Cheap LEDs: amp usage? quality?

[JBP]

You can get festoon led bulbs on amazon for about $1-2 to replace the bulbs in your existing fixtures. The cool white are too cold for my taste, I'd go with the warm color. "White" LEDs are actually a uv led with a phosphor coating. (As opposed to RGB leds which combine 3 colors to simulate white) The quality of the color varies a lot among brands. The color rendering index CRI gives you an idea of how well it simulates true white light (CRI 100), but cheap ones won't list the CRI.

[Rorzech]

I found some really cool 15 m long led strips 24 W so plenty bright . Remote can make them go solid red or green or white or blue. For about 8 $ they're a steal. I like the idea of red for night light and white for when needed. I'm going to grab a few more today. You might be able to shorten them I'm not sure. I don't know if I can name the online store ,so I won't ,in fear of getting shown the door. PM me for it.

[hamburking]

Originally Posted by Tugwit

The following website offers a rule-of-thumb for energy consumption of LED lighting based on the specified light output (lumens) of the fixture: https://www.thelightbulb.co.uk/resources/lumens_watts/

Your Blazer rectangular dome light specifies 400 lumens of output; accordingly, it may be expected to consume 6 watts of power. Since watts = volts x amps, at 12 VDC the fixture should draw 6 watts/12volts = 0.5 Amps or 500 mA.

The website you referenced is about brightness...finding the equivalent LED bulb to replace the 60watt bulb we are all familiar with, for example. I understand what you have done, extrapolating power consumption from the "wattage", but the "wattage" is given as a function of brightness, not power consumption.

What is does show is that your 400 lumen led fixture is the equivalent of an old style 40watt incandescent bulb. Wow...that's a bright light on a boat. Anything over 100 lumens is going to be blindingly bright as an interior light. For comparison, these $15 red/white led fixtures (with switch) from west marine are 20 lumens. They are similar to the fixtures I installed on my boats. And I found them to be very bright...had to be mounted indirectly, or they were blinding.

So, to be fair, and to keep the math simple, a 40 lumen light is sufficient below, and using your math, the draw would be 0.05 amps.

[Sunsetrider]

Originally Posted by esarratt

Thanks! These just went on the buy list for my boat and cabin.

Ya me too - but do we have an answer to the connection question?

[skipmac]

Originally Posted by Sunsetrider

Skipmac, this is probably a dumb question, but how do you connect the strips to power? It looks like they connect to each other to make a series if desired, but then are there matching plugs to connect to the power source?

I bought these a few years ago and each 19" strip had red and black leads about 6" if I recall. I just used a crimp fitting to connect them to the power wires that fed the old lights. The new ones look like they have some kind of connector on them. I would just cut that off and crimp into the existing wiring.

For switches I went to Digikey and bought a few different switches based on where I mounted each light and the best way to switch it. The switches I added inline to the positive power wire from boat to LED.

For several places on the boat I bought the remote control/dimmer that so far has worked quite well. FYI the same remote/dimmer units I bought from superbrightleds.com I found on eBay for about half.

[CarinaPDX]

The strip (rigid or flexible) LEDs usually have a design that repeats every 2-1/2" - 4". The places for cutting (between repetitions) have solder pads on either side, so after cutting either solder leads onto the pad or push on a connector available for the purpose. Simple.

The pulsed modulation style regulators should be avoided as previously mentioned. It is quite easy to find constant current power supplies to drive LEDs, and if dimming isn't required they can be found cheaply on flea-bay. I have been buying the excellent Flexcharge regulators, which are designed for constant current output and dimming; not cheap though...

I am converting my interior lights to LEDs. I am using COB (chip-on-board) LEDs in straight strips for my overhead Alpenglow compact fluorescent lamps, and round ones for my reading lamps. COB LEDs are modules with LED chips in both series and parallel arranged on a board and covered with a yellow plastic substance that contains the phosphors for white light. There are no resistors or regulators on the boards so are ready to be driven by a constant current source. The light is more diffuse than most LED fixtures (it is difficult to see the separate LED chips). For bright LEDs it is necessary to provide heat sinking, which may be just a good thermal contact to an aluminum backing plate or a proper extruded heat sink. I will write up the designs when I finish installing them (I have the parts and have tested them to my satisfaction).

I dislike using terms like "cool white" and "warm white" as vendors have been playing fast and loose with them. The "warm white" compact fluorescent bulbs are usually a 2700ºK white, while "warm white" LEDs are often 3000ºK, 3200ºK, or even 3500ºK. The 2700ºK bulbs closely match incandescent bulbs, but since I haven't used them below for a couple of decades there is no need to stay there for consistency. I am using LEDs of around 3200ºK for my conversions, which I prefer. The 5000ºK to 6500ºK bulbs are too harsh for my taste. YMMV, but use the white temperature for clarity.

Greg

[skipmac]

Originally Posted by Sunsetrider

Ya me too - but do we have an answer to the connection question?

Sorry was out most of the day and just got to the connection thing. It is pretty straightforward but you do need to make sure you connect then with correct polarity or you get no light.

[FionaJC]

I had florescent 2d lights with a switch on each unit. I replaced them with two square led blocks bought from eBay for about £3. They were all warm white except over the nav desk when I used cool white. The heads have just a single package. So I bought 15 units. Less power consumption, no rf noise and they still work if the batteries are running low as they don't need to strike. I also fitted 2x 48w and 2 x 18w led' s for deck lights and bow head lights. Not too worried about consumption on these as I use them when motoring in tight harbours.

[waterman46]

Gradually replacing all 20 incandescent bayonet and halogen two pin base bulbs in the interior fixtures of my boat. Initially got cheaper LEDs from an online distributor in China but many of those wouldnt work at all or got flaky after a few hours. So be careful where you buy.

I need to have about 6 of these in red color but havent found any bayonet base in red yet. Tried red paint as I have used on incandescents but the paint wont stick evenly.

[waterman46]

Originally Posted by S/V Illusion

Cheap LEDs are notioriously noisy RF generators which can interfere with radio communications. Many have been taken off the market by the FCC but still widely available worldwide. LED dimmers moreso. Some people are simply unaware of the problem.

Isnt this noise issue only a real problem with LED used in 120 vAC applications? I added several 12V LED bulbs in my boat and didnt notice any more noise on my ham radio rig.

[conachair]

Originally Posted by waterman46

Isnt this noise issue only a real problem with LED used in 120 vAC applications? I added several 12V LED bulbs in my boat and didnt notice any more noise on my ham radio rig.

It can be a problem with cheap regulators but the majority of cheap LEDs just have a resistor in series so no chance of creating RF. Better regulated LED lamps have filtering built in so should be OK.

[skipmac]

Originally Posted by waterman46

I need to have about 6 of these in red color but havent found any bayonet base in red yet. Tried red paint as I have used on incandescents but the paint wont stick evenly.

Here's 5 different two pin LEDs that I believe are in red.

https://www.superbrightleds.com/sear...,Red,136,4639:

[boatpoker]

Here's how I switched over about 12 years ago to the cheapest LED's I could find at the time from Ikea. Work great, no problem whatsoever.

Sold that boat 3yrs ago and they are still working for the new owner. One of my first projects on the new boat was to do exactly the same thing with the same product.

[Sunsetrider]

Thanks for the tips, Boatpoker. Looks like a solution for avoiding the crazy cost of replacing fixtures. But no detail on the final box - LED bulbs in existing fixtures - leaves me wanting more! How does one glue the LED in? And how to choose the right LED? Any further info on this?

[SeaSon]

I used my old fixtures and installed cheap led bulbs, worked great! I found the white appeared too industrial, so changed to the off white.