Reply
 
Thread Tools Display Modes
 
Old 09-21-2017, 07:00 PM   #1
Veteran Member
 
f508's Avatar
 
City: Belmont, California
Country: USA
Vessel Name: MaryAnn
Vessel Model: 48 DeFever
Join Date: Jun 2017
Posts: 65
LED lights are flickering when the engines are running.

I replaced the engine room halogen bulbs and fixtures with some of those led light strips . The halogens don't respond to the voltage fluctuations but the LEDs do. Is this an alternator problem, or just one of those things one learns to ignore. I figured the house batteries would sort of buffer out the alternator cycles.

Anyway, should I care about this?

Thanks,

Frank
__________________
Advertisement

f508 is offline   Reply With Quote
Old 09-21-2017, 07:42 PM   #2
Guru
 
caltexflanc's Avatar
 
City: North Carolina for now
Country: USA
Vessel Name: Small Incentive
Vessel Model: Boston Whaler 130 Sport
Join Date: Aug 2011
Posts: 3,598
Read up on constant current LEDs, needed for boat type installations. Here is an admittedly self-serving, but accurate white paper by a supplier.

Constant-Current?
__________________

__________________
George

"There's the Right Way, the Wrong Way, and what some guy says he's gotten away with"
caltexflanc is offline   Reply With Quote
Old 09-24-2017, 12:26 PM   #3
Senior Member
 
City: Fairport
Country: United States
Join Date: Jan 2017
Posts: 311
Quote:
Originally Posted by f508 View Post
I replaced the engine room halogen bulbs and fixtures with some of those led light strips . The halogens don't respond to the voltage fluctuations but the LEDs do. Is this an alternator problem, or just one of those things one learns to ignore. I figured the house batteries would sort of buffer out the alternator cycles.

Anyway, should I care about this?

Thanks,

Frank
The before reference paper is a good one; but, if my LED's were unstable with the engine on and stable with engine off, I would have some concern.
Engine alternators have 3 phase ac then recified outputs. This should be a fairly clean waveform into a healthy battery system. LED's are optically, very fast devices, and don't have the thermal inertia that an incandescant lamp has.
One engine or two? LED issue only when a particular alternator is running? I'm thinking an alternator or regulator instability, that becomes visible with the LEDs. A good instrument for inspecting your alternator/regulator power quality is an oscilloscope.

I'll get into the LED driver technology if necessary, since I design linear and PWM type power supplies; but, in the end, the battery buss should not have short term instabilities (noise).
diver dave is offline   Reply With Quote
Old 09-24-2017, 01:43 PM   #4
Guru
 
Xsbank's Avatar
 
City: Duncan Cove, BC
Country: Canada
Vessel Name: Gwaii Haanas
Vessel Model: Vancouver Shipyards Custom Aluminum 52
Join Date: Sep 2013
Posts: 2,394
Did you get 12 volt leds or 10-20 volt? Leds are very intolerant to voltage and need "buck and boost" circuits to allow for the fact that your boat runs on 10 volts (if connected when you hit the starter) to 15+ while charging (you do disconnect for equalizing?) but 12 to 14.7 or so normally. Check the rated voltage?
__________________
"...Tongue tied and twisted, just an earthbound misfit..."

Don't believe everything that you think.
Xsbank is offline   Reply With Quote
Old 09-24-2017, 03:07 PM   #5
Veteran Member
 
f508's Avatar
 
City: Belmont, California
Country: USA
Vessel Name: MaryAnn
Vessel Model: 48 DeFever
Join Date: Jun 2017
Posts: 65
They are the 12 volt LED lights that are on the sticky tape. And they are stable with the engines off. That is what I was wondering about. They seem to be sensing a voltage variation from the alternators. Is that normal? I'm not much of an electrical guy, but I thought the house batteries would have sort of "buffered" any voltage variation.

Next time I run the engines I check and see if isolates to one of the alternators.
f508 is offline   Reply With Quote
Old 09-24-2017, 04:54 PM   #6
TF Site Team
 
FlyWright's Avatar
 
City: California Delta and SF Bay
Country: Sacramento, CA, USA (boat in Vallejo)
Vessel Name: FlyWright
Vessel Model: Marshall Californian 34 LRC
Join Date: Apr 2008
Posts: 10,028
If you used any of those clip-on connectors on the strip, you could have a bad connection affected by the engine vibrations. I have a finicky one in my home kitchen that I have to fiddle with.
__________________
Al

Custom Google Trawler Forum Search
FlyWright is offline   Reply With Quote
Old 09-24-2017, 06:25 PM   #7
Senior Member
 
City: Fairport
Country: United States
Join Date: Jan 2017
Posts: 311
If you have a DMM, a dc and a ac reading may be illuminating.
diver dave is offline   Reply With Quote
Old 09-24-2017, 08:25 PM   #8
Veteran Member
 
City: Great Lakes
Country: USA
Join Date: Aug 2017
Posts: 75
I've had bad luck with simple 12V strip lighting. In fact all applications have failed in short order. So then I bought a cheap buck stabilizer on line and that failed out of the box. I suspect it would have been "noisy" in the RF sense anyway. My current approach is the flat 12V arrays sold at Menards for $5 that plug into the old puck style halogen fixtures scattered around the boat. They seem to have some built in circuitry...no idea what. But for a five spot, I'll give 'em a shot.
Rufus is offline   Reply With Quote
Old 09-24-2017, 09:28 PM   #9
Guru
 
City: kemah
Country: USA
Join Date: May 2015
Posts: 968
try a simple hash filter for alternators. It will smooth out the output of it.

https://www.google.com/search?q=alte...w=2049&bih=906

You can "bulk" filter for all dc loads with a big amperage filter, or just filter for the led lights themselves with a lower current and lower cost filter.
__________________

what_barnacles is online now   Reply With Quote
Reply

Thread Tools
Display Modes

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





All times are GMT -5. The time now is 07:00 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012