hey all I have the following: 100 13000mcd 5mm WHITE LED's Emitted Colour : WHITE Size (mm) : 5mm T1 3/4 Lens Colour : Water Clear Peak Wave Length (nm) : N/A Forward Voltage (V) : 3.2 ~ 3.8 Reverse Current (uA) : <=30 Luminous Intensity Typ Iv (mcd) : Average in 13000 Life Rating : 100,000 Hours Viewing Angle : ±10° Absolute Maximum Ratings (Ta=25°C) Max Power Dissipation : 80mw Max Continuous Forward Current : 30mA Max Peak Forward Current : 75mA Reverse Voltage : 5~6V Lead Soldering Temperature : 240°C (<5Sec) Operating Temperature Range : -25°C ~ +85°C Preservative Temperature Range : -30°C ~ +100°C thats the specification of the LED's what im wondering is, what would be the best and safest way to wire these up? ideally i'd actually like to plug them into the mains, or even running them off an AC-DC adapter. what kind of voltage would i require and should i just wire them in series, one after the other? or is there a better way to do this? the purpose is to build a 17 inch by 3 inch LED light bar any help would be great! thanx
Take the forward voltage to be 3.5V, and the typical forward current to be 25mA. You can put three LEDs in series, which is a total forward voltage of 10.5V, off a 12V supply rail, with an appropriate current limiting resistor in series. I'll leave the choice of appropriate resistance value for you to determine. You can put as many of these series LEDs/resistor combinations in parallel as desired. A 12V DC mains adaptor/plugpack/wall-wart/power brick/whatever should be very easy to find. It won't need to handle much power capacity.