Controlling 12v DC LED strips using Arduino UNO

Question

I have 2 LED strips with 6 LEDs on each. They use a 12V power supply.

My question, how can I use them like regular LEDs using Arduino UNO? Without any MOSFETS or transistors if possible.

And can I use PWM?

• Gerben: The only way is to cut out the individual leds an solder some wires to them, so you can connect them directly to the Arduino (with a resistor).
• Gerben: Do you have a picture? And are you sure it's 12v? As 8 LEDs is a weird number.
• YaddyVirus: its 6 actually.. my bad @Gerben
• Gerben: That makes more sense. Two sets of 3 LEDs in series.

Answer 1

It's not safe for the MCU without transistors or so.

You can use some kind of LED driver (for example TLC5940 with on chip PWM) or ULN2003 as 8 channel low side switch (instead of 8 transistors, PWM is possible if you do it programmatically) or many others.

With single transistor it looks like: enter image description here

Where R_1 can be about 1K and transistor can be any NPN that could handle led current.

• YaddyVirus: so what transistor do I actually need? and in case I do use a transistor, how am I going to wire the enitre setup?