12v LED cabin lights

[markpj23]

Originally Posted by bstreep

I'm in the process of replacing about 12 fluorescent fixtures in our boat with LEDs. I'm using the current "state of the art" Luxeon Rebel LEDs, along with a regulator for each of the fixtures...

Do you have info / source for the regulators? FYI I found a source for the Luxeon LEDs already mounted to a PCB. Adding a regulator would create an equivalent setup at lower cost perhaps...

Super Bright LEDs - Light Bars

[Alan Wheeler]

Actually if you are going to use one regulator for all of the boats lights then you need to use a fixed voltage regulator because as you turn circuits on and off the required current will vary.

Let me say this again. This is very important to understand. Voltage is of no importance. LEDs are Current operating devices. You must regulate current.
Wimsical, if a boat has been wired correctly, all lighting circuits should be in parrellel. So turning on or off a light or LED should not alter current. Unless it is such a powerfuly hungry current sucking device that it pulls down the batteries ability to supply the current.
However, you are on the right path that volatage will indeed vary. There will be a variation of many volts between a discharged battery and a battery in absorbtion charge for instance. Maybe as much as 4Vs. But once again, it is the current that needs to be regulated. And the regulator circuit needs to be able to handle that voltage range and als maintain a constant current over that range and for the load placed upon it by the lighting.

[bstreep]

Mark, I'm not sure, but reading the data, those strips put out 88 lumens. That's with SIX LEDs. The LEDs I'm using are 145 lumens EACH. That's 10X the power of those LEDs. You can buy a 145 lumen Rebel Star for $7 each.

For drivers, try here: Luxeon LEDs - LuxDrive Drivers

You match the driver to the LEDs you are using, by operating CURRENT. Various input voltages and options are available.

BTW, these things MUST be mounted on a heat sink. I use 1x1 sinks I buy on ebay for $1 each.

The problem I have is that the mounted LEDs are available only in a "cool white", 6500K, which has a LOT of blue in it. That's why I bought some 4100K LEDs and I'm having them mounted in Thailand (ugh!). My soldering skills just aren't THAT good. The LEDs are the size of those mini chicklets.

All being said, this project is, so far, an absolutely ASTOUNDING success. Mamma LOVES the lighting. I'll see if I can't take some photos at the boat this weekend.

P.S. Yup. I'm a newbie around here...

[Whimsical]

Originally Posted by Alan Wheeler

all lighting circuits should be in parrellel. So turning on or off a light or LED should not alter current. .

Sorry Al I don't see the relevance of that.
Suppose you have 2 leds in seperate fixtures both driven by a common current regulator, which is what Deepfrz was suggesting I think, and each requiring a current of 50 mA. The common reg has to be set for 100 Ma. If you turn off one fitting the reg will be trying to stuff 100 mA into the one that is on.
It is quite possible to use a voltage reg with a led to set the current but most leds have a -ve thermal coefficient which will lead to self destruction so the current needs to be set a bit low and the reg needs to be stable, this is why I suggested a small current limiting resistor.

Individual switch mode drivers will give the best result if efficiency is the goal
LEDsales. LEDs, nixies and other cool stuff. - Switchmode and other drivers

Mike

[Whimsical]

Originally Posted by bstreep

I'm having them make me a star with 2 white LEDs and 1 red, to replace my light over my chart table.

How many are you getting made. If you want to unload some let me know.
The built in night light is just the thing I am looking for and am too lazy to assemble myself.

Mike

[bstreep]

Mike,

I'm just having 8 made. Mamma wants to see if she likes these warmer LEDs better than the 6500Ks. I have 6 of the 4100Ks, 1 with 2 4100Ks and a red LED, and one with a blue (for my 215 gallon reef tank, but that's a WHOLE 'nother story - I have a living reef in my house!). Once I evaluate these (read: Mamma decides what she likes best), I'll put together an order for about 75 LEDs, and 15 drivers.

[eric58]

bebi-electronics.com. a small company in Fiji makes leds in a variety of configurations that will work in your existing light fixtures, they ship quickly. worked for me.

[bstreep]

Eric,

You are kidding, right? This product, with TWELVE LEDs (a reading light), puts out all of 14.8 lumens! Marine RV Off-Grid Ultrabright Waterproof LED Cabin Reading Spot Light Bulb Assembly

This is archaic, by LED standards. 1.2 lumens per LED.

Note, also that they sell navigation lights, that specifically, are NOT USCG approved.

[Maren]

Originally Posted by bstreep

Mark, I'm not sure, but reading the data, those strips put out 88 lumens. That's with SIX LEDs. The LEDs I'm using are 145 lumens EACH. That's 10X the power of those LEDs. You can buy a 145 lumen Rebel Star for $7 each.

I know this is not a static area and that it's pretty much pointless to say A is better than B but ... 240 lumens

From the page:

The P4 emits 240 lm at 1 A of light and features the industry’s highest luminous efficacy (100 lm/W @ 350 mA at the maximum) with only a single die, making it a brighter and more cost-effective light source compared to conventional 70 lm/W fluorescent and 15 lm/W incandescent lighting options.

No idea on the cost though.

[witzgall]

How does your $60 home made unit compare to a ~$40 sensi-bulb?

SensiBulb LED Light - Fourwinds Enterprises

Chris

Originally Posted by bstreep

Mark, I'm not sure, but reading the data, those strips put out 88 lumens. That's with SIX LEDs. The LEDs I'm using are 145 lumens EACH. That's 10X the power of those LEDs. You can buy a 145 lumen Rebel Star for $7 each.

For drivers, try here: Luxeon LEDs - LuxDrive Drivers

You match the driver to the LEDs you are using, by operating CURRENT. Various input voltages and options are available.

BTW, these things MUST be mounted on a heat sink. I use 1x1 sinks I buy on ebay for $1 each.

The problem I have is that the mounted LEDs are available only in a "cool white", 6500K, which has a LOT of blue in it. That's why I bought some 4100K LEDs and I'm having them mounted in Thailand (ugh!). My soldering skills just aren't THAT good. The LEDs are the size of those mini chicklets.

All being said, this project is, so far, an absolutely ASTOUNDING success. Mamma LOVES the lighting. I'll see if I can't take some photos at the boat this weekend.

P.S. Yup. I'm a newbie around here...

[GMac]

Originally Posted by senormechanico

GMac,

Yes you are saving significant amps.

Steve B.

I am happy again All this electrical stuff can be bloody confusing.

I swapped my old fluros, some doubles, for some made in china but tidy lights. 21 LEDs per unit and give plenty of light but not overpowering. The 2 on the cockpit bulkhead can be switched red (7 LEDs) or white (14). So nice having night vision back while still having enough to read a chart surprisingly well. Only NZ$30 each odd, not bad I thought.

All I have to do now is swap out my 25W masthead Nav light and I reckon I can go for many days without having to put any charge back in, stereo excepted, the power sucker.

Can't change Nav light just yet as the racing rules require a '25W' light and don't allow an 'equivalent'. Damn.

[eric58]

thanks for the updates, I didn't realize how 'archaic' my leds are.

[Alan Wheeler]

Suppose you have 2 leds in seperate fixtures both driven by a common current regulator, which is what Deepfrz was suggesting I think,

Sorry, I am on a different page.
I was thinking of each light having it's on reg. Which is normally how the shop bought ones come and why they tend to be so expensive.
If you are going to run a bunch of independently switched LED lights, you really need a Constant Current regulator. This maintains a current of say the 50mA you used as a figure, no matter how the load changes.

[Paul Elliott]

Originally Posted by Alan Wheeler

Sorry, I am on a different page.
I was thinking of each light having it's on reg. Which is normally how the shop bought ones come and why they tend to be so expensive.
If you are going to run a bunch of independently switched LED lights, you really need a Constant Current regulator. This maintains a current of say the 50mA you used as a figure, no matter how the load changes.

Alan,

Are you describing a series connection of a current regulator and multiple LED light fixtures (like some Christmas Tree lights are wired)? And then you would have each light fixture's switch be wired across the light and be used to bypass (short out) a light when you want it turned off?

This would work for a small number of lights (as long as they each required the same current), but if this were my system I would much rather have individual current regulators.

If you are talking about a single fixture containing multiple LEDs, then yes, a single current regulator driving all the series-connected LEDs is the way to go. If you have some fixture with a dozen LEDs (example: some of these "strip" lights), then you will have to divide the led string into several paralleled strings because there would not be enough Voltage to drive the full string/regulator (in a 12V system, anyway).

[knottybuoyz]

I've recently bought some LED replacement lamps & nav lights from this e-Bay supplier.

eBay Canada Seller: jagtradingonline: Lamps, Lighting, Ceiling Fans, Televisions on eBay.ca at low prices

Haven't got them yet but his prices seemed reasonable. He's located in Australia. We'll see what they look like once they get here.