12V Led Strip PWM

Other Hardware General Electronics
1

Hi guys

I've buyed some RGB-Led Strips common cathode. And now i like to control them from my Arduino.

Because they are common cathode strips i need to control them with a pnp-transistor, right? So, i've buyed three IRF5303 Mosfets.
http://www.redrok.com/MOSFET_IRF5305_-55V_-31A_6mO_Vth-4.0_TO-220.pdf

My Problem is how to control this Mosfets from the Arduino?
When connect 12v + to the drain and the + from the led to source the led is on. but how can i use the p-channel mosfet as a switch to turn off the led's.

thanks in advanche
paynoise

ps: sorry for my bad english...

2

You can do something like this:

http://ruggedcircuits.com/html/circuit__11.html

Replace the +6V in the schematic with your +12V (and the AOD417 with your IRF5303).

--
The Gadget Shield: accelerometer, RGB LED, IR transmit/receive, speaker, microphone, light sensor, potentiometer, pushbuttons

3

If you'd chosen a logic-level p-channel MOSFET you could have simply level-shifted with a zener diode and a pull-up on the gate... You'll need an NPN or n-channel transistor to drive the gate with full voltage swing.

4

@Rugged Circuits

can i use this 9014 (HTTP 301 This page has been moved)transistors instead of this 2N7000? Can i use the same resistors which you used in the circuit?

5

Yes, that should work. I don't think the resistors will need to change.

--
Beat707: MIDI drum machine / sequencer / groove-box for Arduino

6

thanks a lot. i'll try it this evening...