Cheap inexpensive LED upgrade

[kaz911]

Can you explain #3

Every LED light has a power supply/regulator - some don't and rely purely on resistors (don't even try those) - Power supplies spec'ed/designed by western companies - built in china are generally much better.

I'm not an EE but I understand OHM's law quite well and the constant voltage drop across a diode and in this case an LED. I would need something better than (don't even try these)

Thanks,

-Mike

Resistor based power dividers are fine for PRE regulated power where you know that you get 13.6 volt all the time. They are not very good for automotive where power fluctuates between 11.5 - > 14.5 volt - often with high spikes from engine turn on/turn off.

Just do the calculation with ohms law... First do it 11.5v 20ma - then on 14.5v 20ma... So pure resistive drive of LEDs are not the smartest for automotive. You would need (homebrew) somewhere from 500 - 750 ohm to drive a single LED plus you need 0.5 watt resistors (you design with 40% safety margin) - Even in SMD 0.5 watt is a relatively large sized resistor (In SMD they are usually around 2010 size)

But then there is little or no protection. My figures above are far below what you will really see in Automotive electrics. Normally we calculate with power surges from around 6 volt to spikes of 36-80 volt or more when I design for automotive use. The moment your alternator stops pumping power (when you switch the engine off) - you might see spikes of close to 90 volt on the supply line. That is deadly for only resistor based circuits.

For Automotive use (alternator connected) the only right way to power high brightness LED's is with a constant current source power supply. Nothing else is safe. Alternative is to put a 13.6 volt regulated power supply on your cabin lights switch/breaker. Many companies do them for marine use - like Mastervolt for example.

 

[northshore]

...


But then there is little or no protection. My figures above are far below what you will really see in Automotive electrics. Normally we calculate with power surges from around 6 volt to spikes of 36-80 volt or more when I design for automotive use. The moment your alternator stops pumping power (when you switch the engine off) - you might see spikes of close to 90 volt on the supply line. That is deadly for only resistor based circuits.....

Thats the argument right there - transients!

Thanks,

-Mike

 

[Bama Boater]

Great stuff on LED(s) here. Looks like there's a lot more to it than simply replacing a bulb.

 

[Bama Boater]

"We now see a flood of cheap Chinese and Singaporean lights in the market. Many of you may have already heard about the short lifespan products, boat fires, exploding bulbs, and radio interference. Educate yourself and then you can make a good choice when selecting products." - Marine Beam

I like this Idiots Guide: http://ep.yimg.com/ty/cdn/yhst-54258538930337/IdiotsGuide.pdf

 

[kaz911]

Thats the argument right there - transients!

Thanks,

-Mike

I was trying to keep it low key with volt and ampere and here you bring in transients... But yes - among other spike sources. Even your bilge pump can create a big kick in the backside when it starts and stops (or sump pump when someone use the shower)

 

[ZZ13]

All this engineering analysis is pretty cool and informative. Thanks Kaz.

I can tell you when I bought cheapo LEDs they were so hot I got scared. I got rid of them. I use only the more expensive stuff that I know is cool to the touch, from superbrightleds. You get what you pay for.

 

[kaz911]

All this engineering analysis is pretty cool and informative. Thanks Kaz.

I can tell you when I bought cheapo LEDs they were so hot I got scared. I got rid of them. I use only the more expensive stuff that I know is cool to the touch, from superbrightleds. You get what you pay for.

Thanks - I'm an newbie compared with the smart guys I took a pause from electronics for 20 years and have just recently (for 2 years) started getting back in the game. More info to come as it is as you [might have] guessed.. boat related...

Anyway - the MarineBeam guy knows what he is talking about. DC Buck/Boost is the way to go - and most of those in integrated chip form - the regulator without any other support component - costs around $1-$2 in quantities of 1000 from the good guys. China Export devices can be found for $0.3 - but guess how long they last... You can build a Buck/Boost converter with cheaper components but then it probably wont fit into a light-bulb as the sizes are larger.

So if you only pay $2-$4 - there is not much room for quality components in that bulb....

 

[northshore]

I was trying to keep it low key with volt and ampere and here you bring in transients... But yes - among other spike sources. Even your bilge pump can create a big kick in the backside when it starts and stops (or sump pump when someone use the shower)

Just for laughs, I'd like to put a scope across the 12 VDC when my 25 year old refrigerator cycles!
Again Kaz - great answers and info!

BTW:I also wandered away from the EE path years ago and started writing firmware. I guess I didn't have enough grief in my life :grin:

-Mike

 

[kaz911]

Just for laughs, I'd like to put a scope across the 12 VDC when my 25 year old refrigerator cycles!
Again Kaz - great answers and info!

BTW:I also wandered away from the EE path years ago and started writing firmware. I guess I didn't have enough grief in my life :grin:

-Mike

Firmware - hmm I thought that was EE work as well *G* my TI Tiva and MPS430 seem to tell me that.

Anyway if you are bored you can help write an open source NMEA 2000 protocol stack for my open source NMEA 2000 developer board (which fits on Tiva/MPS430 development boards. I'm almost done with the prototype for the board and can parse incoming NMEA 2000. Estimated first run around dec/january.

But that is not my "big project"

 

[northshore]

Firmware - hmm I thought that was EE work as well *G* my TI Tiva and MPS430 seem to tell me that.

Anyway if you are bored you can help write an open source NMEA 2000 protocol stack for my open source NMEA 2000 developer board (which fits on Tiva/MPS430 development boards. I'm almost done with the prototype for the board and can parse incoming NMEA 2000. Estimated first run around dec/january.

But that is not my "big project"

I do believe we have 'eaten similar dog food' :grin: When not doing the managerial goo, I'm currently working with the TI C2000 Piccolo (28xxx) along with some dsPIC micros.

I'm still doing side work for my old company so time is tight but might be able to help with the NEMA stack later in the year.

-Mike

 

[kaz911]

I do believe we have 'eaten similar dog food' :grin: When not doing the managerial goo, I'm currently working with the TI C2000 Piccolo (28xxx) along with some dsPIC micros.

I'm still doing side work for my old company so time is tight but might be able to help with the NEMA stack later in the year.

-Mike

Haha I did the goo for 20 years and by luck/accident landed doing internet from '94 - and only did software "for fun" Python/Erlang and some C#. Before that I was lucky to work electronics as in developing ISA/MCA/EISA bus cards and software for it in Turbo-C/Turbo Pascal. I was lucky enough to bump into the "creator" of Turbo Pascal before it was Turbo Pascal (Poly Pascal) so I got a real early start on that long before I started my higher education.

Now I have a low maintenance Internet business that kind of sponsors my "semi-retirement" on a monthly basis - and gives me time to do Electronics.

 

[Half Fast]

Love the discussion on this. My only update is that we are approaching September and besides the bad bulb that crapped out within minutes the rest have gone strong all season, operating at a fraction of the temperature of the bulbs they replaced (talk about lighting paper on fire) while running on battery, running alternator, and shore power charger conditions.

Clearly peace of mind carries a $ value and my approach was not meant to be for everyone. Cheers!

 

[stwischu]

Agree half fast. I followed your lead and replaced all my cabin bulbs. I work in aerospace defense life support and appreciate the value of 99.9% reliability in electronic components for such applications. However for my boat I will try these cheap ones out. I don't expect them to explode but if they die out it will be a lesson learned.

 

[Bama Boater]

Love the discussion on this. My only update is that we are approaching September and besides the bad bulb that crapped out within minutes the rest have gone strong all season, operating at a fraction of the temperature of the bulbs they replaced (talk about lighting paper on fire) while running on battery, running alternator, and shore power charger conditions.

Clearly peace of mind carries a $ value and my approach was not meant to be for everyone. Cheers!

That's great. This discussion has been an education for me.

 

[garmett]

Chiming in on the LED thread,
I would like to replace all of the cockpit lights with LED's.
If anyone has done this, and are happy with the results on a 04-06,... 320 or similar type,.....
I would appreciate knowing where to purchase, and part numbers!
Many Thanks!!

 

[strange weather]

marinebeam.com--you can match up with the pictures-cockpit lights are 42m festoon=match for that bulb 1-11/16" festoon LEDBulb - 6 led Power Cluster-Blue or white -I went with blue-awesome-should be 5 on your boat-didn't change the transom light-good luck

 

[gerryb]

Thought I'd add my .02 to this thread. I've purchased almost 50 led light bulbs for two different boats, and another 50+ for various residential projects. This represents an obviously significant investment in money.. and time.. and, along the way, I've picked-up quite a bit of first hand experience with this topic.

For the boats, I've purchased different brands including the ones from amazon, the cheap ones from china and the ones sold at Marinebeam. Bottomline... if you value light quality AT ALL, go with the marinebeam. Yes, they cost approx. 5-10x more than other cheapo brands but the light quality is 100x better as is the build quality. They look and feel light halogens and function marvelously. I've kept some of the cheap china bulbs on the boat where I really don't care about the quality of the light, but in the salon and cabins, marinebeam's lights are well worth the money. Call them as they sometimes have discount promo codes available. (Perhaps someone should check about setting-up a discount code for members of this board as that is something they have done in the past for other groups.)

 

[CPT2012]

+1 for Marinebeam, recently replaced all bulbs with Leds in my 58. Good quality at a reasonable price. No more heat from halogens.
Went through some chinese bulbs from Amazon before, but not reliable.
Make sure you match the right voltage, my boat lights are 24v but it goes up to 28v while charging, the bulbs must be able to handle that load (most of marinebeam are 10-30v).

 

[EKM]

I bought 12 of the 10watts....light quality is good but failure rate is high. 3 of the 12 have failed after 3 weeks of weekend use. The 20w seem to hold up better but no failures but don't fit in my flush fixtures.

 

[Waterguy]

So, a few years later, how have your LEDs held up?