New wicked LED lighting hotness

[GrimmJeeper]

gust looked at the website, pricey $25 for ONE! take a look

not too bad once you think about how much brighter they are, and thier resistance to vibration... i know i carry 2 extra of each bulb wrapped in bubble wrap in my glove box. seems like the filament in at least one bulb goes out every time i'm in the desert.

 

[FatCity Ryan]

When are we going to see pics of the new car Diesel?

 

[DieselSJ]

When are we going to see pics of the new car Diesel?

As soon as I can get Randy's kid to get over there and take some!

 

[HeepSpeed]

sooooo? pics?

 

[Billy1911]

The only problem with LED's is they dont put out the light far enough a head to go fast.

 

[crazyjim]

The only problem with LED's is they dont put out the light far enough a head to go fast.

For a Jeepspeed, I'd venture to say they're more than enough. I know guys who run them on 14 trucks doing 90+ and can't outrun them.

 

[DieselSJ]

The only problem with LED's is they dont put out the light far enough a head to go fast.

There are at least 2 trophy truck teams that will argue that point. If you believe what you say, then you haven't seen LEDs lately.

 

[julio_a]

There are at least 2 trophy truck teams that will argue that point. If you believe what you say, then you haven't seen LEDs lately.

andy mcmillin is one i believe. that guy is wicked fast!

 

[Los Lobos]

Diesel how is the light bar working for you?

 

[CherBear]

The only problem with LED's is they dont put out the light far enough a head to go fast.

Wouldn't that be determined by the reflector shape? That and the total wattage...?

 

[n1ywb]

Our plan is to run a single 50" on top (which is more light output than 5 HID), a 20" amber on the front for cutting through dust, and a 4" with a flood pattern in each headlight bucket. It is going to cut our power load for lighting from over 100 amps (HID draw between 15a and 20a each) to about 60 amps. That takes a huge load off the alternator. Plus we are saving about 50lbs (most at roof level), and we are going to have more usable light than we had before.

I am an ex-LED engineer. Here are some dirty little secrets about LEDs:

1. HIDs and fluorescents are both MORE efficient than high output LEDs
2. LEDs get less efficient as they get hotter
3. LEDs get hotter as they put out more light
4. LED manufacturers run them super hot so they can get lots of light
5. LEDs last a shorter time the hotter they get
6. LEDs put out less light the hotter they get, so Mfgs don't run them THAT hot

If you are really drawing less current, you are probably getting less overall light. See point 1. But if they have superior optics directing the light where you need it, it could still be an overall win.

Of course they have no filament to break; they are hands down more rugged than any glass bulb. And the industry continues to dump R&D money into them and they are continuously improving, so who knows, my info could be outdated.

You could always ask the flashlight nerds over on http://www.candlepowerforums.com

 

[CherBear]

I am an ex-LED engineer. Here are some dirty little secrets about LEDs:

1. HIDs and fluorescents are both MORE efficient than high output LEDs
2. LEDs get less efficient as they get hotter
3. LEDs get hotter as they put out more light
4. LED manufacturers run them super hot so they can get lots of light
5. LEDs last a shorter time the hotter they get
6. LEDs put out less light the hotter they get, so Mfgs don't run them THAT hot

If you are really drawing less current, you are probably getting less overall light. See point 1. But if they have superior optics directing the light where you need it, it could still be an overall win.

Of course they have no filament to break; they are hands down more rugged than any glass bulb. And the industry continues to dump R&D money into them and they are continuously improving, so who knows, my info could be outdated.

You could always ask the flashlight nerds over on http://www.candlepowerforums.com

Also, isn't the light output/ applied voltage curve, very not-linear?

I thought LEDs would put out very close to their maximum output at close to half of their maximum input voltage, any higher voltage just sort of heats up the diode while producing only smaller gains in output light.

 

[n1ywb]

Also, isn't the light output/ applied voltage curve, very not-linear?

I thought LEDs would put out very close to their maximum output at close to half of their maximum input voltage, any higher voltage just sort of heats up the diode while producing only smaller gains in output light.

Yes and no.

Most people think about power supplies in terms of volts. But with LEDs it's much easier to talk about current.

LEDs have a variable resistance. If you apply more voltage to them, their resistance goes down. Most power supplies are "voltage" supplies, EG a battery. But it's not really a CONSTANT voltage supply, there can be a big difference between full charge and dead.

Typically LEDs are driven from a CURRENT supply, IE a circuit designed to deliver a constant current rather than a constant voltage. The cheap ones just use a resistor in series with a voltage source, which wastes power and doesn't compensate for changes in the voltage source. Good circuits measures the current flowing through the LEDs, and adjust the current output to compensate, like a closed loop control system. Low efficiency circuits do this with a transistor, which acts like a variable resistor. The best, most efficient circuits do this using pulse-width-modulation.

Light output increases as current increases, up to a point. Beyond that, the LED gets hotter, and less efficient, and light output starts to decrease, and the LED die may be damaged. The precise nature of the curve depends on the LED and how it's heat-sinked.

 

[DieselSJ]

All I know is they kicked butt over our HIDs. Way more usable light. I have some in-car that I'll be posting shortly.

 

[Sig Ep Mock]

Over on Glamis Dunes.com we ran a side by side comparrison of HID and the Rigid LED's. The LED"s worked amazing and drew less power which was huge for the SXS's with small charging and battery systems. The LED throws out this amazingly wide and consistant light that doesn't get smaller as you get closer if that makes sense. Only down side in my experience is that they do not throw out light as far as HID's which can cause problems for vehicles with faster speeds off road. I personally like a mix of both. A couple spot HID's for long distance straight ahead and then the LED's for a super wide and useful light up close and out to about 100 feet. I will say that so far between 5 in our group running them not one has ever had a problem or breakage with the LED's. I can't say the same for our HID's and they are not the Kragen specials Now I just need to get a couple of the 10" LED's for the XJ to go with the HID's.


Just my $.02,

Chris

 

[Trail Ready]

but MAN are they $$$$$$$$$$

x2 that's what I was gong to say.I looked into getting them for my Duramax last year.

 

[Los Lobos]

I use 20" bars for side lighting. They light up everything around.

 

[kastein]

Yes and no.

Most people think about power supplies in terms of volts. But with LEDs it's much easier to talk about current.

LEDs have a variable resistance. If you apply more voltage to them, their resistance goes down. Most power supplies are "voltage" supplies, EG a battery. But it's not really a CONSTANT voltage supply, there can be a big difference between full charge and dead.

Typically LEDs are driven from a CURRENT supply, IE a circuit designed to deliver a constant current rather than a constant voltage. The cheap ones just use a resistor in series with a voltage source, which wastes power and doesn't compensate for changes in the voltage source. Good circuits measures the current flowing through the LEDs, and adjust the current output to compensate, like a closed loop control system. Low efficiency circuits do this with a transistor, which acts like a variable resistor. The best, most efficient circuits do this using pulse-width-modulation.

Light output increases as current increases, up to a point. Beyond that, the LED gets hotter, and less efficient, and light output starts to decrease, and the LED die may be damaged. The precise nature of the curve depends on the LED and how it's heat-sinked.

Gotta love the shockley diode equation! What kind of LED work did you do? I've always been interested in how the die frame / reflector is designed, since it appears that most of the light comes from the surface of the die and some is radiated out the edges but none is emitted out the back / below the plane of the PN junction. Seems like a properly designed die frame and plastic package could give nearly any light pattern desired.

Light is light, doesn't matter what it comes from so long as it has the same spectral content (approximately) and the same intensity at all the right angles. If someone were to design an LED lighting setup that would emit in the same pattern as the HIDs that "throw" light further out, it would perform just as well, photons are photons. My bet is that the HID lens assemblies are set up to put more of the light out above the centerline of the lenses (which thus goes further out from the front of the vehicle before encountering the ground) while the LEDs are a more even light distribution, which results in more light hitting the stuff that's closer in, giving the perception that they aren't "throwing" light as far.

</nerd crap no one cares about>