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Topic: Transistor Recomendation (Read 747 times) previous topic - next topic

YodaHart

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!

madworm

#1
Dec 22, 2011, 07:47 pm Last Edit: Dec 22, 2011, 07:57 pm by madworm Reason: 1
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.
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MarkT

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)
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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!

retrolefty


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.


madworm

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

page 8.

It is somewhat hidden.
• Upload doesn't work? Do a loop-back test.
• There's absolutely NO excuse for not having an ISP!
• Your AVR needs a brain surgery? Use the online FUSE calculator.
My projects: RGB LED matrix, RGB LED ring, various ATtiny gadgets...
• Microsoft is not the answer. It is the question, and the answer is NO!

YodaHart

Duh....I totally missed the "Lead Assignments" on the right of the diagram.  :smiley-roll:

madworm

They should've printed that on page 1. The TO-220 package is the only one they talk about anyway.
• Upload doesn't work? Do a loop-back test.
• There's absolutely NO excuse for not having an ISP!
• Your AVR needs a brain surgery? Use the online FUSE calculator.
My projects: RGB LED matrix, RGB LED ring, various ATtiny gadgets...
• Microsoft is not the answer. It is the question, and the answer is NO!

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