Correct transistor?

Hi,

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) http://www.toshiba.com/taec/components2/Datasheet_Sync/201005/DST_2SK3878-TDE_EN_12100.pdf

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: http://e-radionica.com/productdata/RGB5050LED.pdf 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.