[RE-wrenches] DC power for LED lighting

Fri Dec 16 13:36:13 PST 2011

Jeff,

Contact Jason at Mid-America Advanced Power Solutions.

http://www.maaps.us/ 

They manufacture a variety of high-power LED equipment and can likely
provide assistance.  They're also a solar/PV/RE installer and can converse
on that level as well.

Dan

-- On Fri, 12/16/11, holtek at sbcglobal.net <holtek at sbcglobal.net> wrote:

From: holtek at sbcglobal.net <holtek at sbcglobal.net>
Subject: Re: [RE-wrenches] DC power for LED lighting
To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
Date: Friday, December 16, 2011, 3:16 PM

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Jeff,
My experience with LED lighting is limited, but in the systems I have done 
I included a DC-DC voltage regulator as the voltage range was +/- 10%. Had no 
issues with manufacturer (since gone out of business - ouch). The 
system has worked fine for going on 6 years.

Holt E. Kelly
Holtek Fireplace & Solar Products
500 Jewell 
Dr.
Waco TX. 76712
254-751-9111
www.holteksolar.com

  ----- Original Message ----- 
  From: 
  Jeff Yago 

  To: conradg at cape.com ; 'RE-wrenches' 
  Sent: Friday, December 16, 2011 12:24 
  PM
  Subject: Re: [RE-wrenches] DC power for 
  LED lighting

  I 
  have a local sign company that asked is to provide a solar lighting system for 
  a double sided sign they were building for a large retirement community 
  entrance.  We have provided many solar lighting systems just like this 
  over the years and sent them several examples.  All our systems have been 
  turn-key in that we provided the 12 VDC ground mounted LED flood lights with 
  the separately pole mounted solar module(S) and battery/controller 
  box.   We “assumed” when we told them our system includes the LED 
  lights that they understood that we were providing the lighting.  

  Unfortunately, 
  when we arrived on the site to install the solar system, they said they did 
  not need our LED lights, they wanted us to power the LED lights inside the 
  sign.  We opened up the signs and found two 120 VAC electronic LED power 
  supplies.  Each was clearly labeled as providing a maximum of 5 amps at 
  12 VDC output, and each powered a separate string of about 150 tiny plastic 
  “blocks” and each block contained 2 small LED lamps.   We 
  immediately advised the client that the solar  system was designed to 
  power our two  12 VDC flood lights and we would have to totally tear out 
  what we had just installed and go to a much larger system that included an 
  inverter, larger array, 120 VAC timing device, and replace the 2 conductor DC 
  underground wiring  with 3-conductor AC wire and all  this would 
  really increase $$$. 

  I 
  said as an alternative, why can’t we just cut out the two electronic120 VAC 
  input  LED drivers since we are providing well regulated 12 VDC power 
  direct from the GEL battery.   He checked with their LED lamp 
  supplier and they said they strongly disagree and will void warranty.  
  Since we are talking about almost 300 total LED devices my client is afraid to 
  give us the OK, even though we did run them overnight and everything worked 
  just fine.   As I recall, an LED needs something in the circuit to 
  limit the amp current, not the voltage flowing through it,  or it will 
  just get brighter and brighter and then fail.  However, I thought almost 
  all strings of separate LED lights already had some kind of regulator built 
  into each light block otherwise those near the end of the string would be less 
  bright than those near the power source.    Is this 
  correct?? 

  Finally, 
  if strings of LEDs require some kind of voltage or current regulator, I can’t 
  believe they all have to run on 120 VAC as indicated by this LED manufacturer 
  who offers no alternative.    Any LED experts out there that 
  can point me to some type of DC-to-DC converter or current  regulator 
  that can replace these 120VAC LED drivers? 

  Thanks, 

  Jeff 
  Yago 

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