Is it really possible now? That is the question.
With that quest in hand I determined there were two drivers I have that are capable of driving more than 1+ Amps to a low Vf (~3.5V) LED like the new Seoul P7 LED.
The SOB is actually capable of doing more than 1 Amp if the step down ratio is high enough. An input voltage twice that of the output would allow nearly double that of the internal switch current limit which is around 1.5A. A four to one ratio of input to output would allow driving 4A to the output with ~14V input limit.
I just received a new sense resistor that is 0.027 ohms. This is almost 1/4 the value of 0.1 ohms and nets a regulated output of 1.8A on the SOB. Of course that means minimum input voltage is 7V or higher to stay in regulation and to keep the SOB input at around 1A or less.
I've have wired up four Cree P2 in parallel to simulate a 4 die Seoul P7 and am using that as my load for my test configuration.
With one 0.027 resistor I got 1.8A to the LED and I had the supply at 7V. Lower input voltages would still work it would only make the driver work harder and generate more heat. My recommendation is to keep input current max at 1A or so even though the IC is good for 1.5A.
To get 4A you would use two of these. I will try two now and see how it goes and post the results as well.
As for the second driver. That's the new Iracongi or Irakongi. I actually like the latter version. Iracongi is the tiny box jellyfish that are super tiny and super deadly.
The driver is a buck driver and is on a large rectangular board with a rotary switch. Currently it is targeted as the driver for the Makita LXT box that sits on top of the Makita Dock base.
Here's a picture inside the box to give you an idea of the size of the PCB.
The board provides three regulated level control with the rotary switch and is a true white balanced driver meaning low doesn't turn yellow. There is a buzz from the PWM in the current design on medium and low. The driver IC on this board is a beefy buck converter and the board input voltage limit with the correct high voltage capacitors can run off 36V.
This board could drive the Seoul P7 at almost 1:1 input to output voltage ratio. I would suggest a 2:1 input to output or 6-9V input range for a 4A output configuration.
When I get a chance I will test this board as well in a 4A output configuration.
Since Buck converters input to output ratio step down you can take any buck converter and with the proper modifications possibly get the same results. It doesn't just apply to these two drivers.
Thermal management of the driver and LED of course are utmost important as input/output powers go beyond 10W or more.
Wayne
With that quest in hand I determined there were two drivers I have that are capable of driving more than 1+ Amps to a low Vf (~3.5V) LED like the new Seoul P7 LED.
The SOB is actually capable of doing more than 1 Amp if the step down ratio is high enough. An input voltage twice that of the output would allow nearly double that of the internal switch current limit which is around 1.5A. A four to one ratio of input to output would allow driving 4A to the output with ~14V input limit.
I just received a new sense resistor that is 0.027 ohms. This is almost 1/4 the value of 0.1 ohms and nets a regulated output of 1.8A on the SOB. Of course that means minimum input voltage is 7V or higher to stay in regulation and to keep the SOB input at around 1A or less.
I've have wired up four Cree P2 in parallel to simulate a 4 die Seoul P7 and am using that as my load for my test configuration.
With one 0.027 resistor I got 1.8A to the LED and I had the supply at 7V. Lower input voltages would still work it would only make the driver work harder and generate more heat. My recommendation is to keep input current max at 1A or so even though the IC is good for 1.5A.
To get 4A you would use two of these. I will try two now and see how it goes and post the results as well.
As for the second driver. That's the new Iracongi or Irakongi. I actually like the latter version. Iracongi is the tiny box jellyfish that are super tiny and super deadly.
The driver is a buck driver and is on a large rectangular board with a rotary switch. Currently it is targeted as the driver for the Makita LXT box that sits on top of the Makita Dock base.
Here's a picture inside the box to give you an idea of the size of the PCB.
The board provides three regulated level control with the rotary switch and is a true white balanced driver meaning low doesn't turn yellow. There is a buzz from the PWM in the current design on medium and low. The driver IC on this board is a beefy buck converter and the board input voltage limit with the correct high voltage capacitors can run off 36V.
This board could drive the Seoul P7 at almost 1:1 input to output voltage ratio. I would suggest a 2:1 input to output or 6-9V input range for a 4A output configuration.
When I get a chance I will test this board as well in a 4A output configuration.
Since Buck converters input to output ratio step down you can take any buck converter and with the proper modifications possibly get the same results. It doesn't just apply to these two drivers.
Thermal management of the driver and LED of course are utmost important as input/output powers go beyond 10W or more.
Wayne
