Hello All,
I am finishing up a project using Cree LED's for a reef tank. I have a large majority of the electronics done except for one section: LEDs for aesthetics.
I have a total of 3 separate strings that I am working with: Whites, Royal Blues and Cool Blue. All of these will be run on Meanwell ELN 60-48s. I had looked into a CAT4101 build, but it was going to cost just as much to make it as it was to buy the meanwells, so I went with them. The only thing I did not realize was my Cool Blues (6 LEDs total in the string) have too low voltage to run on the minimum 24V needed for the constant current power supply. I had considered buying a buckpuck to drive these but this requires a DC converter which is why I went with the Meanwells-converted straight from mains.
First of all, at 350mA, the LEDs run at 3.2v each (19.2V total), which will more than likely be way too high of a current for their purposes (probably run at 100-200 mA). So, I'm looking for either a method to drop about 10V (to be safe) using these constant current regulators.
Second, this setup runs with a dimmer effect at the beginning and end, ramping up/down the the light cycle as controlled by the microcontroller. Therefore, the current will be changing during this ramp up/down process.
I had thought of using a Zener as a shunt, and stumbled across this link that talks about using a zener, resistor and transistor to regulate the voltage. Would this work for my purposes, or is there a simpler/cheaper method to drop an accurate voltage from variable 50mA-200mA?
I am finishing up a project using Cree LED's for a reef tank. I have a large majority of the electronics done except for one section: LEDs for aesthetics.
I have a total of 3 separate strings that I am working with: Whites, Royal Blues and Cool Blue. All of these will be run on Meanwell ELN 60-48s. I had looked into a CAT4101 build, but it was going to cost just as much to make it as it was to buy the meanwells, so I went with them. The only thing I did not realize was my Cool Blues (6 LEDs total in the string) have too low voltage to run on the minimum 24V needed for the constant current power supply. I had considered buying a buckpuck to drive these but this requires a DC converter which is why I went with the Meanwells-converted straight from mains.
First of all, at 350mA, the LEDs run at 3.2v each (19.2V total), which will more than likely be way too high of a current for their purposes (probably run at 100-200 mA). So, I'm looking for either a method to drop about 10V (to be safe) using these constant current regulators.
Second, this setup runs with a dimmer effect at the beginning and end, ramping up/down the the light cycle as controlled by the microcontroller. Therefore, the current will be changing during this ramp up/down process.
I had thought of using a Zener as a shunt, and stumbled across this link that talks about using a zener, resistor and transistor to regulate the voltage. Would this work for my purposes, or is there a simpler/cheaper method to drop an accurate voltage from variable 50mA-200mA?