Using Ardunio Mega 2560 to drive RGB LED lighting.

Projects General Guidance
1

Hello,

I have used the Mega 2560 to drive 40 inches of RGB LED strip lights without any problem. The power
required is 10 Volts at about 500 mA.

In my design, I have used Bit 9, 10 and 11 for outputs to the RGB LED strip lights. The 4th LEG of the
LED strip lights are connected to the 10 Volt power source. This is the same source of power for the
Mega 2560.

I have connected Bit9 to the Base of a TIP 120. The collector is then connected to the R terminal of
the LED strip and the Emmiter is connected to ground. I have repeated the same thing for Bit 10 and
Bit 11. Each TIP 120 can provide up to 5 Amp.

My question is, can I add more strip LEDs to the same link without damaging the Mega 2560 board?
I do not have any resistors between BITs output of the Mega2560 to the Base of the TIP 120s.
Should I add one to protect the MEGA2560. If so what value?

I have attached the design for your reference.

Thank You for your time

Best Regards

Bobby

Design.GIF
Design.GIF835×427 13.6 KB

2

Yes, you should have 150 ohm resistor in series to base to limit the Arduino output current.

You can add more LEDs until you smoke the transistors.
Then switch to logic level, low Rds N-channel MOSFETs for cooler operation.

Less expensive too

3

Hello,

Thank you for your time.

Best Regards
Bahram