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I need to power 150 led's, and Im not sure how.? Answered

The LED's I want to use have this as a data sheet:

Emitted Colour : White
Size (mm) : 10mm
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 25000
Life Rating : 100,000 Hours
Viewing Angle : 20 ~ 25 Degree
Absolute Maximum Ratings (Ta=25°C)
Max Power Dissipation : 80mw
Max Continuous Forward Current : 30mA
Max Peak Forward Current : 75mA
Reverse Voltage : 5~6V

Im going to be using 150 of them and was told my arduino cant power them all and I need to get/make a "led driver" So Im not exactly sure what I need to make to power them, and not blow up my arduino. Any help?


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9 years ago

Here are 5 general LED drivers.
You don't write how you plan to light 150  LEDs. 
Do you turn them all on at once, flash them, or draw matrix images.
  1. First pic is a direct uP driving a single LED .
  2. A uP driving three LEDs. If you don't turn them on all at once,  you can drive as many LEDs as the uP has output pins.
  3. Here you can drive LEDs from a higher voltage and some in series too. Each MOSFET hardly loads the uP,  you can do as many MOSFETs  as you have I/O pins.
  4. This demonstrates how one MOSFET can drive a lot of LEDs.
  5. The last is PWM  (Pulse Width Modulation) of MOSFETs driving LEDs from different voltages.  A buffer is used for driving the capacitive load of the MOSFET gates for unsmeared PWM.
Hope this help give you some help. .  .  .   .  .  .   A
The Skinnerz
The Skinnerz

9 years ago

In total, that's 4.5A continuous, so yes, you will need an additional switching circuit.

The best option is probably to use a MOSFET, as they can easily switch high currents, and require only a small heatsink (may even be unnecessary) and a pull-down resistor. There are lots of details about on their selection and use.

As for supplying the power, it would be best to go with a regulated DC power supply, with a rating of at least 5A, preferably more.


9 years ago

A relay that is switched from the output of the arduino.