Problems with transistor circuit

Other Hardware General Electronics
1

Hello!

I have a problem with my Arduino-Project. I am trying to light up some LED-stripes, which need 12V and take ~5 Watts.

For this I want to use some MOSFET IRF3708 transistors to light up the LEDs. My 12V Power source also Powers my Arduino Nano. The Digital Pins on the Arduino are set to "Output" and one PIN should switch one transistor. It basically works, but unfortunately it behaves just the wrong way round. :frowning: :o

When I set the digital PIN to HIGH, the transistor does not switch. The LEDs are staying dark. But as soon as I set the digital PIN to LOW, the transistor switches and the LEDS light up!

What am I doing wrong?

In the cicuit I have only drawn one LED-Stripe with transistor. But in total I have 3.

20160210_231317.jpg
20160210_231317.jpg1944×2592 672 KB

2

Perhaps you should get the pinout right, you've got it wrong.

3

Hi,
Can you indicate what the pins on the MOSFET are please, check the data sheet as to what pin is what, Gate, Drain, Source.
Is the MOSFET a logic input type?

You are best to have a 470R resistor in series with the wire from the D2 pin to the Gate, and a 10K resistor from the MOSFET Gate to Source.

Can you please post a copy of your sketch, using code tags?
They are made with the </> icon in the reply Menu.
See section 7 http://forum.arduino.cc/index.php/topic,148850.0.html

Tom... :slight_smile:

4

Yes the IRF3708 is logic level, as I said the OP got the pinout plain wrong.