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Naks



Member Since: 27 Jan 2009
Location: Stellenbosch, ZA
Posts: 2634

South Africa 2010 Defender 90 Puma 2.4 SW Alpine White
FCX.ME.UK wrote:
How do our prices compare Naks ? http://www.farrowsclassics.co.uk/alienXplorer-L-E-D-Lightbar.html



Rigid: approx ZAR 10,000 (excl shipping, customs duty & VAT). Close to ZAR14,000 incl.

FCX: approx ZAR 6,000 excl. Close to R8,000 incl.


still not possible to run that past SWAMBO Whistle --
2010 Defender Puma 90 + BAS remap + Alive IC + Slickshift + Ashcroft ATB rear
2015 Range Rover Sport V8 Supercharged



Defender Puma Workshop Manual: https://bit.ly/2zZ1en9
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Post #141843 26th Apr 2012 8:26am
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Go Beyond



Member Since: 30 Jan 2012
Location: Headcorn, Kent
Posts: 6678

United Kingdom 
Nearly half price then Mr. Green
Post #141844 26th Apr 2012 8:32am
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Naks



Member Since: 27 Jan 2009
Location: Stellenbosch, ZA
Posts: 2634

South Africa 2010 Defender 90 Puma 2.4 SW Alpine White
FCX.ME.UK wrote:
Nearly half price then Mr. Green


Yep, but found a local supplier at just R6K: http://shop.futurelight.co.za/pJI03/120W-LED-Off-Road-Light.aspx


Quote:
Extremely similar to the Rigid Industries E type LED bar except these use an polycarbonate, optical acrylic lens system.
A combination of Double row 3W Cree Led's, highly efficient design coupled with 99% optical lenses produces the brightest whitest light you have seen.
Length 55cm
Wattage 120 Watt (40 x 3W High Power CREE Chips)
Voltage 12v DC
Lumens 14000
 --
2010 Defender Puma 90 + BAS remap + Alive IC + Slickshift + Ashcroft ATB rear
2015 Range Rover Sport V8 Supercharged



Defender Puma Workshop Manual: https://bit.ly/2zZ1en9
Discovery 4 Workshop Manual: https://bit.ly/2zXrtKO
Range Rover/Sport L320/L322/L494 Workshop Manual: https://bit.ly/2zc58JQ
Post #141846 26th Apr 2012 8:37am
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Go Beyond



Member Since: 30 Jan 2012
Location: Headcorn, Kent
Posts: 6678

United Kingdom 
Which equates to exactly the same price as our lightbars if you were in the UK Thumbs Up
Post #141847 26th Apr 2012 8:44am
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leeds



Member Since: 28 Dec 2009
Location: West Yorkshire
Posts: 8580

United Kingdom 
For an explanation of raw and effective lumens have a read HERE


I must admit I get confused with some of the figures given for LED lights.

For instance

Lumen Volt / watts
14400 9V-36V 240w

11.56amp draw

What really confuses me is 240 watts having a current draw of 11.56 amps

Now normally POWER (watts) = Voltage x Current

With 240 watts and 11.56 amps gives a voltage of 20.76V

Now 240 watts at nominal 12 volts would have a current draw of 20 amps.

The difference in this current draw has serious implications on wiring, switches and fuse sizes.

Have had a quick look at some more figures for light bars. 139 watts with current draw of 9.6 amps which gives a voltage of about 14.5 volts. Now that is close to the standard output of a 12 volt alternator.

I am confused!

So what is the connection between voltage current and power where LED worklights are concerned?


I have just had a quick look at the JWSpeaker site and they give current draw @12 or 24 volts Thumbs Up

Brendan
Post #141849 26th Apr 2012 8:44am
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XS Pete



Member Since: 13 Jan 2011
Location: Suffolk
Posts: 632

England 2011 Defender 90 Puma 2.4 XS CSW Stornoway Grey
Bren,

Without seeing a schematic of the power supply that these units employ, it's impossible to say for sure, but I would guess that many of these don't leave the LEDs on constantly, and actually pulse them at a frequency above that perceptible to the human eye (>60Hz), for maximum efficiency (and higher light output).

Depending upon how the power supply is configured (smoothing etc) the load on the battery may not be constant like pure DC, and may be more AC like (possibly quite spikey), therefore, your generic VA calculation will be wrong as this only works for pure DC loads.

Pete
Post #141852 26th Apr 2012 9:31am
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leeds



Member Since: 28 Dec 2009
Location: West Yorkshire
Posts: 8580

United Kingdom 
Thanks Pete, Thumbs Up

so simple resistive power comsuption does not work with LED lights

However must admit I still think that JWSpeaker way of doing it is much clearer

Quote:


Technical Specifications
4-Module 12V Version
12V DC Input
8.000 Amps @ 12V DC
Raw Lumen Output: 4,400
Effective Lumen Output: 2,640


4-Module 24V Version
24V DC Input
4.800 Amps @ 24V DC
Raw Lumen Output: 4,400
Effective Lumen Output: 2,640





I did wonder why the 24v current rating was not half that of the 12 volt one but now I understand.

Now question for the multivoltage LED lights say 6/50 or 9/36 volts what voltages are the current draw given at? OK one would assume 12 volts but that could be dangerous as assumptions can make an ass..................etc

Thanks Pete Bow down


Brendan

Brendan
Post #141854 26th Apr 2012 10:00am
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XS Pete



Member Since: 13 Jan 2011
Location: Suffolk
Posts: 632

England 2011 Defender 90 Puma 2.4 XS CSW Stornoway Grey
Bren,

On devices which can operate at multiple voltages, the standards generally dicate that that the specified maximum operating current is worst case. I.e. if 10A is specified for something which can operate between 12 & 48V, the actual operating voltage is pretty irrelivant, they are simply stating that throughout this range 10A will not be exceeded. It is this which is really important for cable sizing and fuse rating.

The problem starts (as you have discovered) when devices use 'switching power supplies' to cover a broad range of operating voltages, and the consumption is stated in Watts. There is not necessarily a linear correlation over the whole operational range of voltages, and therefore, if the worst case current is not stated, without actually testing the device over its operating range and looking with a scope (or Wattmeter), it's impossible to know exactly.

Pete
Post #141864 26th Apr 2012 10:46am
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bpman



Member Since: 21 May 2008
Location: Oslo
Posts: 8069

2008 Defender 110 Puma 2.4 SVX Station Wagon Santorini Black
FCX.ME.UK wrote:
I see D44 have stopped supplying the 'Rigid Industries' LED lightbars, have you ordered yours direct from the States ?


They have a worldwide supply network including UK, Spain, Germany and NORWAY Very Happy
Post #141870 26th Apr 2012 11:39am
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Go Beyond



Member Since: 30 Jan 2012
Location: Headcorn, Kent
Posts: 6678

United Kingdom 
Where did you order it from then ?
Post #141872 26th Apr 2012 11:41am
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bpman



Member Since: 21 May 2008
Location: Oslo
Posts: 8069

2008 Defender 110 Puma 2.4 SVX Station Wagon Santorini Black
Raw vs Effective ... from JWS site

Raw The Raw Lumen output is calculated by simply taking the number of LEDs in a lamp and multiplying by the LED rated output.

Example:

8 LEDs rated at 100 Lumens per watt
8 x 100 = 800 Lumen


Effective The Effective Lumen output is calculated by taking the Raw Lumen value and subtracting the Thermal, Optical and Assembly Losses.

Example:

Raw Lumens = 800
Less - Thermal, Optical & Assembly Losses = 40%
Effective Lumens = 480 Lumens

so running LEDS in cold climates and/or on the front of vehicles works well Thumbs Up
Post #141874 26th Apr 2012 11:47am
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leeds



Member Since: 28 Dec 2009
Location: West Yorkshire
Posts: 8580

United Kingdom 
Once again,thanks Pete Thumbs Up

With low wattage LED say 3 watts or less the actual current is not a major consideration.

However with the increase of high power LED lights, with some light bars going up to several hundreds of watts, getting the cable, switch and fuse rating is correct becomes more important.

Now just using the word maximum current would solve a lot of potential confusion.

Yes I do like the simple, clear informative way JWSpeaker presents the information.

It is a pity that we could not have a simple standard way of presenting information to consumers so that consumers can make an informed choice.

Must admit I have learnt a lot, cheers Pete.

Brendan
Post #141881 26th Apr 2012 12:48pm
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bpman



Member Since: 21 May 2008
Location: Oslo
Posts: 8069

2008 Defender 110 Puma 2.4 SVX Station Wagon Santorini Black
leeds wrote:
It is a pity that we could not have a simple standard way of presenting information to consumers so that consumers can make an informed choice.



bit like cranking amps, cold cranking amps relating to batteries
Post #141958 26th Apr 2012 6:30pm
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