click to expand...

Remember that if you are flying at night your EAB operating limitations/FARs require you to use "approved" position (nav) lights and anti collision light(s).
Most interpret that to mean that while your lights do not need a TSO, you must show that they meet the brightness and coverage requirements.
 
Not sure what you are driving your LEDs with. It sounds like you have an LED controller of some type. Most LED controllers use constant current and a PWM (pulse width modulated) signal to adjust the brightness or to control the amount of power dissipated in the LEDs. This PWM signal is switching on and off and its this switching that can cause noise. If you measure the current draw with a meter you will see the average current, but in fact it is switching on and off. To look at what is actually going on you would need a current probe or some way to sense the current.

The answer to your question is you need a power filter so that this pulsed current is not conducted into your power wiring or coupled into some other wiring. For production LED lights they are aware of this problem and they would normally include some level of filtering in the design.
 
Search for Pete Howells LED position lights. A resistor won't make noise no matter what color LED ( or frequency).
 
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