Transistor Recomendation

I'm working on my first Arduino project and learning quite a bit as I'm going. I would like to control a few CPU fans from the Arduino using an external power supply. I'm hoping that I can use a transistor or small relay that can be controlled by a digital output pin on the Arduino. It wouldn't have to be a variable control, just on and off. I already have the external power supply of 12V and 1A to power 5-6 fans. What would be the best transistor or relay to use?

Thanks!

You want a 'logic level n-channel mosfet'. They're not expensive.

One of many example would be an IRLZ44N.

Except for the obvious voltage/current capabilities, you need to watch out for the R-DS(on) value at a gate-voltate of 5V (see the datasheets). The value should be well below 0.050 Ohm.

You will find tutorials for how to wire these thing up correctly.

Or a bipolar switching transistor that can handle 1A and has high gain (minimum 100 sounds good) - I am always in awe of the tiny little ZTX851, though its expensive (5A current rating, 20A pulse)

Thanks for the help! I finally got my IRLZ44N in the mail. How do I know which is the gate, drain and source? I don’t see it anywhere in the datasheet.

Thanks again!

YodaHart: Thanks for the help! I finally got my IRLZ44N in the mail. How do I know which is the gate, drain and source? I don't see it anywhere in the datasheet.

Thanks again!

Show us the link to the datasheet, perhaps we can find it for you.

http://www.irf.com/product-info/datasheets/data/irlz44n.pdf

page 8.

It is somewhat hidden.

Duh....I totally missed the "Lead Assignments" on the right of the diagram. :roll_eyes:

They should've printed that on page 1. The TO-220 package is the only one they talk about anyway.