Best high CRI LED for 12V RV? Thinking of hacking up L-prize as donor

carnal · Jun 17, 2013

Knowledgeable ones...

My brother and wife are going full time RV'ing and have sold their house. I'd like to give him a send off gift of a few high CRI lamps for his 30' trailer. I gave them a L-prize a few months ago, and they were wildly excited. They run it off shore power 110V, when near a RV park, or off a REALLY tiny inverter when on battery power. I Know HUGELY inefficient and perhaps torturous to the L-prize's power supply.

I've seen some of the MR-16's that might work. http://www.soraa.com/technology/quality has a $30 12v ac or dc MR-16 lamp that has a 95 CRI.

But even better idea I think is using my stock of $15 L-Prize Phillips lights, tear a couple apart and use the 3 individual faces of the alien head assemblies, to make up 3 individual RV ceiling lamps. I really like the idea of those soft remote phosphor illuminators. The Guy that did a really nice tear down of the L-prize
http://www.molalla.net/members/leeper/L Prize Bulb/L prize bulb.htm
The author said this lamp uses 3 watt LED's under driven to aprox 1/2 watt each. He also said all 9 led's in each channel (blue and red) were in series. Taken apart I'd have 3 blue in series and 3 red in series for each illuminating face.

Thinking these are Royal Philips LumiLEDs Luxeon Rebels, what does this mean voltage wise, if I'd have 2 channels 3 each in series? Is there enough head room voltage wise with 12V driving it. I'd have to calculate a dropping resistor for each channel, if so. They do let their batteries drain somewhat when they have restrictions in Nat Parks. But I'm unsure to what level.

Also I'd have to figure a way to keep them heatsinked and open to airflow.

Any ideas on this or any other creative ideas in hacking up off the shelf lamps? Or are there any single discrete LED emitters, that would compete price wise with my cutting the $15 purchase price in 3 (one $15 lamp becomes 3-$5 lamps) plus a dropping resistor?

They probably WON'T be sold on a low CRI solution.

Also I need really simple ideas to dim the hacked alien head faces of the Franken-Phillips led assembly, if this whole idea is even possible.

I REALLY appreciate all of your knowledge!

Thanks Brian

SemiMan · Jun 18, 2013

carnal said:
Knowledgeable ones...

My brother and wife are going full time RV'ing and have sold their house. I'd like to give him a send off gift of a few high CRI lamps for his 30' trailer. I gave them a L-prize a few months ago, and they were wildly excited. They run it off shore power 110V, when near a RV park, or off a REALLY tiny inverter when on battery power. I Know HUGELY inefficient and perhaps torturous to the L-prize's power supply.

I've seen some of the MR-16's that might work. http://www.soraa.com/technology/quality has a $30 12v ac or dc MR-16 lamp that has a 95 CRI.

But even better idea I think is using my stock of $15 L-Prize Phillips lights, tear a couple apart and use the 3 individual faces of the alien head assemblies, to make up 3 individual RV ceiling lamps. I really like the idea of those soft remote phosphor illuminators. The Guy that did a really nice tear down of the L-prize
http://www.molalla.net/members/leeper/L Prize Bulb/L prize bulb.htm
The author said this lamp uses 3 watt LED's under driven to aprox 1/2 watt each. He also said all 9 led's in each channel (blue and red) were in series. Taken apart I'd have 3 blue in series and 3 red in series for each illuminating face.

Thinking these are Royal Philips LumiLEDs Luxeon Rebels, what does this mean voltage wise, if I'd have 2 channels 3 each in series? Is there enough head room voltage wise with 12V driving it. I'd have to calculate a dropping resistor for each channel, if so. They do let their batteries drain somewhat when they have restrictions in Nat Parks. But I'm unsure to what level.

Also I'd have to figure a way to keep them heatsinked and open to airflow.

Any ideas on this or any other creative ideas in hacking up off the shelf lamps? Or are there any single discrete LED emitters, that would compete price wise with my cutting the $15 purchase price in 3 (one $15 lamp becomes 3-$5 lamps) plus a dropping resistor?

They probably WON'T be sold on a low CRI solution.

Also I need really simple ideas to dim the hacked alien head faces of the Franken-Phillips led assembly, if this whole idea is even possible.

I REALLY appreciate all of your knowledge!

Thanks Brian

Depending on the switching power supply design, a square wave or pseudo square wave inverter is really not that bad for it if at all. Diode bridges certainly do not care and even the detection for triac phase angle may work better.

My 100W cheapy inverter only draws about 1 watt without any load, and hits 90%+ efficiency when running. The cheap ones are often more efficient than the fancy sine wave versions as there is less switching losses.

They may be just fine with L-Prize bulbs without any issues at all with the small inverter. The total load is not bad at all.

You can get Soraa high CRI MR-16 without any hatchet job. Note they do have some deep blue spike in them, but should not be an issue most of the time.

Semiman

EngrPaul · Jun 20, 2013

I've been considering using the bulb as a driver and extending the wires to the LED boards. The boards I would attach to an aluminum plate, then I clip the phosphor lenses on. The resulting assembly I would use to replace my over-cabinet utilitech bars. I bounce the light off the ceiling to light the office and the bars I have now have never really been bright enough for the power they consume.

carnal · Jun 22, 2013

EngrPaul said:
I've been considering using the bulb as a driver and extending the wires to the LED boards. The boards I would attach to an aluminum plate, then I clip the phosphor lenses on. The resulting assembly I would use to replace my over-cabinet utilitech bars. I bounce the light off the ceiling to light the office and the bars I have now have never really been bright enough for the power they consume.

I sort of hate to think of making Franken-L Prize contraptions. There's a risk high cri 94Lumens/W lamps will EVER be manufactured again, and they'll go up in value like gold. Can't believe Philips quit making it. And WHY did Home Depot dump them at $15? Boggles my mind. I guess only a few know their real value. I guess what made those 18- 3 watt led's so efficient is they were WAY underdriven at 1/2 W. Remote phosphor is coolness!

Anyway if you separate the L-prize emitter boards from the driver you could def keep them MUCH COOLER with larger heat sink's. When opened up you could put them on a double throw switch and put them on battery back up for power failure mode.

Do you think 12v would drive the 2 L-prize's '3 leds in a series' channels?

AND instead of throwing away, you could take your Utilitech bars and bend them up unto...

Franken Utilitech / Battlestar Galactica helmet. While you are at it.

EngrPaul · Jun 23, 2013

carnal said:
AND instead of throwing away, you could take your Utilitech bars and bend them up unto...

Franken Utilitech / Battlestar Galactica helmet. While you are at it.

These pictures bring back memories of my childhood. But I don't remember Lorne Greene's cowboy hat having LED's???

yuandrew · Jun 23, 2013

Judging by the chart on Page 2 of the Philips Award Winning LED Bulb Review thread ( http://www.candlepowerforums.com/vb...4-Philips-Award-Winning-LED-Bulb-Review/page2 )

I'm thinking I'd try 6 volts on the three reds in series and 8 volts on the three blues in series (one board) to start.

I had a similar project back in 2011 for a friend's Popup tent trailer using the Bridglux BXRA-W0402 and a Thinlite 312 fixture (common in Fleetwood RVs) for my host. Ran both them at 700ma and it was more than bright enough (with the clear lens, it blinded you if you looked at it; had to find the white, diffused lens instead) The remote-phospor design of the Philips would help.

carnal · Jun 24, 2013

yuandrew said:
I'm thinking I'd try 6 volts on the three reds in series and 8 volts on the three blues in series (one board) to start.

I had a similar project back in 2011 for a friend's Popup tent trailer using the Bridglux BXRA-W0402 and a Thinlite 312 fixture (common in Fleetwood RVs) for my host. Ran both them at 700ma and it was more than bright enough (with the clear lens, it blinded you if you looked at it; had to find the white, diffused lens instead) The remote-phospor design of the Philips would help.

What LED voltage value are you going to use in the formula for a dropping resistor?

.....Es - E led
R= _______
..... I led
where:
Es is the source voltage, measured in volts (V),
Eled is the voltage drop across the LED, measured in volts (V), IN OUR CASE it would be times 3
Iled is the current through the LED, measured in Amperes (Amps/A), and
R is the resistance, measured in Ohms (Ω).

Or are you limiting current some other way?

Back to the limiting resistor formula--do you know what the drop is across each luxeon style of LED in L-Prize?
If you are guessing 6 and 8V for each set of 3, yep probably not enough head room to run 2 boards in series (6 total leds) especially knowing the RV/trailers voltage will be dropping as the bat discharges.

I guess one could measure the actual V drop after hacking L-Prize open.

I looked up your Bridglux Leds. They are array's right? Im not familiar with arrays. They said the typical forward voltage is anywhere from 9.5-28V depending on model.

Interesting... hmmm
whats the best cri you can get in a warm white array like this? 82 or so?
And there is lumens per watt to think about, in an RV running on batt power.
I see what you mean being BLINDING, tho. 400 lumens as a small single source light spot. Arc welder!

Thanks for your input!
Brian

The more I think about it, my idea of controlling current with dropping resistor could be pretty wasteful, to a storage battery.

yuandrew · Jun 25, 2013

The Bridglux are arrays in the sense that under the yellow phosphor, there's a bunch of individual LED "chips" in series with a vF that adds up to the total forward voltage of the entire assembly. The one I used have a CRI of 82 and a vF of 9 volts. Bridgelux does have some with a CRI of 90 but they all have a forward voltage higher than 12 volts; most were 18 to 25 volts.

I used constant-current LED drivers (BuckBullet from LED supply) in my project instead of a resistor. Keep in mind your source voltage in an RV can vary anywhere from 14.8 volts with the converter/alternator charging to 11.8 volts if you let the battery run down while dry-camped. With a fixed resistor, the drive current through the LED array will vary with the battery voltage. A constant current driver will keep feeding the LEDs with a steady amount of current (700ma in my case with the Bridgelux array). It will keep the LEDS running at the set current as long as the supply voltage is at least two volts higher than the total forward voltage of the LED string or array.

As for using the arrays from the L-prize bulb, the thread I linked to has a post with a chart that shows the forward voltage of the red and the blue LEDs at different drive currents ( http://imageshack.us/a/img803/5985/redandbluepeaks.png ) The lowest on the chart was 350ma which would be a forward voltage 2.150 volts each for the RED and 2.832 for the BLUE. Since the L-prize bulb under-drives its LEDs below that, I just figured I'd take off a couple millivolts (just guessing, don't have a voltage/current relationship chart) and try 2 volts on the RED and 2.67 volts on the BLUE. Multiply the numbers by 3 since since there three of each color in series on one board to get the total vF of each LED string (6 volts for the REDs and 8.01 volts for the blues). Then just try those values out while measuring current and adjust until you get what you want.

luxdelux · Jul 7, 2013

carnal said:
Knowledgeable ones...

My brother and wife are going full time RV'ing and have sold their house. I'd like to give him a send off gift of a few high CRI lamps for his 30' trailer. I gave them a L-prize a few months ago, and they were wildly excited. They run it off shore power 110V, when near a RV park, or off a REALLY tiny inverter when on battery power. I Know HUGELY inefficient and perhaps torturous to the L-prize's power supply.

I've seen some of the MR-16's that might work. http://www.soraa.com/technology/quality has a $30 12v ac or dc MR-16 lamp that has a 95 CRI.

But even better idea I think is using my stock of $15 L-Prize Phillips lights, tear a couple apart and use the 3 individual faces of the alien head assemblies, to make up 3 individual RV ceiling lamps. I really like the idea of those soft remote phosphor illuminators. The Guy that did a really nice tear down of the L-prize
http://www.molalla.net/members/leeper/L Prize Bulb/L prize bulb.htm
The author said this lamp uses 3 watt LED's under driven to aprox 1/2 watt each. He also said all 9 led's in each channel (blue and red) were in series. Taken apart I'd have 3 blue in series and 3 red in series for each illuminating face.

Thinking these are Royal Philips LumiLEDs Luxeon Rebels, what does this mean voltage wise, if I'd have 2 channels 3 each in series? Is there enough head room voltage wise with 12V driving it. I'd have to calculate a dropping resistor for each channel, if so. They do let their batteries drain somewhat when they have restrictions in Nat Parks. But I'm unsure to what level.

Also I'd have to figure a way to keep them heatsinked and open to airflow.

Any ideas on this or any other creative ideas in hacking up off the shelf lamps? Or are there any single discrete LED emitters, that would compete price wise with my cutting the $15 purchase price in 3 (one $15 lamp becomes 3-$5 lamps) plus a dropping resistor?

They probably WON'T be sold on a low CRI solution.

Also I need really simple ideas to dim the hacked alien head faces of the Franken-Phillips led assembly, if this whole idea is even possible.

I REALLY appreciate all of your knowledge!

Thanks Brian

I would be take caution if trying to hack and piece together some LEDs, especially in an RV. Some LEDs without the proper heat sinks can run really really hot.

Best high CRI LED for 12V RV? Thinking of hacking up L-prize as donor

carnal

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SemiMan

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EngrPaul

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carnal

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