High power LEDs differ from regular LEDs in a number of respects. Firstly, current regulation using resistors is impractical so it's necessary to use a switched mode voltage and current regulator. Secondly, they generate heat which must be drawn away from the LED to prevent damage by overheating.
By Julian
Youtuber, shed dweller, solar charge controller aficionado
From 230v ac I need to connect 20 1 w led so I think one rc circuit with buck converter I can use ? 66 volt 300ma I require
Hi Julian! thank you for your videos , why do we need to regulate the driver voltage output if the current is already regulated ? thank you
P =V x I, so if it's 1 W, then 1/8.7 gives a current of 114mA. Not 300mA. Then P = I squared R, 1W = 0.114 x 0.114 x R, R =75 ohms. Use this resistor and you have no problems. You cooked the last one because you used a wrong resisitor. 33ohms is ~half the size required. Im not sure where you got the 300mA current from? I've used this method for years on all my led installs and never had a problem cooking any resistor, and the leds run cold as ice. I also don't use the Vf. I use the full voltage in case of a failure. So I would use 12V as the Voltage, not 8.7. Ive got my whole shed setup running 24 V leds on 2 12 V car batteries of 25Ah each in series and my house with 12 V batteries in parallel with 12V 6.5 W leds. I measured the current through the circuit first in the shed for each array and saw it was 600mA, and using the power calculation worked out its 14.4 W. Working it out is gives a value of 40ohms. So then the resistor I use is 15W and couldn't find a 40 so I use 44ohms. And resistor are cheap, so a little bigger is not an issue. I think they were $1.80AUS each. Ive had no issues with house or shed so hope I'm not doing anything wrong !! 😬
Hi, my microscope led is the 3 watt star model. I burnt out the original circuit board because I plugged a 12 V wall charger instead of the recommend 5 V. So my question is can I use this led with a buck converter to allow a normal generic 12v to power it? Also need a dimmer switch attached to control brightness. Does anyone know how to go about this ?
Hi there, can you please tell me what will happen if one string of led connected to CC driver fails to operate, as per my research it'll divide the total current into remaining string which as a result would damage them causing the whole system down. plzzzzzzzzzzzzzzzzz help
The old ones are the best…
I meant the video not you. 😉
Hi, I have current source 900ma box. Input ac 220, output 12v labeled – Led and + Led. My Led 3 w, star Led same as on your video. My question can connect this Led direct as the box labeled which in this case I’m putting 12v on the Led or I should connect a series resistor which can drop the voltage across the Led? Thanks
Dear Julian
Great videos you have.
what>model Buck>converter is this.
The>Current buck converter ?
Gr
Hello, Thank you for the video! Does the output current remain constant throughout the battery's voltage drop (without adjusting)? Thanks!
Well done
Which module I can Use for drive 12V Led Strip on 12V Battery?The Linear Lm317 have too much Drop Voltage.Thanks for your Videos
Great video, just what I was after. One thing Im not sure of though is I want to have three LEDs that can be independently switched. Can I put three 1W LEDs in parallel and use a relay to turn some on and off or does it need to be all on or all off on the output?