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12-11-2013, 14:43
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#76
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Registered User
Join Date: May 2011
Location: Lake Ont
Posts: 8,570
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Re: Problems with Dr. LED Lights
Quote:
Originally Posted by Rick
Addressing Cpt Pat and Lake-Effect:
Having designed alternator voltage regulators, battery monitors, inverters, and various industrial electronics (including 40 Watt LED panels for photography) I can assure you that the actual design spec for nominal "12V" marine, RV and automotive applications require a minimum tolerance of 10 to 18 V range. The lower limit is not a "dead" battery value it is the value UNDER LOAD that can easily be 10V or less even though the battery at "rest" may be above 10V. (as a note, lead-acid batteries, which include AGM and gel-cell can very well survive a 10V standing voltage depending upon many factors). Sophisticated charging systems can approach 16 V when using the Amp-hour Law charging algorithm and, therefore, lights must tolerate that value. I have routinely used that algorithm on my own boat with AGM and Gel-cell batteries with long life (15 years and more) with many deep discharges and rapid recharging under high currents).
Regardless, even with a constant dc input to an LED driver a switch-mode regulator is necessary to convert that voltage to a constant-current driver to guarantee meeting the LED manufacturer's spec for light output and lifetime. Yes, it is possible to do that with a linear regulator yet, again, the losses are intolerable if one is minimizing any heat-dissipation requirement which would often meet or exceed the cost of a good switch-mode design.
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Hi Rick,
I appreciate the clarification. Re linear regulation (which can be constant-current) or simple dropping resistors, I was mainly referring to what's possible, especially for the DIYer, and not to what should be taken as a commercial standard.
For our little boat, simple DIY LED units have sufficed, and still provide significant energy savings, and no RF emissions problems. I'm waiting for the commercial units to get 'debugged' in the real world (sailors -thanks for being guinea pigs ), and then to come down in price.
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12-11-2013, 15:30
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#77
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Nearly an old salt
Join Date: Jun 2009
Location: Lefkas Marina ,Greece
Boat: Bavaria 36
Posts: 22,801
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Quote:
Originally Posted by Dockhead
A good way to be sure that an LED G4 unit or fixture is buck regulated is to buy only ones rated for 10-30 volts.
I don't have any choice anyway since I'm on 24v power.
My boat is one giant test bed for different LED units. I've bought from at least a dozen suppliers.
My remaining Suoerbrights have all burned up. Never buy from them again.
The very expensive Sensibulbs, top rated some years ago, continue to disappoint, dim, and bulky. One of them has lost its light output progressively to the point that it is no more than a night light.
The others (from Imtra, Dr LED, Marinebeam, Boatlamps, UltraLEDs, and others I can't remember) are still all going strong.
I have discovered inexpensive downlighting fixtures which replace the horrendously crappy Cantapuli G4 halogen fixtures which were part of the original build. The take MR16 format units which are available in much greater light output than G4. So I've been putting these in in places where I need good light (over the galley stove, over the salon table, etc).
My favorite supplier has become Bedazzled.co.uk, although lately I've even bought a few from Farnell. I think these LED suppliers are generally just a guy who has ordered a few crates of LED units from China and ships them from his garage on a 700% markup. But I have been pleased with Bedazzled - quality stuff, pricing not as rapacious as others, very good advice over the telephone. Their stuff is all fused, buck regulated, and RFI suppressed, and has worked flawlessly, and giving more pleasant quality light than others.
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I've used bedazzled LEDs too. But I agree with u I think there are all china.
Dave
__________________
Interested in smart boat technology, networking and all things tech
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08-12-2013, 00:17
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#78
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Registered User
Join Date: Aug 2008
Boat: San Juan 7.7 26 feet
Posts: 5
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Re: Problems with Dr. LED Lights
Completely refitting STRIDER with Dr LEDs - everywhere - 5 interior, 3 running, 1 steaming, 1 handheld spot. Happy to report zero problems with repeated testing since installation October 2013. Especially like the brilliance of the Coast Guard Approved 2NM running lights plus the pleasant warm wavelength of the interior fixtures. Their output resembles the original incandescents only better with selectable high/low settings. Battery monitor shows very little draw as promised. Looks like I got what I paid for ... very pleased so far.
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08-12-2013, 04:59
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#79
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Registered User
Join Date: Oct 2011
Boat: Valiant 42
Posts: 6,008
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Quote:
Originally Posted by Hugh Stewart
Completely refitting STRIDER with Dr LEDs - everywhere - 5 interior, 3 running, 1 steaming, 1 handheld spot. Happy to report zero problems with repeated testing since installation October 2013. Especially like the brilliance of the Coast Guard Approved 2NM running lights plus the pleasant warm wavelength of the interior fixtures. Their output resembles the original incandescents only better with selectable high/low settings. Battery monitor shows very little draw as promised. Looks like I got what I paid for ... very pleased so far.
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Have you checked whether your radios are working as well as before with all the lights on?
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08-12-2013, 14:04
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#80
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Registered User
Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 7,265
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Re: Problems with Dr. LED Lights
Re: voltage swings when charging, this is just one more reason to switch to Lithium Phosphate batteries.
The voltage swing is a LOT less.
We routinely see no less than 12.8 and no more than 13.8 volts.
__________________
'You only live once, but if you do it right, once is enough.
Mae West
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27-06-2015, 14:28
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#81
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Registered User
Join Date: Mar 2012
Location: Ventura, CA
Boat: Dynamique 62
Posts: 5
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Re: Problems with Dr. LED Lights
Here's a copy of the letter I just wrote to customerservice@drled.com :
"I’m having a heck of a time putting TWO working Kevin X4 units up on my spreaders at the same time. I’ve been up and down now three times, I’ve been checking the power cables all along, there’s good voltage up there. This last time was like all the others, namely the light tests out okay downstairs, and then I get it up on the spreaders and test it again (fine) and then by the time I’ve got BOTH lights on the circuit the one light has flickered out to two cells in the X4 array, and then the entire light stops working - which is new in this last effort. The time before, the light just kept working with two cells. But now I’ve just got a dead light, and this is the third one in a row. I can’t imagine what I’m doing wrong. Any advice?
And actually, while I've been writing this, the light that was previously working has dropped two of its four LEDs, so I've got a full-dead and half-dead set of brand new spreader lights. What the hell is going on?"
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28-06-2015, 06:25
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#82
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Registered User
Join Date: Jan 2011
Location: Caribbean live aboard
Boat: Camper & Nicholson58 Ketch - ROXY Traverse City, Michigan No.668283
Posts: 6,641
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Re: Problems with Dr. LED Lights
Quote:
Originally Posted by slowshoes
I'm also in the market for a led replacement bulbs that are bright and have a warm light to them, not the cooler blue type light that many seem to have. Any suggestions would be appreciated.
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We replaced our Nav, Cabin, Deck lights with replacement bulbs form Marine Beam - No problems with over 60 of their PWM current regulated bulbs. They do not take a lightning hit so well though. Marine LED Lights; Cabin, Navigation and Deck | Marinebeam Go to "find your LED bulb" to find the correct bulb. We have the red/green/white emitter replacement for the Aqua Signal Tri-color replacement Tri-Color LED Replacement Bulb This is very bright & very durable. I attached a picture of our Tri-Color with this bulb. I also added dividers to make sure the cut-off angles would be sharp. The peel & stick aluminum also gets more light out. This thing is fiercely bright and can be seen easily well beyond 2 miles. We use this at sea and the deck level Nav lights in busy congested arias (Signal Mate)
We also bought Signal mate bow/stern Nav lights. The first set was their model -0- at the Chicago boat show special. They too filled with water before we ever left the dock. Interestingly, the fully potted guts continued to work anyway. Signal Mate happily and quickly replaced these with their newer model. (before & after photos) I made SS brackets using Edson ball mounts. Signal Mate is not cheap but they have been a good vendor & the lights are far brighter than ordinary 2-mile. The LEDs for the bow are red & green emitters so no colored lens is used, this no color spectrum lost in filtering and all power is used to make light.
All LED bulbs for marine application should be PWM current regulated. If you don't see this in the description, you may be getting resistor regulated bulbs. These are usually rated only 12 VDC and are generally much lower cost. The PWM bulbs are often rated 9 to 32 or some other all inclusive range. These will operate at a constant power consumption and output over a wide range of input. They will therefore work on drained batteries and under the higher charging voltage without damage. Their Lumens/Watt consumed will be higher than any other type. Good Tech discussion here. LED Technical Information Page
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28-06-2015, 06:53
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#83
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Registered User
Join Date: Oct 2011
Boat: Valiant 42
Posts: 6,008
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Problems with Dr. LED Lights
Quote:
Originally Posted by Norsely
What the hell is going on?"
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I can make a "guess" what is going on. LED lights are often driven with very high current pulses for short times. The average current is low but the peak current is high. The long cable up the mast may not be able to keep the voltage high enough during the peak load and the "smart" drive circuitry shuts down due to low voltage. It would take specialized equipment to test for this theory.
There might be no good solution if the theory is right. A large capacitor at the spreaders might help but would not be easy to install. Another thing that might help is larger wires that are twisted together all the way from the breaker to the fixture. But again, this is very hard to do.
Did you measure the voltage at the fixture when the lights are switched on?
Let us know what Dr.LED say about it.
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28-06-2015, 07:32
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#84
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Registered User
Join Date: Jan 2011
Location: Caribbean live aboard
Boat: Camper & Nicholson58 Ketch - ROXY Traverse City, Michigan No.668283
Posts: 6,641
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Re: Problems with Dr. LED Lights
Quote:
Originally Posted by transmitterdan
I can make a "guess" what is going on. LED lights are often driven with very high current pulses for short times. The average current is low but the peak current is high. The long cable up the mast may not be able to keep the voltage high enough during the peak load and the "smart" drive circuitry shuts down due to low voltage. It would take specialized equipment to test for this theory.
There might be no good solution if the theory is right. A large capacitor at the spreaders might help but would not be easy to install. Another thing that might help is larger wires that are twisted together all the way from the breaker to the fixture. But again, this is very hard to do.
Did you measure the voltage at the fixture when the lights are switched on?
Let us know what Dr.LED say about it.
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Dan, others, Please read my previous post. Our mast is 80 feet. If you buy good quality marine PWM LEDs there is no problem. The current draw for these things is so low that any existing wiring designed to standards and for powering incandescent bulbs is oversized. I urge reading of the tech link to get a handle on PWM and other (inferior) current regulating techniques. Note that nearly all NAPA and other bulbs intended for automotive use are the worst LEDs you can buy. Many of these are also still sold through marine distributors as well. This is one case where lowest cost shopping is not your best plan.
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28-06-2015, 11:16
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#85
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Registered User
Join Date: Oct 2011
Boat: Valiant 42
Posts: 6,008
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Re: Problems with Dr. LED Lights
PWM is too generic in my opinion. There is "good" PWM and "bad" PWM. What is good or bad depends on the goals and application. LEDs are at their most efficient when over driven. But if overdriven 100% of the time they would be too bright and die from overheating. So PWM can be used to give the LED short pulses of high current to achieve the desired brightness and high efficiency. This type of drive circuit needs ready access to a high current source such as a battery. Without it the voltage drops and the circuit can't function. Long wires tend to cause this effect. Radio interference is usually a byproduct too.
Anther type of PWM tries to convert the 12V to a regulated voltage (usually lower) and this lower voltage creates a constant current in the LED. Some vendors say "constant current" in their literature. Unfortunately, a resistor in series with an LED can also be constant current so that isn't a good way to differentiate.
I agree that Marinebeam have a boater friendly constant current PWM design. But there are other PWM designs that are not friendly to boats (or radios). And these unfriendly designs can have higher efficiency and cost less to manufacture.
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29-06-2015, 12:41
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#86
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Registered User
Join Date: May 2011
Location: Lake Ont
Posts: 8,570
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Re: Problems with Dr. LED Lights
For all the bright LEDs I've seen, the peak current has been ~ 300 mA or or less (per LED device or series string), and the better PWM controllers will have an onboard capacitor to provide current peaks. So the typical mast lighting wiring, which supported incandescent bulbs, should be more than sufficient for any LED replacement or fixture.
I don't think inadequate wiring is the source of Norsely's issues. Sounds like just bad fixtures or LED assemblies to me.
I have found from trial and error that LED lighting assemblies need protection from static (eg while handling and raising mast) which can easily exceed the reverse 40v that would destroy any LED, and from electric fields (eg nearby lightning). My first attempt at DIY nav lights all ceased working in about 6 months or less. My second attempt incorporated reversed diodes and local capacitors to eat up transient and reverse voltages, and they have survived 3 seasons now. I wonder if commercial LED replacement bulbs have all been similarly protected.
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29-06-2015, 16:47
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#87
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Registered User
Join Date: Oct 2011
Boat: Valiant 42
Posts: 6,008
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Re: Problems with Dr. LED Lights
All the Marinebeam LEDs I have looked at are polarity insensitive.
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29-06-2015, 19:23
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#88
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Registered User
Join Date: Jan 2011
Location: Caribbean live aboard
Boat: Camper & Nicholson58 Ketch - ROXY Traverse City, Michigan No.668283
Posts: 6,641
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Re: Problems with Dr. LED Lights
Quote:
Originally Posted by transmitterdan
All the Marinebeam LEDs I have looked at are polarity insensitive.
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They have diode rectification on the circuit boars of most (cabin) light replacements. My deck lights form Marine Beam are 800 lumens at 10 watts consumed. They will operate from 9 volts to nearly 90. I was told that the PWM circuit in these can even handle 110 AC (not recommended). We lost three of six in a direct lightning hit last July after four years aloft. Marine Beam replaced the outright. These replaced 4-1/2" sealed beams that were 300 lumens and 50 watts. The peak instantaneous power demand of any of these is less than the IC bulbs they replaced. You buy PWM from trusted sources. I like the results We have had with both Marine Beam and Imtra replacement bulbs.
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29-06-2015, 22:21
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#89
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Registered User
Join Date: Dec 2010
Location: Pacific Northwest
Boat: Boatless in Seattle. Ex- Alberg 30, 30’ Gillnetter, 63’ Wm. Hand Ketch, 36’ Lapwor
Posts: 296
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Re: Problems with Dr. LED Lights
I have no idea what would happen with LED's, but we had a similar situation last year with old style incandescent spreader lights. When we pulled the mast and reinstalled, one of the wiring pairs accidentally got reversed and caused a short at a terminal we have mounted amidships. We had 12volt readings at the panel, but no spreader lights. Eventually traced the wiring and found the short below the mast step where the mast wiring harness connects to the boats electrical system. Dumb mistake, but an innocuous location, so it took a while to figure out.
Just suggesting check your wiring harness all along the route up to the mast. Maybe there is some hidden damage somewhere causing your lights to malfunction.
Sent from my iPad using Cruisers Sailing Forum
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19-08-2019, 13:03
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#90
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Registered User
Join Date: Nov 2018
Posts: 3
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Re: Problems with Dr. LED Lights
These posts about Dr. LED from 2010 do not promising. Now its 9 years later and I see they are still in business. I am considering purchasing some bulbs from them. Can anyone give me current insight/opinions on Dr. LED and their bulbs????
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