Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 20-05-2014, 20:39   #16
Registered User
 
wingless's Avatar

Join Date: Aug 2013
Boat: 2000 Searay 380 Sundancer
Posts: 487
Re: LED Drivers

Yes, to measure the wattage being delivered to the lamp assembly, first connect the lamp to the driver, apply power and use a multimeter to measure the voltage at the lamp pigtail. Then, measure the current delivered to the lamp. Have one lamp pigtail wire remain connected and put the multimeter in series w/ the series w/ the second pigtail wire to measure the current.

Multiply the measured voltage times the measured current to get the measured power.

If the objective is to replace the universal AC voltage driver w/ a driver appropriate for the DC voltages on a boat, 10.5 - 15 VDC, then my recommendation is to disassemble the lamp assembly. Determine the schematic for the internals of the lamp, then select an appropriate driver configuration.

It is possible and reasonable to create a DC driver circuit that only gets warm, not hot, depending upon the existing fixed lamp configuration.
__________________

__________________
2000 SeaRay 380 Sundancer Mercruiser
454 MAG MPI Horizon 380hp / Westerbeke 7.0KW BCGB
many cool mods
wingless is offline   Reply With Quote
Old 20-05-2014, 20:46   #17
Registered User
 
wingless's Avatar

Join Date: Aug 2013
Boat: 2000 Searay 380 Sundancer
Posts: 487
Re: LED Drivers

Quote:
Originally Posted by mrlee View Post
Check these out...
New 10W Underwater RGB Light LED Remote Control Spot Light Lamp waterproof
I wouldn't get the RGB-multi color- option again...There is another piece you have to buy to make the remote work so just get the white...These lights are very well constructed and they work well...12V DC!!! I have 4 for my shroud downlights. and maybe 2 installed as flush mount transom lights...It would be east to french them into a transom...
There is no way I would ever put this waterproof light underwater on my boat. There is no way I would ever consider Frenching this lamp into my transom.
__________________

__________________
2000 SeaRay 380 Sundancer Mercruiser
454 MAG MPI Horizon 380hp / Westerbeke 7.0KW BCGB
many cool mods
wingless is offline   Reply With Quote
Old 20-05-2014, 20:54   #18
Registered User

Join Date: Apr 2011
Location: Gulf and Caribbean
Boat: Irwin 30
Posts: 264
Send a message via Skype™ to mrlee
Re: LED Drivers

Ok, thank you...now I see my mistake with measuring the amps...these lights are just 3-3W or 4-3W, or 5-3W Leds in series. they are pasta'ed to a heat sink and that's it...the driver does the rest. I figure that if the V dc and the amps multiply to the correct Watts...I should be ok. I don't think the voltage fluctuations will make a difference...as a matter of fact, I am now online with anotherelectronics guy who tells me the same...the amps are the key to LED life and sustainability.
I will check the amps manana first thing....hey, if I know the amps and the watts...I'll know the voltage!!! kinda wierd to think that way, but this has NOT been a very pragmatic affair so far.
Can I use a driver a little larger and use a resistor to drop the amperage? What about caps in a driver to sustain current flow?
One way or the other.....I want to make some LED kits for my friends' boats...I have even seen the drivers now are all dimmable...what does that tell ya??
Thanks for all your help...I'll do the amps manana first thing.
Peace
__________________
mrlee is offline   Reply With Quote
Old 20-05-2014, 21:12   #19
Registered User

Join Date: Apr 2011
Location: Gulf and Caribbean
Boat: Irwin 30
Posts: 264
Send a message via Skype™ to mrlee
Re: LED Drivers

I hear ya...I am in no way going to put it underwater...I just thought the underwater feature was pretty convenient...it will be a nice night dive light or when I need the dinghy etc...Not for below the surface...I see your point...
__________________
mrlee is offline   Reply With Quote
Old 20-05-2014, 21:30   #20
Registered User

Join Date: Apr 2011
Location: Gulf and Caribbean
Boat: Irwin 30
Posts: 264
Send a message via Skype™ to mrlee
Re: LED Drivers

do you have any experience with one of these?
5A Adjustable Power DC-DC Step-down Charge Module LED Driver With Voltmeter
It looks ok, but what do I know...
Thanks again
__________________
mrlee is offline   Reply With Quote
Old 21-05-2014, 14:32   #21
Registered User

Join Date: Apr 2011
Location: Gulf and Caribbean
Boat: Irwin 30
Posts: 264
Send a message via Skype™ to mrlee
Re: LED Drivers

Ok...here are the numbers...9Watt LED- V-9.46 @ 300mA
12W LED- V-12.86 @ 2.98mA
15W LED- V-16.59 @ 300mA
Here is what I learned last night...the mA are per LED chip...hence 9W-900mA;
12W=1200mA; and 15W=1.5A
Now I see my mistake...I was trying to raise the amperage and not the volts...If I raise the amps I'll burn my LEDs up...Now this won't be so hard...
Just a note, the 15W LED you pictured is different than the ones I found for the boat...the heat sink on mine is twice as long as the one pictured. I am also thinking about using ALL 15W led fixtures and eliminating 2 chips for 9Watt and 1 chip for 12Watt and keep the nice big heat sink...with the small fan I have added it'll be ok... a little extra work for some peace-of-mind...
I am pretty pleased with what I have to go on now...THANK YOWingless for the help..I ddn't know how to check the amps...DUH!!
I started the cases today and by Monday I hope to have one in prime. The LEDs angle, so I am angleing them at a 55-65 degree angle which will give more lightable access. I'll try to post some pix so you guys can see what I'm doing...
One techy question....If the driver is 3 feet from the LED and I use 18guage tinned wire...will voltage drop be an issue??? As you know, the LEDs have 24 guage silicone wire...I will crimp and then solder the connections for these.
Thanks again...God Bless
__________________
mrlee is offline   Reply With Quote
Old 21-05-2014, 17:05   #22
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
LED Drivers

mrlee, do t take this the wrong way , but as a long time practising EE, I've read through posts an I dont quite follow what you are trying to do. Your mixing up all sorts of half truths.

To drive LEDs , you have to stay within their specified spec limits, including peak forward current , voltage, reverse voltage , junction temperature ( hence power/ heat dissipation) exceeding the data sheets absolute maximum ratings will typically cause instant failure , while stressing the device close to its limits will tend to cause early mortality or reduced MTBF.

For example on a boat, even though you generally have fairly constant voktage, load dumping spikes can cause high voltages then if passed through the led driver can weaken or kill LEDs, irrespective of driver configuration


Constant current led drivers are merely one way to ensure LEDs remain in spec, that method has advantages and disadvantages. Good led drivers will also handle led ageing and other side effects as well.

The other thing to bear in mind is the quality of the led itself , in high power LEDs , Cree has a good reputation as has Philips ( via the luminex brand ) often particulary with Chinese stuff, you'll get ' Cree" LEDs that are not Cree at all.

Dave


Sent from my iPad using Tapatalk
__________________
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! - http://smartboats.tumblr.com
goboatingnow is offline   Reply With Quote
Old 21-05-2014, 17:41   #23
Head in a locker
 
Cavalier's Avatar

Cruisers Forum Supporter

Join Date: Dec 2010
Location: Houston, TX
Boat: Beneteau 461 47'
Posts: 879
Images: 1
Re: LED Drivers

Quote:
Originally Posted by goboatingnow View Post
mrlee, do t take this the wrong way , but as a long time practising EE, I've read through posts an I dont quite follow what you are trying to do. Your mixing up all sorts of half truths.

To drive LEDs , you have to stay within their specified spec limits, including peak forward current , voltage, reverse voltage , junction temperature ( hence power/ heat dissipation) exceeding the data sheets absolute maximum ratings will typically cause instant failure , while stressing the device close to its limits will tend to cause early mortality or reduced MTBF.

For example on a boat, even though you generally have fairly constant voktage, load dumping spikes can cause high voltages then if passed through the led driver can weaken or kill LEDs, irrespective of driver configuration


Constant current led drivers are merely one way to ensure LEDs remain in spec, that method has advantages and disadvantages. Good led drivers will also handle led ageing and other side effects as well.

The other thing to bear in mind is the quality of the led itself , in high power LEDs , Cree has a good reputation as has Philips ( via the luminex brand ) often particulary with Chinese stuff, you'll get ' Cree" LEDs that are not Cree at all.

Dave


Sent from my iPad using Tapatalk
+1 You can't cheap-out on the drivers or LEDs, it's a false economy, if not for replacement frequency but for the additional time taken to order, reinstall etc. the failed units.
__________________
"By day the hot sun fermented us; and we were dizzied by the beating wind. At night we were stained by dew, and shamed into pettiness by the innumerable silences of stars."
Cavalier is online now   Reply With Quote
Old 21-05-2014, 21:05   #24
Registered User

Join Date: Oct 2011
Location: Brazil
Boat: Velamar/German Frers 27
Posts: 44
Re: LED Drivers

Just buy the 12v cree Led lamps on any website. I have 10 of them for 3 years and none of them have failed yet. Buy a few more and don't waste your time nor your money on this marine Led lamp bs. Just be careful to choose with the pwm drivers not the resistor kind or you won't save any power at all.
With all the lights on, my ampmeter doesn't even move.

Sent from my SM-G900M using Cruisers Sailing Forum mobile app
__________________
Gabrieln is offline   Reply With Quote
Old 21-05-2014, 21:08   #25
Registered User

Join Date: Oct 2011
Location: Brazil
Boat: Velamar/German Frers 27
Posts: 44
Re: LED Drivers

Oh! I bought mine on some of those chinese free shipping website. I'm from Brazil, these things are expensive around here.

Sent from my SM-G900M using Cruisers Sailing Forum mobile app
__________________
Gabrieln is offline   Reply With Quote
Old 22-05-2014, 13:43   #26
Registered User

Join Date: Apr 2011
Location: Gulf and Caribbean
Boat: Irwin 30
Posts: 264
Send a message via Skype™ to mrlee
Re: LED Drivers

Hi guys..ok here is what I did today and it worked...I had bought some drivers for a 20WLED and they got too hot when connected. I hooked one to a 9W and adjusted it til I had 300mA going from the driver to the LED...It worked and ran for 2 hrs. with NO heat issues anywhere. I followed suit and tested the 12W and the 15W..ALL had the same GREAT results. So I have my drivers...This is the driver on ebay...
NEW DC-DC Adjustable Step-up Power Converter Module Output 5V-35V MAX current 3A search this on ebay
I made a quick box to mount these in today and when the glue dries manana I will hang it up and do a 15W LED test for 3 hours. I will add a small fan to these as well, so I think all my "freaking out" is over!!
I did learn that LEDs(the way they are constructed) are in parallel...this was my confusion...even though they are connected together in series...the AMPS increase for each one...NOT the voltage...I would have put 900mA into my 9Watter and fried it quickly...I'll try to show ya a pic of the box manana...not hard to make and totally functional...
Thank you all for all the input...I have taken a little from you all and used it.
God Bless
__________________

__________________
mrlee is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
woman drivers frankdeegan Seamanship & Boat Handling 20 07-07-2008 07:09
Drivers License vaccfam Rules of the Road, Regulations & Red Tape 10 19-05-2008 17:37



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 22:30.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.