high powered led driver circuit...

[bassboi]

hey all...

i'm currently trying to figure out a way to use several LEDs as the lighting for my aquarium, but I cannot seem to find an effective power source, or circuit.

the LEDs I found which seem nice enough to use are rated at 3.7v 1A... and I need to use about 7 of them.

they're also rated at 3.5v 700mA, and 3.3v 350mA, but I need a high color temperature which is outputted by the LED when used with high currents.

I may also need a few LEDs with lower current, like the 3.5v 700mA rating, to also have a couple lights at a cooler temperature for plant growth

any ideas?

 

[Sceadwian]

Try google, or searching the forums here. This question has been answered more than once.

 

[Hero999]

It has been discussed before but finding it can be a pain. I had to look through my attachments to find a suitable thread.
https://www.electro-tech-online.com/threads/best-way-to-power-a-white-led.30656/

https://www.electro-tech-online.com/attachments/edn-switch-constant-current-png.13319/

 

[neon]

source? any AC/DC source will sufice. they are diodes 1000v 10000v will work as long as you limit he current to a safe dissipation level. ac will work too but remenber to add a diode in series to surpass the reverse voltage breakdown . these diodes can only sustain very low reverse voltage before poof. if you have a low voltage tranformer like for a fone charger you can use it. the LEDS usualy requires 10ma and 2 -3 volts to light up. so no matter what is the voltage output limit the current to 10ma with a resistor. how many can you instal that depends on your tranformaer current capability.ea. 12 v use 4 leds and and 200 ohms you can add more and more of these setup until the tranformer cannot handle the current. do not use 120ac that is dangerous for aquarium. but 12 v will not bother you . and finaly i believe that the light should not be LEDS but ultraviolet to simulate the sun for healthy fishes.

 

[audioguru]

Hello Neon,
You didn't read about the powerful LEDs he has. 1A, not just 10mA.

 

[ronsimpson]

I just turned on a board using 4+4, 1amp LEDs. The current is controlled by a LM3410. I only have 4 LED on now. I will try to get all 8 running soon. The LEDs get very hot. I need to add more heatsinking.

 

[Ubergeek63]

HV9910 is designed to do just that

 

[bassboi]

Thanks for the replies, and I took some advice here and I found this:

**broken link removed**

With a couple of questions...

Lets say I'm using like 2 LEDs in a series with this circuit... can I add more in parallel, or would I have to build the circuit again for more LEDs?

 

[bassboi]

I took some advice here, and did a google, and came across this:

**broken link removed**

I only have one question...

Can I run some LEDs in parallel on this circuit, or would I have to build the circuit again for however many LEDs I need?

 

[audioguru]

LEDs each have a slightly different forward voltage. So if they are connected in parallel the one with the lowest voltage will hog most or all of the current and burn out. Then the other LED will have all the current and it will also burn out.
Manufactured products have LEDs in parallel because they measure the voltage and sort the LEDs into groups that have the same voltage.

If a regulated current circuit can operate from a higher voltage then LEDs can be connected to it in series then each LED in the series string receives the same current.
Each string needs its own current regulator.