Advice needed for an 100W LED

[Jouellet]

OK, I bought a couple of 100W LEDs. They have the following specs::

DC32-36V 3500mA

Since I want to use them in my truck, I also bought a couple of 150W, DC-DC converter, 10-32V-in/12-35V-out.

Now, I'm pretty sure that if I connect them directly to the output of the converter, that's not the best idea !

I have seen a guy that built a huge flashlight, feed by 36V, using 100W LED, with only a 1 Ohm resistor in series with the LED.

Is that enough ?

Anyone has a schematic of a good LED driver, that could handle 100W ???

I saw a few circuits on Google, but most of them had a PWM input, which I don't want....

For those who might mention it, YES, I have planned some water cooled heat sink for the LEDs !!!!

TIA

 

[BobK]

If you DC to DC converter has a current limit, set the current for 3500mA and connect it directly to the LED. Since the LED is rated at 32-36V and the converter has a max output of 35V, it might not be able to achieve the full current.

Bob

 

[Herschel Peeler]

OK, I bought a couple of 100W LEDs. They have the following specs::

DC32-36V 3500mA

Since I want to use them in my truck, I also bought a couple of 150W, DC-DC converter, 10-32V-in/12-35V-out.

Now, I'm pretty sure that if I connect them directly to the output of the converter, that's not the best idea !

I have seen a guy that built a huge flashlight, feed by 36V, using 100W LED, with only a 1 Ohm resistor in series with the LED.

Is that enough ?

Anyone has a schematic of a good LED driver, that could handle 100W ???

I saw a few circuits on Google, but most of them had a PWM input, which I don't want....

For those who might mention it, YES, I have planned some water cooled heat sink for the LEDs !!!!

TIA

I don't know if it applies to your LEDs but I use a lot of high wattage LEDs (10 to 20 watt range) and I just use a regulated voltage, adjustable when desired. The 10 watt LEDs are said (by the distributor) to run on "9 V to 12 V". 10 Watts I take to mean at about 1 Amp. For a dimmer I use a pot, op amp and power transistor (Darlington).
Yes, good designing says "current limiting". If your objective is to get maximum brightness and longest life, that is certainly the way to go.

 

[BobK]

The spec for the LED, 32-36V 3500mA does not mean that it can be run from a voltage source of anywhere between 32 and 36V. It means that it should be run at 3500mA, and the voltage needed will be somewhere in the range of 32 to 36V. This is why you want a current source to run it, the driver must adjust the voltage to control the current, and it must do so over a range of temperatures.

Bob