Correct transistor?


I want to control ~150 SMD5050 LEDs (and 50 WS2811) with my UNO. I got some Toshiba K3878 transistors but I am not shure if I can use them... (there is so much info on this sheet)

What is the maximum currency these transistors can endure? How much do 150 LEDs drain? And what is the Voltage with which I can/should open the gate?

Soory for these noob questions :S

Thank you!

How much do 150 LEDs drain?

150 times as much as one if in parallel. How much does one drain - you didn't tell us.

The 2SK3878 is a horribly poor performance device and not logic-level, entirely wrong. You want a low on-resistance, logic-level, modern MOSFET.

(Actually the 2SK3878 is probably a superb performer at 750V, which is what its good at, but totally wrong for low voltage)

Its specified as 1.3 ohms worst-case at Vgs=10V. You want a device more like 0.01 ohms at Vgs=4.5V.

What power supply voltage are you using? Can you run the LEDs in series strings? What actual LEDs are the 5050 SMT ones?

Bought the LED strip from a Chinese seller, not much information there (except the strip is running on 12V) and "LED type: SMD 5050". So I suppose: I bought without power supply so I have to find/buy one if I know how much the controllers + LED will need.

I believe the WS2811 is a driver chip, so you don't need any transistors if you are driving LEDs with it.

Bought the LED strip from a Chinese seller, not much information there (except the strip is running on 12V)

That's usually a very-bad start...

If you buy stuff from reputable suppliers you can get a manufacturer's part number and/or datasheet. Sites like Adafruit and SparkFun usually have that plus additional information.

Sometimes you can get-away with no specs or datasheet if you really know what you are doing or unless you are a really good "hacker" and good at "figuring things out" and "making it work", but there are always risks with that.

Take a picture of one section of the strip (between two cut lines), and post it. Leo..

No point with the pictures, its a 12V LED strip, the only important thing is measuring the current it draws at 12V.

I have a 12V/2A power supply from another (shorter) all-in-one LED strip, do you guys think that 2A is enough for 150 LED? (i dont want to fry the supply) And how do I measure the current drawn when all LEDs are white when I cannot talk to the controllers? Whithout data input the LEDs remain off.