Home > Maintenance & Modifications > LED light bar - Christmas pressy to myself |
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Naks Member Since: 27 Jan 2009 Location: Stellenbosch, ZA Posts: 2635 |
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 -- 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 |
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26th Apr 2012 8:26am |
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Go Beyond Member Since: 30 Jan 2012 Location: Headcorn, Kent Posts: 6678 |
Nearly half price then
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26th Apr 2012 8:32am |
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Naks Member Since: 27 Jan 2009 Location: Stellenbosch, ZA Posts: 2635 |
Yep, but found a local supplier at just R6K: http://shop.futurelight.co.za/pJI03/120W-LED-Off-Road-Light.aspx -- 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 |
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26th Apr 2012 8:37am |
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Go Beyond Member Since: 30 Jan 2012 Location: Headcorn, Kent Posts: 6678 |
Which equates to exactly the same price as our lightbars if you were in the UK
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26th Apr 2012 8:44am |
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leeds Member Since: 28 Dec 2009 Location: West Yorkshire Posts: 8580 |
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 Brendan |
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26th Apr 2012 8:44am |
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leeds Member Since: 28 Dec 2009 Location: West Yorkshire Posts: 8580 |
Thanks Pete,
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
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 Brendan Brendan |
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26th Apr 2012 10:00am |
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XS Pete Member Since: 13 Jan 2011 Location: Suffolk Posts: 632 |
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 |
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26th Apr 2012 10:46am |
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bpman Member Since: 21 May 2008 Location: Oslo Posts: 8069 |
They have a worldwide supply network including UK, Spain, Germany and NORWAY |
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26th Apr 2012 11:39am |
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Go Beyond Member Since: 30 Jan 2012 Location: Headcorn, Kent Posts: 6678 |
Where did you order it from then ?
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26th Apr 2012 11:41am |
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bpman Member Since: 21 May 2008 Location: Oslo Posts: 8069 |
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 |
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26th Apr 2012 11:47am |
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leeds Member Since: 28 Dec 2009 Location: West Yorkshire Posts: 8580 |
Once again,thanks Pete
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 |
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26th Apr 2012 12:48pm |
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bpman Member Since: 21 May 2008 Location: Oslo Posts: 8069 |
bit like cranking amps, cold cranking amps relating to batteries |
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26th Apr 2012 6:30pm |
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