http://ledbulbs4less.wix.com/ledbulbs4less

Quote:I'm a bit of a techy and after years of changing LED bulbs on first my trailer and boat, I helped family with theirs, then friends and now I want to help you change over to LED bulbs in your rv or Boat. I'm always watching and researching the changing technology of LED bulbs and it changes every year.
The first one I put in my trailer, I was dissapointed with the light output.
But NOW the light output is the same or greater using 10% or less of the current bulbs used.
This makes dry camping more comfortable not having to make sure all the lights were off all the time since the draw is so little. Leave that 1 watt bulb on outside without worrying about killing your valuable power reserves in your batteries. Also with almost no heat production, you know that you are not damaging any plastic fixtures in your unit by leaving them on for a good length of time.

Good morning, Doug;

I have also been converting the lighting inside -- and outside -- my motor home to the new LED lights, but it came with a surprise.

I noticed that a lot of the lights that I had installed inside the coach body were not making it past even a SIX (6) week time period before they were dying during some testing that I was running.

This problem was because of the old design (can I use that term in connection with what is truly a completely inadequate product?) of the "12 VDC RV power converter" from the 1960s, but they were still putting them into RVs through the 1990s. That old design is more related to economics than to any technical considerations. Basically it is merely a center-tapped transformer secondary and a pair of diodes to provide a full wave rectified pulsating direct current waveform out to the "12 VDC" circuit of most of our older motor homes.

Please note that this problem is seen only when plugged into "shore power," or when running the 120 VAC generator. The actual problem is that this "pulsating DC waveform" from the "power converter" is not the stable straight line voltage level "12 VDC" that we think of with a battery. It is a widely varying voltage that rises from Zero Volts up to a real 18 Volts Peak at the top of the waveform, and it is that 18 VDC peak voltage that was destroying my LED lights inside the motor home. I have photographs of the oscilloscope trace that show this offending waveform. Yes, the "average" voltage was in the 13 VDC range, but the 18 VDC peak was killing the LED lights.

I can say that the LED lights by the Star Lights people do have a built-in voltage regulator in their LED lights, and they really do work fine on the older "12 VDC RV power converter," but they are also noticeably more expensive. If you are putting in only a few LED lights, that may be a more cost effective way to go. Just remember that the old "power converter" is still not very good for computers, radios, cell phones, and other similar things.

If you still have the original instructions that came with your "12 VDC RV power converter," and the instructions say to measure the output voltage with "a true RMS reading" digital volt meter or digital multi meter, that is a very reliable indicator that you have the old disgustingly simple early and still inadequately designed "power converter" in your motor home. I do not recommend putting in LED lights or trying to run our modern computers, radios, cell phones, GPS navigation systems, and other electronics equipment off such a "power converter."

My cure was to replace the original "power converter" with a real true "POWER SUPPLY" with filtering and voltage regulation that puts out a specified 13.8 VDC with a voltage range limit specification of about +/- 0.2 VDC from no load to full load. There is also a "noise and ripple" specification of " 50 mv or less" on the output. Two that I can think of right now are the Power Dynamics PD-4600 or PD-46xx series, or the WFCO 8900PEC series, and some others. The main thing is to look at the voltage output specifications for the 12 VDC coach electrical circuit, and not the numbers for the battery charging part.

These new "power supplies" seem to be developments off the switching mode power supplies commonly used with desktop computers, so they are fairly mature and reliable.

I will note and advise on how my conversion to LED lights is going, and if I see anything in the way of "radio noise" (RFI) coming from the new switching mode power supply, or from the new LED lights also. The Anritsu MS-2711B portable spectrum analyzer is very good for tracking down noise sources.

Enjoy;

Ralph
Latté Land, Washington

for info...

http://www.bestconverter.com/W...53.html#.VvFhLcybQps


http://www.amazon.com/Progress...?tag=duckduckgo-d-20

Thanks for the LED bulb link. It's just up the road a bit.