LED Reading light November 10, 2011, 05:27:11 pm Yahoo Message Number: 126530I have replaced the fluorescent tubes and the incandescent bulbs with LED, and I have been searching for surface mounted spot LED's, prefer flex but would consider adjustable. I would like to mount them at the rear, over the couches on my 24ft TK, directing for reading. Anyone have a source? Wayne[Non-text portions of this message have been removed]
Re: LED Reading light Reply #1 – November 10, 2011, 06:38:17 pm Yahoo Message Number: 126532Check www.ikea.com for lighting options they may have something that would meet your needs.Donna of the Lazy Daizy 1997 26.5' RB of Vaughn, WA
Re: LED Reading light Reply #2 – November 11, 2011, 06:32:39 am Yahoo Message Number: 126537"I have been searching for surface mounted spot LED's, prefer flex but would consider adjustable." IKEA's $10 "Jansjö" LED light comes with a weighted base supporting a two-foot gooseneck, but by omitting the base, it can be mounted upside down under a cabinet. I use one mounted this way as a computer keyboard light. Only drawback is that it requires 120 VAC rather than 12V.Andy Baird http://www.andybaird.com/travels/
Re: LED Reading light Reply #3 – November 11, 2011, 08:09:23 am Yahoo Message Number: 126540Wayne, I did such a installation with two bullet-type reading lamps I got at Camping World. One I installed as-is, the other I converted to a flexible goose-neck lamp.
Re: LED Reading light Reply #4 – November 11, 2011, 09:17:28 am Yahoo Message Number: 126541QuoteI have replaced the fluorescent tubes and the incandescent bulbs with LED, and I have been searching for surface mounted spot LED's, � prefer flex �but would consider adjustable. I �would like to mount them �at the rear, over the couches on my 24ft TK, directing� for reading. �Anyone have a source? �Wayne Finding a fixture that uses standard bayonet (15s socket) bulbs will give you a lot more flexibility in aesthetics, and bayonet-mount spotlight LEDs for reading are readily available with lots of choice. If you find a fixture designed for 1383 bulbs, such as older LD models used, this is a nice replacement bulb with a very effective beam character for reading: http://led4rv.com/index.php?main_page=product_info&cPath=6&products_id=250Just one caveat - the first two I ordered actually were mislabeled, as it turns out, and had a cool-white light. I decided I liked the light for reading. The two I just received have the warm-white light that is fine for reading and also a pleasant color for general illumination.Steve
Re: LED Reading light Reply #5 – November 11, 2011, 11:50:05 am Yahoo Message Number: 126544Quote I have replaced the fluorescent tubes and the incandescent bulbs with LED, and I have been searching for surface mounted spot LED's, prefer flex but would consider adjustable. I would like to mount them at the rear, over the couches on my 24ft TK, directing for reading. Anyone have a source? Wayne Check out www dot alpenglowlights dot com. We have an Alpenglow flourescent over our dinette and two led reading lamps at the head of each sofa aft in our mb. We discovered these lights years ago when we were restoring our Alberg 35 sailboat and are completely convinced there is no finer 12v lighting anywhere. Pricey but we think completely worth it. Carol and Linda '91 MB, '03 Wrangler
Re: LED Reading light Reply #6 – November 12, 2011, 09:17:46 am Yahoo Message Number: 126554Andy said: IKEA's $10 "Jansj'" LED light comes with a weighted base supporting a two-foot gooseneck, but by omitting the base, it can be mounted upside down under a cabinet. I use one mounted this way as a computer keyboard light. Only drawback is that it requires 120 VAC rather than 12V.' But, if you look at the wall wart, I think it says the output is 3.7 volts DC. That means an industrious person could remove the wall wart and then hook up several of the lights in series. Four time 3.7 is 14.8, so that string can be hooked to 12 volts with no problem - - though the LEDs would be slightly dimmer. Alternately, one could get fancy and install a DC to DC converter, but I wouldn't bother.bumper[Non-text portions of this message have been removed]
Re: LED Reading light Reply #7 – November 12, 2011, 10:43:35 am Yahoo Message Number: 126557QuoteBut, if you look at the wall wart, I think it says the output is 3.7 volts DC. That means an industrious person could remove the wall wart and then hook up several of the lights in series. Four time 3.7 is 14.8, so that string can be hooked to 12 volts with no problem - - though the LEDs would be slightly dimmer. Alternately, one could get fancy and install a DC to DC converter, but I wouldn't bother. If you just need to produce a lower DC voltage at low current, this is really easy to do with inexpensive parts. An LM317 regulator with a couple of capacitors and resistors should just be a few bucks. I know not everyone has the background to try this, but I know there are a few folks capable of trying it.Art
Re: LED Reading light Reply #8 – November 12, 2011, 11:46:28 am Yahoo Message Number: 126559QuoteIf you just need to produce a lower DC voltage at low current, this is really easy to do with inexpensive parts. An LM317 regulator with a couple of capacitors and resistors should just be a few bucks. I know not everyone has the background to try this, but I know there are a few folks capable of trying it. One thing to be aware of is regardless of what is printed on the 'wall-wart', these unregulated LED chips require a specific drive current. Designing for an output of 3.7V could actually either burn out the light or at least cause brighter operation and a short life span. The 317 regulator CAN be configured to supply a specific drive current, if you can determine what it should be. However, it is a linear regulator, and will not provide the high efficiency of a PWM circuit, which is what most LED drivers are these days. For example, if the chip requires 250mA and that corresponds to 3.2V, the power consumption is 800mW. Using the LM317 as the current source, the power consumed will be 250mA @ 12V, or about 3W. This means you are dissipating 2.2W in the regulator.Steve
Re: LED Reading light Reply #9 – November 12, 2011, 12:32:33 pm Yahoo Message Number: 126561On 11/12/2011 8:37 AM, older_fossil wrote: QuoteIf you just need to produce a lower DC voltage at low current, this is really easy to do with inexpensive parts. An LM317 regulator with a couple of capacitors and resistors should just be a few bucks. I know not everyone has the background to try this, but I know there are a few folks capable of trying it. My "whole house" inverter is on all the time, so I'll just plug the lamp into AC when I get one. If you don't want to run a 1000+ watt inverter to run a light (mine uses 500 ma even when not powering anything), a small 30 watt to 100 watt inverter would power many AC LED lamps with a much smaller current drain penalty.Eric
Re: LED Reading light Reply #10 – November 12, 2011, 01:59:15 pm Yahoo Message Number: 126565"these unregulated LED chips require a specific drive current. Designing for an output of 3.7V could actually either burn out the light" Right. Any LED can be made to go "BANG" (literally) at its rated input voltage if you feed it unregulated current. The old, crude way of getting around this was to use a current-limiting resistor, but this is tremendously wasteful--really only suitable for low-power LEDs. A linear regulator such as the LM317 can do the job, but as Steve points out, this is also wasteful. And tinkering up a 12V-to-3.7V PWM converter is beyond my skills. I've looked around online, but haven't been able to find anything suitable. If anybody comes up with anything that's available off the shelf--or even plans!--I'd love to hear about it. Meanwhile, I do as Eric does and run the Jansjö lights from my whole-house inverter (or from shore power), which is usually on in order to power the iMac.Andy Baird http://www.andybaird.com/travels/
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