I am building a LED array and am unsure of if I have been given bad information. I was told i can use a PC PSU to power my LED array safely using resistors and rheostats to dim them. After doing some research i have found out that LEDs need constant current more than constant voltage – a PC PSU is constant voltage.
The LEDs I purchased are all 10 watts each. I will be running 11 of them and would like to use one power supply if possible. The specs on the different LEDs and hardware are below:
4 x White
Foreward voltage: 9-11v
Foreward current: 900 – 1050 mA
4 x Blue
Foreward voltage: 9-11v
Foreward current: 900 – 1050 mA
1 x Violet
Foreward voltage: 9.5-10v
Foreward current: 900 – 1050 mA
1 x Green
Foreward voltage: 9-12v
Foreward current: 900 – 1000 mA
1 x Red
Foreward voltage: 6-8v
Foreward current: 900 mA
11 x 2 Ohm Resistor
4 x 1 Ohm rheostat
My plan was to power all of the LEDs on the 12v line, use a resistor for each LED and a rheostat for each color wired in series (blue and white use 1 rheostat). Red would use the 5v line and a resistor and rheostat.
My question is can i use a PC PSU? Is it a bad idea considering its not constant current?
Would this setup work or would it burn up the LEDs? Would there be a better way to wire or drive this? If so what kind of a driver would i need?
Best Answer
"Can I use a PC PSU?" Yes, make sure there is a load and you are connecting the signal lines properly (this information is readily available on the internet)
"Is it a bad idea considering its not constant current?" Yes
"Would this setup work or would it burn up the LEDs?" It would work fine as long as you don't exceed the ratings of the LEDs
"Would there be a better way to wire or drive this?" Yes
"If so what kind of a driver would i need?" A constant current LED driver: https://www.google.com/search?q=constant+current+LED+driver#q=constant+current+LED+driver&tbm=shop (assuming you are not willing/able to build a circuit yourself)